Trying to work on small use case where i have to add string of websites in a queue. if the site repeats then i have to update the numberofVisits+1. Else i would add that object into the queue. Something wrong with updateCount code. Please let me know
here is the code snippet. I am unable to move forward on this.
public CLassName(String url, int numVisits) {
this.url = url;
this.numVisits = numVisits;
}
public int getNumVisits() {
return this.numVisits;
}
public String getUrl() {
return this.url;
}
public void setNumVisits(int updatedNumVisits) {
this.numVisits = updatedNumVisits;
}
private static Queue<ClassName> sites = new LinkedList<ClassName>();
// Method to find the website in the queue and increment the visited count by 1, adding new node in case website is not found
public static void update(String url) {
//code should go in here. // THis is wrong code
if (sites.isEmpty()) sites.add(new ClassName(url,1));
while(!sites.isEmpty()) {
String tmpUrl = sites.peek().getUrl();
int numVisits = sites.peek().getNumVisits();
if(tmpUrl!=null && tmpUrl.equalsIgnoreCase(url)) {
sites.add(new ClassName(tmpUrl,numVisits+1));
} else if(tmpUrl!=null){
sites.add(new ClassName(tmpUrl,numVisits));
} else {
sites.add(new ClassName(url,1));
}
}
}
public static void main(String[] args) {
String[] visitedSites = { "www.google.co.in", "www.google.co.in", "www.facebook.com", "www.upgrad.com", "www.google.co.in", "www.youtube.com",
"www.facebook.com", "www.facebook.com", "www.google.co.in", "www.microsoft.com", "www.9gag.com", "www.netflix.com",
"www.netflix.com", "www.9gag.com", "www.microsoft.com", "www.amazon.com", "www.amazon.com", "www.uber.com", "www.amazon.com",
"www.microsoft.com" };
for (String url : visitedSites) {
update(url);
}
Thanks for the recommendation. I did a small tweek to address the problem.
I did not add Dummy site
Added a counter and incremented so that it is always < the size of queue
Here is my solution and it works
public static void update(Queue<String> sites,String url,int numberOfVisits)
{
if ( sites.isEmpty()) sites.add(url); // first time
boolean flag = false;
int counter = 0
while (!sites.empty && counter<sites.size()) //go over all the urls in the queue
{
if (sites.head().equalsIgnoreCase(url))
{
flag = true;
break;
}
sites.insert(sites.remove()); //removing the head and inserting it to the end of the queue
counter ++;
}
if (!flag==true) {
numberOfVisits=numberOfVisits+1;
}
else {
sites.insert(url);
}
}
the update method just could be like this;
boolean increased = false;
Iterator<ClassName> statIterator = sites.iterator();
while (statIterator.hasNext()) {
ClassName st = statIterator.next();
if (st.getUrl().equals(url)) {
st.setNumVisits(st.getNumVisits()+1);
increased = true;
break;
}
}
if (!increased) {
sites.add(new ClassName(url,1));
}
I just recently used android:TabbedPage.ToolbarPlacement="Bottom". I used to have the following code:
void TabLayout.IOnTabSelectedListener.OnTabUnselected(TabLayout.Tab tab)
{
var playPage = Element.CurrentPage as NavigationPage;
if (!(playPage.RootPage is PhrasesFrame))
return;
var tabLayout = (TabLayout)ViewGroup.GetChildAt(1);
var playTab = tabLayout.GetTabAt(4);
tab.SetText("Play");
tab.SetIcon(Resource.Drawable.ionicons_2_0_1_play_outline_25);
App.pauseCard = true;
}
Anyone knows how can I implement this with ToolbarPlacement="Bottom" ? I have implemented both BottomNavigationView.IOnNavigationItemSelectedListener, BottomNavigationView.IOnNavigationItemReselectedListener but can't find any reference for UnselectedTab if there is any.
Edit:
Previous custom renderer using the default tab position and implementing TabLayout:
namespace Japanese.Droid
{
public class MyTabbedPageRenderer: TabbedPageRenderer, TabLayout.IOnTabSelectedListener
{
ViewPager viewPager;
TabLayout tabLayout;
bool setup;
public MyTabbedPageRenderer(Context context): base(context){ }
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
// More codes here
}
void TabLayout.IOnTabSelectedListener.OnTabReselected(TabLayout.Tab tab)
{
UpdateTab(tab);
}
void TabLayout.IOnTabSelectedListener.OnTabSelected(TabLayout.Tab tab)
{
UpdateTab(tab);
}
void TabLayout.IOnTabSelectedListener.OnTabUnselected(TabLayout.Tab tab)
{
var playPage = Element.CurrentPage as NavigationPage;
if (!(playPage.RootPage is PhrasesFrame))
return;
var tabLayout = (TabLayout)ViewGroup.GetChildAt(1);
var playTab = tabLayout.GetTabAt(4);
tab.SetText("Play");
tab.SetIcon(Resource.Drawable.ionicons_2_0_1_play_outline_25);
App.pauseCard = true;
}
void UpdateTab(TabLayout.Tab tab)
{
// To have the logic only on he tab on position 1
if (tab == null || tab.Position != 4)
{
return;
}
if (tab.Text == "Play")
{
tab.SetText("Pause");
tab.SetIcon(Resource.Drawable.ionicons_2_0_1_pause_outline_22);
App.pauseCard = false;
}
else
{
tab.SetText("Play");
tab.SetIcon(Resource.Drawable.ionicons_2_0_1_play_outline_25);
App.pauseCard = true;
}
}
}
}
Current custom renderer using the ToolbarPlacement="Bottom":
namespace Japanese.Droid
{
public class BottomTabPageRenderer : TabbedPageRenderer, BottomNavigationView.IOnNavigationItemSelectedListener, BottomNavigationView.IOnNavigationItemReselectedListener
{
public BottomTabPageRenderer(Context context) : base(context) { }
protected override void OnElementChanged(ElementChangedEventArgs<TabbedPage> e)
{
base.OnElementChanged(e);
// More codes here
}
bool BottomNavigationView.IOnNavigationItemSelectedListener.OnNavigationItemSelected(IMenuItem item)
{
base.OnNavigationItemSelected(item);
UpdateTab(item)
}
void BottomNavigationView.IOnNavigationItemReselectedListener.OnNavigationItemReselected(IMenuItem item)
{
UpdateTab(item);
}
void UpdateTab(IMenuItem item)
{
var playTabId = 4;
var title = item.TitleFormatted.ToString();
if (item == null || item.ItemId != playTabId)
{
return;
}
if (item.ItemId == playTabId)
{
if (title == "Play")
{
item.SetTitle("Pause");
item.SetIcon(Resource.Drawable.ionicons_2_0_1_pause_outline_22);
App.pauseCard = false;
}
else
{
item.SetTitle("Play");
item.SetIcon(Resource.Drawable.ionicons_2_0_1_play_outline_25);
App.pauseCard = true;
}
}
}
}
}
So now my problem is I don't have any idea how will I implement the TabLayout.IOnTabSelectedListener.OnTabUnselected in the new custom renderer.
There is no official stuff for OnTabReselected event for TabbedPage's bottom navigation or
BottomNavigationView because It doesn't use TabLayout.Tab for a start. Many overridden methods of TabbedPageRenderer not being called like SetTabIcon. If you are using IOnTabSelectedListener interface(As your first part of code) you have three methods to use.
void OnTabReselected(Tab tab);
void OnTabSelected(Tab tab);
void OnTabUnselected(Tab tab);
But when it comes to BottomNavigationView interface you have only two methods
void OnNavigationItemReselected
bool OnNavigationItemSelected
So we don't have built in OnTabUnselected method. Here you need to write custom code to make unseleted event.
I have tried this code without using custom renderer using 4 tabs pages & the xaml of tabbed written in MailPage.xaml file. First declare List<string> in App.xaml.cs file to store Title of all tabs
public static List<string> Titles {get;set;}
Add tabs pages title in above list from MainPage.xaml.cs file's OnAppearing method
protected override void OnAppearing()
{
for (int i = 0; i < this.Children.Count; i++)
{
App.Titles.Add(this.Children[i].Title);
}
}
Now go to your MyTabbedPage class in which is available in shared project.
public class MyTabbedPage : Xamarin.Forms.TabbedPage
{
string selectedTab = string.Empty;
string unSelectedTab = string.Empty;
bool isValid;
public MyTabbedPage()
{
On<Xamarin.Forms.PlatformConfiguration.Android>().SetToolbarPlacement(ToolbarPlacement.Bottom);
this.CurrentPageChanged += delegate
{
unSelectedTab = selectedTab;
selectedTab = CurrentPage.Title;
if (App.Titles != null)
isValid = true;
else
App.Titles = new List<string>();
if (isValid)
{
MoveTitles(selectedTab);
//Pass 0 index for tab selected & 1 for tab unselected
var unSelecteTabTitle = App.Titles[1];
//TabEvents(1); here you know which tab unseleted call any method
}
};
}
//This method is for to moving selected title on top of App.Titles list & unseleted tab title automatic shifts at index 1
void MoveTitles(string selected)
{
var holdTitles = App.Titles;
if (holdTitles.Count > 0)
{
int indexSel = holdTitles.FindIndex(x => x.StartsWith(selected));
holdTitles.RemoveAt(indexSel);
holdTitles.Insert(0, selected);
}
App.Titles = holdTitles;
}
}
Or you can make swith case like this
void TabEvents(int index)
{
switch (index)
{
case 0:
//Tab selected
break;
case 1:
//Tab unselected
break;
}
}
Few things I should mention that MainPage.xaml.cs file inheriting MyTabbedPage
public partial class MainPage : MyTabbedPage
Structure of MainPage.xaml file
<?xml version="1.0" encoding="utf-8" ?>
<local:MyTabbedPage
<TabbedPage.Children>
<NavigationPage Title="Browse">
</NavigationPage>
</TabbedPage.Children>
</local:MyTabbedPage>
Answer seems long but hope it help you.
As per G.Hakim's suggestion, I was able to do what I wanted to do by capturing the tab item I wanted to work on and do the necessary actions in BottomNavigationView.IOnNavigationItemSelectedListener.OnNavigationItemSelected.
namespace Japanese.Droid
{
public class BottomTabPageRenderer : TabbedPageRenderer, BottomNavigationView.IOnNavigationItemSelectedListener, BottomNavigationView.IOnNavigationItemReselectedListener
{
// same as above
bool BottomNavigationView.IOnNavigationItemSelectedListener.OnNavigationItemSelected(IMenuItem item)
{
base.OnNavigationItemSelected(item);
if(item.ItemId == 4 && item.TitleFormatted.ToString() == "Play")
{
item.SetTitle("Pause");
item.SetIcon(Resource.Drawable.ionicons_2_0_1_pause_outline_22);
App.pauseCard = false;
playTab = item;
}
if(item.ItemId !=4 && playTab.TitleFormatted.ToString() == "Pause")
{
playTab.SetTitle("Play");
playTab.SetIcon(Resource.Drawable.ionicons_2_0_1_play_outline_25);
App.pauseCard = true;
}
return true;
}
// same as above
}
}
If you are searching for a full polylines, pins, tiles, UIOptions (and 3D effects soon) renderings/implementations, you should take a loot at the public github I made at XamarinByEmixam23/..../Map.
I search a lot but I still have the same problem:
How can I update, refresh or reload the Xamarin.Forms.Maps?
In the class definition (class CustomMap : Map), there is no method to update the maps.. Maybe a MVVM logic can solves the problem, but I can't find it on the Web..
I followed this tutorial for the maps : Working with maps
To customise it, I followed this tutorial : Highlight a Route on a Map
So, after these tutorials (I made the same things, no changes), I tried with 2 RouteCoordinates which gave me a straight line... I then made an algorithm which works perfectly.
DirectionMap
public class DirectionMap
{
public Distance distance { get; set; }
public Duration duration { get; set; }
public Address address_start { get; set; }
public Address address_end { get; set; }
public List<Step> steps { get; set; }
public class Distance
{
public string text { get; set; }
public int value { get; set; }
}
public class Duration
{
public string text { get; set; }
public int value { get; set; }
}
public class Address
{
public string text { get; set; }
public Position position { get; set; }
}
public class Step
{
public Position start { get; set; }
public Position end { get; set; }
}
}
ResponseHttpParser
public static void parseDirectionGoogleMapsResponse(HttpStatusCode httpStatusCode, JObject json, Action<DirectionMap, string> callback)
{
switch (httpStatusCode)
{
case HttpStatusCode.OK:
DirectionMap directionMap = null;
string strException = null;
try
{
directionMap = new DirectionMap()
{
distance = new DirectionMap.Distance()
{
text = (json["routes"][0]["legs"][0]["distance"]["text"]).ToString(),
value = Int32.Parse((json["routes"][0]["legs"][0]["distance"]["value"]).ToString())
},
duration = new DirectionMap.Duration()
{
text = (json["routes"][0]["legs"][0]["duration"]["text"]).ToString(),
value = Int32.Parse((json["routes"][0]["legs"][0]["duration"]["value"]).ToString())
},
address_start = new DirectionMap.Address()
{
text = (json["routes"][0]["legs"][0]["start_address"]).ToString(),
position = new Position(Double.Parse((json["routes"][0]["legs"][0]["start_location"]["lat"]).ToString()), Double.Parse((json["routes"][0]["legs"][0]["start_location"]["lng"]).ToString()))
},
address_end = new DirectionMap.Address()
{
text = (json["routes"][0]["legs"][0]["end_address"]).ToString(),
position = new Position(Double.Parse((json["routes"][0]["legs"][0]["end_location"]["lat"]).ToString()), Double.Parse((json["routes"][0]["legs"][0]["end_location"]["lng"]).ToString()))
}
};
bool finished = false;
directionMap.steps = new List<Step>();
int index = 0;
while (!finished)
{
try
{
Step step = new Step()
{
start = new Position(Double.Parse((json["routes"][0]["legs"][0]["steps"][index]["start_location"]["lat"]).ToString()), Double.Parse((json["routes"][0]["legs"][0]["steps"][index]["start_location"]["lng"]).ToString())),
end = new Position(Double.Parse((json["routes"][0]["legs"][0]["steps"][index]["end_location"]["lat"]).ToString()), Double.Parse((json["routes"][0]["legs"][0]["steps"][index]["end_location"]["lng"]).ToString()))
};
directionMap.steps.Add(step);
index++;
}
catch (Exception e)
{
finished = true;
}
}
}
catch (Exception e)
{
directionMap = null;
strException = e.ToString();
}
finally
{
callback(directionMap, strException);
}
break;
default:
switch (httpStatusCode)
{
}
callback(null, json.ToString());
break;
}
}
I just get the distance and duration for some private calculs and get each step that I put into a List<>;
When everything is finished, I use my callback which bring us back to the controller (MapPage.xaml.cs the XAML Form Page (Xamarin Portable))
Now, everything becomes weird. It's like the map doesn't get that changes are made
public partial class MapPage : ContentPage
{
public MapPage()
{
InitializeComponent();
setupMap();
setupMapCustom();
}
public void setupMapCustom()
{
customMap.RouteCoordinates.Add(new Position(37.785559, -122.396728));
customMap.RouteCoordinates.Add(new Position(37.780624, -122.390541));
customMap.RouteCoordinates.Add(new Position(37.777113, -122.394983));
customMap.RouteCoordinates.Add(new Position(37.776831, -122.394627));
customMap.MoveToRegion(MapSpan.FromCenterAndRadius(new Position(37.79752, -122.40183), Xamarin.Forms.Maps.Distance.FromMiles(1.0)));
}
public async void setupMap()
{
customMap.MapType = MapType.Satellite;
string origin = "72100 Le Mans";
string destination = "75000 Paris";
HttpRequest.getDirections(origin, destination, callbackDirections);
customMap.RouteCoordinates.Add(await MapUtilities.GetMapPointOfStreetAddress(origin));
Position position = await MapUtilities.GetMapPointOfStreetAddress(destination);
//customMap.RouteCoordinates.Add(position);
var pin = new Pin
{
Type = PinType.Place,
Position = position,
Label = "Destination !!",
};
customMap.Pins.Add(pin);
}
private async void callbackDirections(Object obj, string str)
{
if (obj != null)
{
DirectionMap directionMap = obj as DirectionMap;
foreach (Step step in directionMap.steps)
{
customMap.RouteCoordinates.Add(step.start);
System.Diagnostics.Debug.WriteLine("add step");
}
customMap.RouteCoordinates.Add(directionMap.address_end.position);
System.Diagnostics.Debug.WriteLine("add last step");
}
else
{
System.Diagnostics.Debug.WriteLine(str);
}
}
}
I run my app, everything works until it's something fast, because of the time spent by my algorithm etc, the callback is coming too late and then I need to refresh, reload or update my map... Anyway, I need to update my map in the future, so... If anyone can help, this one is welcome !
EDIT 1
I took a look at your answer ( thank a lot ! ;) ) but it doesn't works :/
I updated CustomMap as you did
public class CustomMap : Map
{
public static readonly BindableProperty RouteCoordinatesProperty =
BindableProperty.Create<CustomMap, List<Position>>(p => p.RouteCoordinates, new List<Position>());
public List<Position> RouteCoordinates
{
get { return (List<Position>)GetValue(RouteCoordinatesProperty); }
set { SetValue(RouteCoordinatesProperty, value); }
}
public CustomMap()
{
RouteCoordinates = new List<Position>();
}
}
Same for CustomMapRenderer (Droid)
public class CustomMapRenderer : MapRenderer, IOnMapReadyCallback
{
GoogleMap map;
Polyline polyline;
protected override void OnElementChanged(Xamarin.Forms.Platform.Android.ElementChangedEventArgs<Xamarin.Forms.View> e)
{
base.OnElementChanged(e);
if (e.OldElement != null)
{
// Unsubscribe
}
if (e.NewElement != null)
{
((MapView)Control).GetMapAsync(this);
}
}
protected override void OnElementPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (this.Element == null || this.Control == null)
return;
if (e.PropertyName == CustomMap.RouteCoordinatesProperty.PropertyName)
{
UpdatePolyLine();
}
}
private void UpdatePolyLine()
{
if (polyline != null)
{
polyline.Remove();
polyline.Dispose();
}
var polylineOptions = new PolylineOptions();
polylineOptions.InvokeColor(0x66FF0000);
foreach (var position in ((CustomMap)this.Element).RouteCoordinates)
{
polylineOptions.Add(new LatLng(position.Latitude, position.Longitude));
}
polyline = map.AddPolyline(polylineOptions);
}
public void OnMapReady(GoogleMap googleMap)
{
map = googleMap;
UpdatePolyLine();
}
}
So, for the last change, in my MapPage.xaml.cs I made changes in the callbackDirections as you explained (I hope I did good)
private async void callbackDirections(Object obj, string str)
{
if (obj != null)
{
Device.BeginInvokeOnMainThread(() =>
{
DirectionMap directionMap = obj as DirectionMap;
var list = new List<Position>(customMap.RouteCoordinates);
foreach (Step step in directionMap.steps)
{
list.Add(directionMap.address_end.position);
System.Diagnostics.Debug.WriteLine("add step");
}
System.Diagnostics.Debug.WriteLine("last step");
customMap.RouteCoordinates = list;
System.Diagnostics.Debug.WriteLine("finished?");
});
}
else
{
System.Diagnostics.Debug.WriteLine(str);
}
}
The map is still doesn't display the polyline :/ I only made these changes, I didn't change anything else from my previous code.
I didn't tell you, but I'm not an expert in MVVM binding, so if I forget something, I'm sorry :/
EDIT 2
So after your answer and some read, read and re-read of your answer, there is my "test code" in MapPage.xaml.cs
public MapPage()
{
InitializeComponent();
//HttpRequest.getDirections(origin, destination, callbackDirections);
Device.BeginInvokeOnMainThread(() =>
{
customMap.RouteCoordinates = new List<Position>
{
new Position (37.797534, -122.401827),
new Position (37.776831, -122.394627)
};
});
//setupMap();
//setupMapCustom();
}
Because it doesn't works (for me), I took a look at my code and then, I saw that public static readonly BindableProperty RouteCoordinatesProperty =
BindableProperty.Create<CustomMap, List<Position>>(
p => p.RouteCoordinates, new List<Position>()); was deprecated..
So I red on this post a different way to implement this binding, but it also said that this way is deprecated SEE HERE... I also saw some tutorials about binding which says that they put some code into their xaml, let me remember you mine
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:NAMESPACE;assembly=NAMESPACE"
x:Class="NAMESPACE.Controlers.MapPage">
<ContentPage.Content>
<local:CustomMap x:Name="customMap"/>
</ContentPage.Content>
</ContentPage>
I'm not using something as ItemSource="{PolylineBindable}"
The custom renderer from the example is not made for dynamic updating the path. It is just implemented for the case, where all points of the paths are known before initializing the map / drawing the path the first time. So you have this race condition, you ran into, because you are loading the directions from a web service.
So you have to do some changes:
RouteCoordinates must be a BindableProperty
public class CustomMap : Map
{
public static readonly BindableProperty RouteCoordinatesProperty =
BindableProperty.Create<CustomMap, List<Position>>(p => p.RouteCoordinates, new List<Position>());
public List<Position> RouteCoordinates
{
get { return (List<Position>)GetValue(RouteCoordinatesProperty); }
set { SetValue(RouteCoordinatesProperty, value); }
}
public CustomMap ()
{
RouteCoordinates = new List<Position>();
}
}
Update the Polyline whenever the coordinates change
Move the creation of the polyline from OnMapReady to UpdatePolyLine
call UpdatePolyLine from OnMapReady and OnElementPropertyChanged
public class CustomMapRenderer : MapRenderer, IOnMapReadyCallback
{
GoogleMap map;
Polyline polyline;
protected override void OnElementChanged(Xamarin.Forms.Platform.Android.ElementChangedEventArgs<View> e)
{
base.OnElementChanged(e);
if (e.OldElement != null)
{
// Unsubscribe
}
if (e.NewElement != null)
{
((MapView)Control).GetMapAsync(this);
}
}
protected override void OnElementPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (this.Element == null || this.Control == null)
return;
if (e.PropertyName == CustomMap.RouteCoordinatesProperty.PropertyName)
{
UpdatePolyLine();
}
}
private void UpdatePolyLine()
{
if (polyline != null)
{
polyline.Remove();
polyline.Dispose();
}
var polylineOptions = new PolylineOptions();
polylineOptions.InvokeColor(0x66FF0000);
foreach (var position in ((CustomMap)this.Element).RouteCoordinates)
{
polylineOptions.Add(new LatLng(position.Latitude, position.Longitude));
}
polyline = map.AddPolyline(polylineOptions);
}
public void OnMapReady(GoogleMap googleMap)
{
map = googleMap;
UpdatePolyLine();
}
}
Setting the data
Updating the positions changes a bit. Instead of adding the positions to the existing list, you have to (create a new list) and set it to RouteCoordinates. You can use Device.BeginInvokeOnMainThread to ensure, that the operation is performed on the UI thread. Else the polyline will not update.
Device.BeginInvokeOnMainThread(() =>
{
customMap.RouteCoordinates = new List<Position>
{
new Position (37.797534, -122.401827),
new Position (37.776831, -122.394627)
};
})
In your case it's something like
var list = new List<Position>(customMap.RouteCoordinates);
list.Add(directionMap.address_end.position);
customMap.RouteCoordinates = list;
Todo
On iOS you have now to implement a similar behavior (like UpdatePolyLine)
Note
That might not the most performant implementation, because you redraw everything instead of adding one point. But it's fine as long as you have no performance issues :)
I followed the tutorial available on Xamarin Docs and it worked for me with some changes based on #Sven-Michael Stübe answer
I load the coordinates from a WebService and then I create a separate List, and after this, I set the new list to the RouteCoordinates property on Custom Map.
Some changes are made on Android Renderer
I'm using MVVM.
CustomMap Class:
public static readonly BindableProperty RouteCoordinatesProperty =
BindableProperty.Create(nameof(RouteCoordinates), typeof(List<Position>), typeof(CustomMap), new List<Position>(), BindingMode.TwoWay);
public List<Position> RouteCoordinates
{
get { return (List<Position>)GetValue(RouteCoordinatesProperty); }
set { SetValue(RouteCoordinatesProperty, value); }
}
public CustomMap()
{
RouteCoordinates = new List<Position>();
}
ViewModel (Codebehind, in your case):
private async void LoadCoordinates(string oidAula, CustomMap mapa)
{
IsBusy = true;
var percurso = await ComunicacaoServidor.GetPercurso(oidAula); // Get coordinates from WebService
var pontos = percurso.Select(p => new Position(p.Latitude, p.Longitude)).ToList(); // Create coordinates list from webservice result
var latitudeMedia = percurso[percurso.Count / 2].Latitude;
var longitudeMedia = percurso[percurso.Count / 2].Longitude;
mapa.RouteCoordinates = pontos;
mapa.MoveToRegion(MapSpan.FromCenterAndRadius(new Position(latitudeMedia, longitudeMedia), Distance.FromMiles(1.0)));
IsBusy = false;
}
XAML:
<maps:CustomMap
AbsoluteLayout.LayoutFlags = "All"
AbsoluteLayout.LayoutBounds = "0, 0, 1, 1"
VerticalOptions = "FillAndExpand"
HorizontalOptions = "FillAndExpand"
x:Name = "PercursoMapa" />
Android Renderer:
public class CustomMapRenderer : MapRenderer
{
bool isDrawn;
protected override void OnElementChanged(ElementChangedEventArgs<Map> e)
{
base.OnElementChanged(e);
if (e.OldElement != null)
{
// Unsubscribe
}
if (e.NewElement != null)
Control.GetMapAsync(this);
}
protected override void OnElementPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if ((e.PropertyName == "RouteCoordinates" || e.PropertyName == "VisibleRegion") && !isDrawn)
{
var polylineOptions = new PolylineOptions();
polylineOptions.InvokeColor(0x66FF0000);
var coordinates = ((CustomMap)Element).RouteCoordinates;
foreach (var position in coordinates)
polylineOptions.Add(new LatLng(position.Latitude, position.Longitude));
NativeMap.AddPolyline(polylineOptions);
isDrawn = coordinates.Count > 0;
}
}
}
This example have more than 3600 points of location and the polyline shows correctly on device:
Screenshot
Building on these answers, here is what I did to get it to work on iOS. This allows changing the route even after the map is loaded, unlike the Xamarin sample.
Firstly, custom map class as per #Sven-Michael Stübe with the update from #Emixam23:
public class CustomMap : Map
{
public static readonly BindableProperty RouteCoordinatesProperty =
BindableProperty.Create(nameof(RouteCoordinates), typeof(List<Position>), typeof(CustomMap), new List<Position>(), BindingMode.TwoWay);
public List<Position> RouteCoordinates
{
get { return (List<Position>)GetValue(RouteCoordinatesProperty); }
set { SetValue(RouteCoordinatesProperty, value); }
}
public CustomMap()
{
RouteCoordinates = new List<Position>();
}
}
Next, the iOS custom renderer:
[assembly: ExportRenderer(typeof(CustomMap), typeof(CustomMapRenderer))]
namespace KZNTR.iOS
{
public class CustomMapRenderer : MapRenderer
{
MKPolylineRenderer polylineRenderer;
CustomMap map;
protected override void OnElementPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if ((this.Element == null) || (this.Control == null))
return;
if (e.PropertyName == CustomMap.RouteCoordinatesProperty.PropertyName)
{
map = (CustomMap)sender;
UpdatePolyLine();
}
}
[Foundation.Export("mapView:rendererForOverlay:")]
MKOverlayRenderer GetOverlayRenderer(MKMapView mapView, IMKOverlay overlay)
{
if (polylineRenderer == null)
{
var o = ObjCRuntime.Runtime.GetNSObject(overlay.Handle) as MKPolyline;
polylineRenderer = new MKPolylineRenderer(o);
//polylineRenderer = new MKPolylineRenderer(overlay as MKPolyline);
polylineRenderer.FillColor = UIColor.Blue;
polylineRenderer.StrokeColor = UIColor.Red;
polylineRenderer.LineWidth = 3;
polylineRenderer.Alpha = 0.4f;
}
return polylineRenderer;
}
private void UpdatePolyLine()
{
var nativeMap = Control as MKMapView;
nativeMap.OverlayRenderer = GetOverlayRenderer;
CLLocationCoordinate2D[] coords = new CLLocationCoordinate2D[map.RouteCoordinates.Count];
int index = 0;
foreach (var position in map.RouteCoordinates)
{
coords[index] = new CLLocationCoordinate2D(position.Latitude, position.Longitude);
index++;
}
var routeOverlay = MKPolyline.FromCoordinates(coords);
nativeMap.AddOverlay(routeOverlay);
}
}
}
And finally, adding a polyline to the map:
Device.BeginInvokeOnMainThread(() =>
{
customMap.RouteCoordinates.Clear();
var plist = new List<Position>(customMap.RouteCoordinates);
foreach (var point in track.TrackPoints)
{
plist.Add(new Position(double.Parse(point.Latitude, CultureInfo.InvariantCulture), double.Parse(point.Longitude, CultureInfo.InvariantCulture)));
}
customMap.RouteCoordinates = plist;
var firstpoint = (from pt in track.TrackPoints select pt).FirstOrDefault();
customMap.MoveToRegion(MapSpan.FromCenterAndRadius(new Position(double.Parse(firstpoint.Latitude, CultureInfo.InvariantCulture), double.Parse(firstpoint.Longitude, CultureInfo.InvariantCulture)), Distance.FromMiles(3.0)));
});
Not sure if this is the best way to do it, or the most efficient, I don't know much about renderers, but it does seem to work.
So after lot of searches and, of course, the answer of #Sven-Michael Stübe, you can have your proper maps which works on each platform "Android, iOS, WinPhone". Follow my code, then edit it following the #Sven-Michael Stübe's answer.
Once you finished everything, it could works (like for #Sven-Michael Stübe), but it also couldn't work (like for me). If it doesn't works, try to change the following code:
public static readonly BindableProperty RouteCoordinatesProperty =
BindableProperty.Create<CustomMap, List<Position>>(
p => p.RouteCoordinates, new List<Position>());
by
public static readonly BindableProperty RouteCoordinatesProperty =
BindableProperty.Create(nameof(RouteCoordinates), typeof(List<Position>), typeof(CustomMap), new List<Position>(), BindingMode.TwoWay);
See the documentation for more information about it. (Deprecated implementation)
Then the code works !
PS: You can have some troubles with the polyline at the end, which not following the road right, I'm working on it.
PS2: I'll also make a video to explain how to code your customMap to don't have to install a NuGet package, to be able to edit everything at the end ! (The first one will be in French, the second in English, this post will be edited when the video will be made)
Thank angain to #Sven-Michael Stübe !! Thank to up his answer as well :)
I have a search text-box in my app. In my database there are two column named English and Bangla. I can search either Bangla or English. there is a button beside search text-box.By default English search is activated. I can change the search option by clicking the button. It works correctly but problem is that the search is very slow.
search option selection code by clicking button is:
private void button5_Click(object sender, RoutedEventArgs e)
{
if (SearchMood % 2 != 0)
{
//search bangla column from the database
button5.Content = "Eng";
}
else {
//search english column from the database
button5.Content = "Bng";
}
SearchMood++;
}
Code for searching is:
private void textBox1_TextChanged(object sender, TextChangedEventArgs e)
{
List<dataLists> mylist = new List<dataLists>();
string word = textBox1.Text;
try
{
if (SearchMood % 2 == 0)// for english search
{
// show 5 words in listbox matched with entered text
var contacts = (from m in db.Dics where m.English.StartsWith(word) select new { m.English, m.Bangla }).Take(5);
string s1, s2;
try
{
foreach (var a in contacts)
{
s1 = a.English;
s2 = a.Bangla;
mylist.Add(new dataLists() { Eng = s1, Bng = s2 });
}
}
catch (Exception ex) { MessageBox.Show(ex.ToString()); }
listBox1.ItemsSource = mylist;
}
else // for bangla search
{
// show 5 words in listbox matched with entered text
var contacts = (from m in db.Dics where m.Bangla.StartsWith(word) select new { m.English, m.Bangla }).Take(5);
string s1, s2;
try
{
foreach (var a in contacts)
{
s1 = a.English;
s2 = a.Bangla;
mylist.Add(new dataLists() { Eng = s1, Bng = s2 });
}
}
catch (Exception ex) { MessageBox.Show(ex.ToString()); }
listBox1.ItemsSource = mylist;
}
}
catch { }
}
How can I increase the performance of searching??? Can anyone give any solution|???
N:B: My table creation script looks like
public System.Data.Linq.Table<Dic> Dics
{
get
{
return this.GetTable<Dic>();
}
}
public System.Data.Linq.Table<Learn_table> Learn_tables
{
get
{
return this.GetTable<Learn_table>();
}
}
}
[global::System.Data.Linq.Mapping.TableAttribute(Name="dic")]
public partial class Dic : INotifyPropertyChanging, INotifyPropertyChanged
{
private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(String.Empty);
private int _Serial;
private string _English;
private string _Bangla;
private System.Nullable<int> _Fav;
#region Extensibility Method Definitions
partial void OnLoaded();
partial void OnValidate(System.Data.Linq.ChangeAction action);
partial void OnCreated();
partial void OnSerialChanging(int value);
partial void OnSerialChanged();
partial void OnEnglishChanging(string value);
partial void OnEnglishChanged();
partial void OnBanglaChanging(string value);
partial void OnBanglaChanged();
partial void OnFavChanging(System.Nullable<int> value);
partial void OnFavChanged();
#endregion
public Dic()
{
OnCreated();
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Name="serial", Storage="_Serial", AutoSync=AutoSync.OnInsert, DbType="Int NOT NULL IDENTITY", IsPrimaryKey=true, IsDbGenerated=true)]
public int Serial
{
get
{
return this._Serial;
}
set
{
if ((this._Serial != value))
{
this.OnSerialChanging(value);
this.SendPropertyChanging();
this._Serial = value;
this.SendPropertyChanged("Serial");
this.OnSerialChanged();
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Name="english", Storage="_English", DbType="NVarChar(2000)")]
public string English
{
get
{
return this._English;
}
set
{
if ((this._English != value))
{
this.OnEnglishChanging(value);
this.SendPropertyChanging();
this._English = value;
this.SendPropertyChanged("English");
this.OnEnglishChanged();
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Name="bangla", Storage="_Bangla", DbType="NVarChar(2000)")]
public string Bangla
{
get
{
return this._Bangla;
}
set
{
if ((this._Bangla != value))
{
this.OnBanglaChanging(value);
this.SendPropertyChanging();
this._Bangla = value;
this.SendPropertyChanged("Bangla");
this.OnBanglaChanged();
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Name="fav", Storage="_Fav", DbType="Int")]
public System.Nullable<int> Fav
{
get
{
return this._Fav;
}
set
{
if ((this._Fav != value))
{
this.OnFavChanging(value);
this.SendPropertyChanging();
this._Fav = value;
this.SendPropertyChanged("Fav");
this.OnFavChanged();
}
}
}
public event PropertyChangingEventHandler PropertyChanging;
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void SendPropertyChanging()
{
if ((this.PropertyChanging != null))
{
this.PropertyChanging(this, emptyChangingEventArgs);
}
}
protected virtual void SendPropertyChanged(String propertyName)
{
if ((this.PropertyChanged != null))
{
this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
Your problem appears in using TextChanged event Handler. Place a breakpoint there and you will see it firing twice and hence causing the slow performance for you. It seems a bug in WP7 TextBox control.
Use KeyUp event handler, instead of textBox1_TextChanged
void textBox1_KeyUp(object sender, KeyEventArgs e)
{
//your code
}
Hope this solves your problem. !!
You can use of AutoCompleteBox rather than use of TextBox. AutoCompleteBox available in Microsoft.Phone.Control.Toolkit.
Execute you select query at once when you select language on buttonClick and assign result of your query to AutoCompleteBox.Itemsource. It should really increase search performance.
<toolkit:AutoCompleteBox x:Name="AutoBoxFood" Width="440" SelectionChanged="txtFodd_SelectionChanged" FilterMode="StartsWith" HorizontalAlignment="Left" Height="70"/>
Add indexes to the columns in the database file.