I want to binding a variable to a label which as a children in a grid.
the variable changed with a timer event.pls check my code help me found out where i am wrong.I can see the label init value is 0,but it won't update when the variable do.
public class DevicePage : ContentPage
{
IDevice device;
Label testLb = new Label();
System.Timers.Timer testtimer;
Grid gridView;
byte testt { get; set; } = 0;
GetSendData communicate;
private byte _maintext;
public byte MainText
{
get
{
return _maintext;
}
set
{
_maintext = value;
OnPropertyChanged();
}
}
public DevicePage(IDevice currDevice)
{
device = currDevice;
this.Title = "Status";
testtimer = new System.Timers.Timer();
testtimer.Interval = 1000;
testtimer.Elapsed += OnTimedEvent;
testtimer.Enabled = true;
gridView = new Grid();
testLb.Text = testt.ToString();
testLb.SetBinding(Label.TextProperty, ".");
testLb.BindingContext = MainText;
gridView.Children.Add(testLb, 0, 0);
this.Content = gridView;
}
private void OnTimedEvent(object sender, System.Timers.ElapsedEventArgs e)
{
MainText += 1;
}
after I implement INotifyPropertyChanged,testLb won't update either.But I change testLb.SetBinding(Label.TextProperty, "."); testLb.BindingContext = MainText; to testLb.SetBinding(Label.TextProperty, "MainText"); testLb.BindingContext = this; It works!
Related
I create a custom control for UILabel with custom Kern parameter.
[Register("CustomLabelView"), DesignTimeVisible(true)]
public class CustomLabelView : UILabel
{
private float _textLetterSpacing;
public CustomLabelView(IntPtr handle) : base(handle)
{
}
[Export("TextLetterSpacing"), Browsable(true)]
public float TextLetterSpacing
{
get => _textLetterSpacing;
set
{
_textLetterSpacing = value;
SetNeedsDisplay();
}
}
public CustomLabelView()
{
Initialize();
}
public override void AwakeFromNib()
{
// Called when loaded from xib or storyboard.
Initialize();
}
void Initialize()
{
NSRange range = new NSRange(0, Text.Length);
var attributes = AttributedText.GetCoreTextAttributes(0, out range);
var attributedTitle = new NSAttributedString(Text, new CTStringAttributes() { KerningAdjustment = TextLetterSpacing, ForegroundColor = TextColor.CGColor, UnderlineStyle = attributes.UnderlineStyle });
AttributedText = attributedTitle;
SetNeedsDisplay();
}
}
I bind text to this control with language converter
set.Bind(CustomLabelView)
.For(c => c.Text)
.To(vm => vm.TextSource)
.WithConversion("Language", "AgreementText");
and underline property doesn't apply for bound text. Also I tried AttributedText property instead of Text. No any changes.
My LinkerPleaseInclude file contains this lines
public void Include(UILabel label)
{
label.Text = label.Text + "";
label.AttributedText = new NSAttributedString(label.AttributedText.ToString() + "");
}
Any ideas how to sort it out?
I changed the UnderlineStyle property's value to one of the enumeration of CTUnderlineStyle and it works for me.
namespace CoreText
{
//
// Summary:
// Specifies the style of an underline ornament.
//
// Remarks:
// To be added.
public enum CTUnderlineStyle
{
None = 0,
Single = 1,
Thick = 2,
Double = 9
}
}
Here is my code:
void Initialize()
{
this.Text = "This is some formatted text";
NSRange range = new NSRange(0, Text.Length);
var attributes = AttributedText.GetCoreTextAttributes(0, out range);
var attributedTitle = new NSAttributedString(Text, new CTStringAttributes() { KerningAdjustment = TextLetterSpacing, ForegroundColor = TextColor.CGColor, UnderlineStyle = CTUnderlineStyle.Single });
AttributedText = attributedTitle;
SetNeedsDisplay();
}
The underline appears,is this you want?
I just put Initialize method into Draw for my CustomLabel.
Here is the solution:
public override void Draw(CGRect rect)
{
Initialize();
base.Draw(rect);
}
private void Initialize()
{
var attributes = AttributedText.GetCoreTextAttributes(0, out _);
AttributedText = new NSMutableAttributedString(Text,
new CTStringAttributes
{
KerningAdjustment = TextLetterSpacing, Font = attributes.Font,
UnderlineStyle = attributes.UnderlineStyle
});
}
I want to binding a byte[] to difference label in grid view but it is weird when I change the value in a timer event,the onPropertyChanged() don't call,turns out the label didn't update with the byte[].Pls help me out where is the mistake in my code.I can binding a byte with the code I list,but seems not work with byte[].Thanks!
System.Timers.Timer testtimer;
Grid gridView;
byte[] _recvdata;
byte testbyte;
public byte[] RecvData
{
get
{
return _recvdata;
}
set
{
if (_recvdata != value)
{
_recvdata = value;
OnPropertyChanged("RecvData");
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected override void OnPropertyChanged(string propertyName)
{
var changed = PropertyChanged;
if (changed != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
public DevicePage(IDevice currDevice)
{
device = currDevice;
this.Title = "Status";
testtimer = new System.Timers.Timer();
testtimer.Interval = 1000;
testtimer.Elapsed += OnTimedEvent;
testtimer.Enabled = true;
gridView = new Grid();
RecvData = new byte[40];
for (byte i = 0; i < 40;i++)
{
string st;
var lb = new Label ();
st = "RecvData[" + i + "]";
lb.SetBinding(Label.TextProperty, st);
lb.BindingContext = this;
gridView.Children.Add(lb, 0, i);
}
this.Content = gridView;
}
private void OnTimedEvent(object sender, System.Timers.ElapsedEventArgs e)
{
byte i;
testbyte += 1;
for (i = 0; i < 40; i++)
{
RecvData[i] = testbyte;
}
}
The setter of RecvData property is not called when you just change it using [indexer]. You have two options I see:
1) manually call OnPropertyChanged after you change the byte array using indexer:
private void OnTimedEvent(object sender, System.Timers.ElapsedEventArgs e)
{
byte i;
testbyte += 1;
for (i = 0; i < 40; i++)
{
RecvData[i] = testbyte;
}
OnPropertyChanged("RecvData");
}
2) create a wrapper for byte array which would call OnPropertyChanged automatically when you change an array using the indexer:
public class ByteArrayWrapper : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
byte[] _array;
public byte[] Array
{
get
{
return _array;
}
set
{
if (_array != value)
{
_array = value;
OnPropertyChanged("Array");
}
}
}
public byte this[int index]
{
get
{
return _array[index];
}
set
{
_array[index] = value;
OnPropertyChanged("Array");
}
}
protected void OnPropertyChanged(string propertyName)
{
var changed = PropertyChanged;
if (changed != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
then instead of operating on your byte array like this:
public byte[] RecvData
{
// get/set
}
you should use an instance of above class:
public ByteArrayWrapper RecvData
{
// get/set
}
Other code should be just fine. If the binding doesn't work, maybe you'd need to bind to RecvData.Array[i] instead of RecvData[i], please let me know if that works as I'm not able to test right now.
I can successfully work with the badge on my tabbar if i use it straight in my ViewWillAppear function but if i create a function where i try to control it then the badge does not appear.
This is the tabbedpaged renderer where I have to the function that changes the badge.
public override void ViewWillAppear(bool animated)
{
if (TabBar == null) return;
if (TabBar.Items == null) return;
var tabs = Element as TabbedPage;
if (tabs != null)
{
for (int i = 0; i < TabBar.Items.Length; i++)
{
UpdateItem(TabBar.Items[i], tabs.Children[i].Icon);
}
}
base.ViewWillAppear(animated);
}
private void UpdateItem(UITabBarItem item, string icon)
{
TabBar.UnselectedItemTintColor = UIColor.White;
}
public void UpdateBadge ()
{
var tabs = Element as TabbedPage;
if (tabs != null)
{
Device.BeginInvokeOnMainThread(() =>
{
var tab = TabBar.Items[3];
tab.BadgeValue = "New";
tab.BadgeColor = UIColor.Red;
});
}
}
Then I have another file where I handle a pushnotification and this is where I call the UpdateBadgefunction to both push a notification and also update the badge in the app.
void IPush.SendPush()
{
var notification = new UILocalNotification();
notification.SoundName = UILocalNotification.DefaultSoundName;
UIApplication.SharedApplication.PresentLocalNotificationNow(notification);
TabbedPage_Renderer tpr = new TabbedPage_Renderer();
tpr.UpdateBadge();
}
But as stated above this does not add the badge.
If I however add...
var tab = TabBar.Items[3];
tab.BadgeValue = "New";
tab.BadgeColor = UIColor.Red;
...inside the ViewWillAppear straight away it successfully shows an iconbadge when i start the app up but the idea is to control it so i can update the badge whenever i want.
We should not use the instance of the Renderer directly.
If you want to change the UI in the platform's renderer, we can try to define a BindableProperty in the forms. Then tell the renderer do some configuration when this property changed.
Firstly, define a BindableProperty in the page which you want to change its Badge like:
public static readonly BindableProperty BadgeTextProperty = BindableProperty.Create(nameof(BadgeText), typeof(string), typeof(MainPage), "0");
public string BadgeText {
set
{
SetValue(BadgeTextProperty, value);
}
get
{
return (string)GetValue(BadgeTextProperty);
}
}
Secondly, in the renderer, we can set the badge text when this property changed like:
for (int i = 0; i < TabBar.Items.Length; i++)
{
UpdateItem(TabBar.Items[i], tabs.Children[i].Icon);
//register the property changed event
tabs.Children[i].PropertyChanged += TabbarPageRenderer_PropertyChanged;
}
private void TabbarPageRenderer_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
var page = sender as Page;
if (page == null)
return;
if (e.PropertyName == "BadgeText")
{
if (CheckValidTabIndex(page, out int tabIndex))
{
switch(tabIndex)
{
case 0:
UpdateBadge(TabBar.Items[tabIndex], (page as MainPage).BadgeText);
break;
case 1:
//Second Page, you can expand this switch depending on your tabs children
UpdateBadge(TabBar.Items[tabIndex], (page as SecondPage).BadgeText);
break;
default:
break;
}
}
return;
}
}
public bool CheckValidTabIndex(Page page, out int tabIndex)
{
tabIndex = Tabbed.Children.IndexOf(page);
return tabIndex < TabBar.Items.Length;
}
private void UpdateItem(UITabBarItem item, string icon)
{
TabBar.UnselectedItemTintColor = UIColor.White;
...//set the tabItem
}
private void UpdateBadge(UITabBarItem item, string badgeText)
{
item.BadgeValue = text;
item.BadgeColor = UIColor.Red;
}
At last, set the BadgeText in the forms when you want to update the badge.
I want to show datepicker default index value is string but I am not able to do that. Please suggest any idea. Thanks in advance.
I want to show picker like this:
You can use a UITextField and add date picker as a Input vie. And set PlaceHolder as "Date" or any string you want.
Sample Code
UITextField TextInput = new UITextField();
TextInput.Frame = new CGRect(40, 280, View.Frame.Width - 80, 40);
TextInput.Placeholder = "Date";
var picker = new UIDatePicker();
TextInput.InputView = picker;
Here is an example how to do it in ViewCell. You can use similar idea with View
public class TimePickerInCellPage : ContentPage
{
private ListView _listView;
public TimePickerInCellPage()
{
_listView = new ListView
{
RowHeight = 80,
SeparatorColor = Color.Blue,
SeparatorVisibility = SeparatorVisibility.Default
};
_listView.ItemsSource = new List<TaskTime>() {
new TaskTime { Id=1, StartTime=TimeSpan.FromHours(3) } ,
new TaskTime { Id=1, StartTime=TimeSpan.FromHours(5) } ,
new TaskTime { Id=1, StartTime=TimeSpan.FromHours(7) } ,
};
_listView.ItemTemplate = new DataTemplate(typeof(MyCell));
Content = new StackLayout
{
VerticalOptions = LayoutOptions.FillAndExpand,
Children = { _listView }
};
}
}
public class TaskTime
{
public int Id { get; set; }
public string Task { get; set; }
public TimeSpan StartTime { get; set; }
}
class MyCell : ViewCell
{
private readonly DatePicker _myTimePicker;
//private readonly TimePicker _myTimePicker;
public MyCell()
{
//_myTimePicker = new TimePicker()
_myTimePicker = new DatePicker()
{
HorizontalOptions = LayoutOptions.EndAndExpand
};
//_myTimePicker.Format = "HH:mm:ss";
_myTimePicker.Format = "dd:MM:yy HH:mm:ss";
_myTimePicker.SetBinding(TimePicker.TimeProperty, "StartTime");
_myTimePicker.PropertyChanged += MyTimePicker_PropertyChanged;
//_myTimePicker.Focused += _myTimePicker_Focused;
var viewLayout = new StackLayout()
{
HorizontalOptions = LayoutOptions.StartAndExpand,
Orientation = StackOrientation.Horizontal,
Padding = new Thickness(20),
Children = { _myTimePicker }
};
View = viewLayout;
}
bool firstTimeSet; //set when initial binding happens
//private void _myTimePicker_Focused(object sender, FocusEventArgs e)
//{
// firstTimeSet=true;
//}
private void MyTimePicker_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
//if (e.PropertyName == TimePicker.TimeProperty.PropertyName)
if (e.PropertyName == DatePicker.DateProperty.PropertyName)
{
if (!firstTimeSet)
firstTimeSet = true;
else
{
int x = 0;
string s = _myTimePicker.Date.ToString("dd/MM/yy HH:mm:ss");
}
}
}
}
I want to get all entry controls value on button click.
My code is as below - this is how I am adding dynamic control on page:
public BookSeat()
{
ScrollView scroll = new ScrollView();
StackLayout stack = new StackLayout();
int count = Convert.ToInt32(Application.Current.Properties["NoPersonEntry"]);
for (int i = 0; i < count; i++)
{
stack.Children.Add(
new StackLayout()
{
Children = {
new Label (){TextColor = Color.Blue, Text = "First Name: ", WidthRequest = 100,StyleId="FnameLabel"+i },
new Entry() {StyleId="FnameEntry"+i }
}
}
);
}
Button button = new Button
{
Text = "Save"
};
button.Clicked += OnButtonClicked;
stack.Children.Add(button);
scroll.Content = stack;
this.Content = scroll;
}
And below code is for I want to get value on button click
public void OnButtonClicked(object sender, EventArgs e)
{
// Here I want to get value
}
What you can do is to store your entries in a list so that you can access them later on.
For example :
private List<Entry> _myentries = new List<Entry>();
public BookSeat()
{
ScrollView scroll = new ScrollView();
StackLayout stack = new StackLayout();
int count = Convert.ToInt32(Application.Current.Properties["NoPersonEntry"]);
for (int i = 0; i < count; i++)
{
var entry = new Entry() {StyleId="FnameEntry"+i };
_myentries.Add(entry);
stack.Children.Add(
new StackLayout()
{
Children = {
new Label (){TextColor = Color.Blue, Text = "First Name: ", WidthRequest = 100,StyleId="FnameLabel"+i },
entry
}
}
);
}
[...]
}
Now you can do this :
public void OnButtonClicked(object sender, EventArgs e)
{
foreach(var entry in _myentries)
{
var text = entry.Text;//here we go
}
}