wondering if anyone can help, the text on the webView is too small, I have an HTML that I have NO control over.
How can I increase the size?
I have tried Xamarin forms: Webview content default size is too small
but did not work for me as the page does not load at all.
Is this a bug?
Am I missing something?
Any suggestions
<WebView VerticalOptions="FillAndExpand"
HorizontalOptions="FillAndExpand">
<WebView.Source>
<HtmlWebViewSource
Html="{Binding HtmlSource}" />
</WebView.Source>
</WebView>
using Foundation;
using WebKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;
[assembly: ExportRenderer(typeof(WebView), typeof(MyWebViewRenderer))]
namespace MyCompany
{
public class MyWebViewRenderer : ViewRenderer<WebView, WKWebView>
{
WKWebView wkWebView;
protected override void OnElementChanged(ElementChangedEventArgs<WebView> e)
{
base.OnElementChanged(e);
if (Control != null) return;
var config = new WKWebViewConfiguration();
wkWebView = new WKWebView(Frame, config) {NavigationDelegate = new MyNavigationDelegate()};
SetNativeControl(wkWebView);
}
}
}
public class MyNavigationDelegate : WKNavigationDelegate
{
public override void DidFinishNavigation(WKWebView webView, WKNavigation navigation)
{
string fontSize = "200%";
string stringHtml = string.Format("document.getElementsByTagName('body')[0].style.webkitTextSizeAdjust= '{0}'", fontSize);
WKJavascriptEvaluationResult handler = (NSObject result, NSError err) =>
{
if (err != null)
{
System.Console.WriteLine(err);
}
if (result != null)
{
System.Console.WriteLine(result);
}
};
webView.EvaluateJavaScript(stringHtml, handler);
}
}
The viewport element on a page
<meta name="viewport" content="width=device-width, initial-scale=1.0">
can be set with a renderer (omitting initial-scale):
using Foundation;
using WebKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;
using MyNamespace.iOS.Renderers;
[assembly: ExportRenderer(typeof(WebView), typeof(MyWebViewRenderer))]
namespace MyNamespace.iOS.Renderers
{
//'WebViewRenderer' is obsolete: 'WebViewRenderer is obsolete as of 4.4.0. Please use the WkWebViewRenderer instead'
//WkWebViewRenderer inherits from WKWebView
public class MyWebViewRenderer : WkWebViewRenderer
{
protected override void OnElementChanged(VisualElementChangedEventArgs e)
{
base.OnElementChanged(e);
if (e.NewElement != null)
{
WebView webView = Element as WebView;
webView.VerticalOptions = LayoutOptions.FillAndExpand;
string jScript = #"var meta = document.createElement('meta'); " +
"meta.setAttribute('name', 'viewport');" +
"meta.setAttribute('content', 'width=device-width');" +
"document.getElementsByTagName('head')[0].appendChild(meta);";
//WKUserScriptInjectionTime should be AtDocumentEnd
var userScript = new WKUserScript((NSString)jScript, WKUserScriptInjectionTime.AtDocumentEnd, true);
WKWebView wkWebView = this;
WKWebViewConfiguration wkWebViewConfig = wkWebView.Configuration;
wkWebViewConfig.UserContentController.AddUserScript(userScript);
}
}
}
}
See also "Using the viewport meta tag to control layout on mobile browsers" for a closer description on screen size, pixel scale, device orientation and zoom.
Note:
The meta tag seems to be set as follows in Safari in an iPad/iPhone simulator:
<meta name="viewport" content="width=device-width, initial-scale=1, viewport-fit=cover">
I need to pass a query string into a WebView Xamarin Source on Navigating (www.websiteexmple.com?mobileapp=true).
In Android works perfect, but in IOS does not seems to work correctly sometimes . I am missing someting ?
I have notice it does not work in IOS when Net Core website needs to do some redirects : Ex: User Enter Email and click Next Step.
public void WebView_NavigatingAsync(object sender, WebNavigatingEventArgs args)
{
if (!args.Url.Contains(Source) && !args.Url.Contains("facebook") && !args.Url.Contains("google"))
{
var uri = new Uri(args.Url);
// Device.OpenUri(uri);
Launcher.OpenAsync(uri);
args.Cancel = true;
}
else
{
var src = args.Url;
string prefix = "?";
if (src.Contains("?"))
{
prefix = "&";
}
if (!args.Url.Contains("mobileapp=true"))
{
args.Cancel = true;
var webview = (WebView)sender;
webview.Source = src + prefix + "mobileapp=true";
}
}
}
I think there is a bug in WebView.Source for iOS, the question mark is coming encoded and the system didn't recognize the URL.
You can create a custom WebViewRender and replace %3F to ?
On iOS project create a CustomWebViewRender
[assembly: ExportRenderer(typeof(CustomWebView), typeof(CustomWebViewRenderer))]
namespace Test.iOS.Renders
{
public class CustomWebViewRenderer : WkWebViewRenderer
{
public override WKNavigation LoadRequest (NSUrlRequest request)
{
var url = request.Url.ToString().Replace("html%3F", "html?");
var dotnetURI = new System.Uri(url);
var idn = new System.Globalization.IdnMapping();
NSUrl nsURL = new NSUrl(dotnetURI.Scheme, idn.GetAscii(dotnetURI.DnsSafeHost), dotnetURI.PathAndQuery);
return base.LoadRequest(new NSUrlRequest(nsURL));
}
}
}
On Xamarin project use your custom WebView
cs file:
namespace Test.Renders
{
public class CustomWebView : WebView
{
}
}
Xaml file:
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:test="clr-namespace:Test.Renders"
...>
<ContentPage.Content>
<StackLayout>
<test:CustomWebView x:Name="map"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand"/>
...
Currently working on a project where I want to use AppCompat and have a requirement setting title and subtitle on most of the pages.
It doesn't work using AppCompat at all - neither setting the properties nor using a custom view.
When not using AppCompat both works as expected. The full source code is available here so just run the app if you're curious :)
using System.ComponentModel;
using Android.App;
using Android.Widget;
using App1.Droid.Renderers;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;
#if __APPCOMPAT__
using NavigationRenderer = Xamarin.Forms.Platform.Android.AppCompat.NavigationPageRenderer;
#else
using NavigationRenderer = Xamarin.Forms.Platform.Android.NavigationRenderer;
#endif
[assembly: ExportRenderer(typeof(NavigationPage), typeof(NavigationPageRenderer))]
namespace App1.Droid.Renderers
{
public class NavigationPageRenderer : NavigationRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<NavigationPage> e)
{
base.OnElementChanged(e);
SetCustomView(e.NewElement.CurrentPage.GetType().Name);
}
private void SetCustomView(string view)
{
var activity = (Activity)Context;
#if __APPCOMPAT__
var actionBar = ((FormsAppCompatActivity)Context).SupportActionBar;
#else
var actionBar = activity.ActionBar;
#endif
actionBar.Title = view;
actionBar.Subtitle = " -> " + view;
var abv = new LinearLayout(activity)
{
Orientation = Orientation.Vertical
};
var main = new TextView(activity)
{
Text = view,
};
main.SetTextColor(Color.Aqua.ToAndroid());
main.SetPadding(4, 4, 2, 6);
abv.AddView(main);
abv.AddView(new TextView(activity)
{
Text = " -> " + view
});
actionBar.SetDisplayShowCustomEnabled(true);
actionBar.CustomView = abv;
}
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (e.PropertyName.Equals("CurrentPage"))
{
SetCustomView(((NavigationPage)sender).CurrentPage.GetType().Name);
}
}
}
}
Edit: Thanks #jimmgarr. Altered the code slightly to keep alternating between AppCompbat and "normal mode". The code is available here
So it looks like the NavigationPage uses its own Toolbar instance. That's why setting the properties on SupportActionBar isn't doing anything.
I was able to get it working by overriding OnViewAdded() to get a reference to the new Toolbar when it's added:
public override void OnViewAdded(Android.Views.View child)
{
base.OnViewAdded(child);
if (child.GetType() == typeof(Support.Toolbar))
toolbar = (Support.Toolbar)child;
}
Then using the reference inside SetCustomView() to set only the Subtitle since the Title is already set automatically.
Here's the complete renderer class :)
How do you switch between pages in Xamarin Forms?
My main page is a ContentPage and I don't want to switch to something like a Tabbed Page.
I've been able to pseudo-do it by finding parents of the controls that should trigger the new page until I find the ContentPage and then swap out the Content with controls for a new page. But this seems really sloppy.
In the App class you can set the MainPage to a Navigation Page and set the root page to your ContentPage:
public App ()
{
// The root page of your application
MainPage = new NavigationPage( new FirstContentPage() );
}
Then in your first ContentPage call:
Navigation.PushAsync (new SecondContentPage ());
Xamarin.Forms supports multiple navigation hosts built-in:
NavigationPage, where the next page slide in,
TabbedPage, the one you don't like
CarouselPage, that allows for switching left and right to next/prev pages.
On top of this, all pages also supports PushModalAsync() which just push a new page on top of the existing one.
At the very end, if you want to make sure the user can't get back to the previous page (using a gesture or the back hardware button), you can keep the same Page displayed and replace its Content.
The suggested options of replacing the root page works as well, but you'll have to handle that differently for each platform.
If your project has been set up as a PCL forms project (and very likely as Shared Forms as well but I haven't tried that) there is a class App.cs that looks like this:
public class App
{
public static Page GetMainPage ()
{
AuditorDB.Model.Extensions.AutoTimestamp = true;
return new NavigationPage (new LoginPage ());
}
}
you can modify the GetMainPage method to return a new TabbedPaged or some other page you have defined in the project
From there on you can add commands or event handlers to execute code and do
// to show OtherPage and be able to go back
Navigation.PushAsync(new OtherPage());
// to show AnotherPage and not have a Back button
Navigation.PushModalAsync(new AnotherPage());
// to go back one step on the navigation stack
Navigation.PopAsync();
Push a new page onto the stack, then remove the current page. This results in a switch.
item.Tapped += async (sender, e) => {
await Navigation.PushAsync (new SecondPage ());
Navigation.RemovePage(this);
};
You need to be in a Navigation Page first:
MainPage = NavigationPage(new FirstPage());
Switching content isn't ideal as you have just one big page and one set of page events like OnAppearing ect.
If you do not want to go the previous page i.e. do not let the user go back to the login screen once authorization is done, then you can use;
App.Current.MainPage = new HomePage();
If you want to enable back functionality, just use
Navigation.PushModalAsync(new HomePage())
Seems like this thread is very popular and it will be sad not to mention here that there is an alternative way - ViewModel First Navigation. Most of the MVVM frameworks out there using it, however if you want to understand what it is about, continue reading.
All the official Xamarin.Forms documentation is demonstrating a simple, yet slightly not MVVM pure solution. That is because the Page(View) should know nothing about the ViewModel and vice versa. Here is a great example of this violation:
// C# version
public partial class MyPage : ContentPage
{
public MyPage()
{
InitializeComponent();
// Violation
this.BindingContext = new MyViewModel();
}
}
// XAML version
<?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:viewmodels="clr-namespace:MyApp.ViewModel"
x:Class="MyApp.Views.MyPage">
<ContentPage.BindingContext>
<!-- Violation -->
<viewmodels:MyViewModel />
</ContentPage.BindingContext>
</ContentPage>
If you have a 2 pages application this approach might be good for you. However if you are working on a big enterprise solution you better go with a ViewModel First Navigation approach. It is slightly more complicated but much cleaner approach that allow you to navigate between ViewModels instead of navigation between Pages(Views). One of the advantages beside clear separation of concerns is that you could easily pass parameters to the next ViewModel or execute an async initialization code right after navigation. Now to details.
(I will try to simplify all the code examples as much as possible).
1. First of all we need a place where we could register all our objects and optionally define their lifetime. For this matter we can use an IOC container, you can choose one yourself. In this example I will use Autofac(it is one of the fastest available). We can keep a reference to it in the App so it will be available globally (not a good idea, but needed for simplification):
public class DependencyResolver
{
static IContainer container;
public DependencyResolver(params Module[] modules)
{
var builder = new ContainerBuilder();
if (modules != null)
foreach (var module in modules)
builder.RegisterModule(module);
container = builder.Build();
}
public T Resolve<T>() => container.Resolve<T>();
public object Resolve(Type type) => container.Resolve(type);
}
public partial class App : Application
{
public DependencyResolver DependencyResolver { get; }
// Pass here platform specific dependencies
public App(Module platformIocModule)
{
InitializeComponent();
DependencyResolver = new DependencyResolver(platformIocModule, new IocModule());
MainPage = new WelcomeView();
}
/* The rest of the code ... */
}
2.We will need an object responsible for retrieving a Page (View) for a specific ViewModel and vice versa. The second case might be useful in case of setting the root/main page of the app. For that we should agree on a simple convention that all the ViewModels should be in ViewModels directory and Pages(Views) should be in the Views directory. In other words ViewModels should live in [MyApp].ViewModels namespace and Pages(Views) in [MyApp].Views namespace. In addition to that we should agree that WelcomeView(Page) should have a WelcomeViewModel and etc. Here is a code example of a mapper:
public class TypeMapperService
{
public Type MapViewModelToView(Type viewModelType)
{
var viewName = viewModelType.FullName.Replace("Model", string.Empty);
var viewAssemblyName = GetTypeAssemblyName(viewModelType);
var viewTypeName = GenerateTypeName("{0}, {1}", viewName, viewAssemblyName);
return Type.GetType(viewTypeName);
}
public Type MapViewToViewModel(Type viewType)
{
var viewModelName = viewType.FullName.Replace(".Views.", ".ViewModels.");
var viewModelAssemblyName = GetTypeAssemblyName(viewType);
var viewTypeModelName = GenerateTypeName("{0}Model, {1}", viewModelName, viewModelAssemblyName);
return Type.GetType(viewTypeModelName);
}
string GetTypeAssemblyName(Type type) => type.GetTypeInfo().Assembly.FullName;
string GenerateTypeName(string format, string typeName, string assemblyName) =>
string.Format(CultureInfo.InvariantCulture, format, typeName, assemblyName);
}
3.For the case of setting a root page we will need sort of ViewModelLocator that will set the BindingContext automatically:
public static class ViewModelLocator
{
public static readonly BindableProperty AutoWireViewModelProperty =
BindableProperty.CreateAttached("AutoWireViewModel", typeof(bool), typeof(ViewModelLocator), default(bool), propertyChanged: OnAutoWireViewModelChanged);
public static bool GetAutoWireViewModel(BindableObject bindable) =>
(bool)bindable.GetValue(AutoWireViewModelProperty);
public static void SetAutoWireViewModel(BindableObject bindable, bool value) =>
bindable.SetValue(AutoWireViewModelProperty, value);
static ITypeMapperService mapper = (Application.Current as App).DependencyResolver.Resolve<ITypeMapperService>();
static void OnAutoWireViewModelChanged(BindableObject bindable, object oldValue, object newValue)
{
var view = bindable as Element;
var viewType = view.GetType();
var viewModelType = mapper.MapViewToViewModel(viewType);
var viewModel = (Application.Current as App).DependencyResolver.Resolve(viewModelType);
view.BindingContext = viewModel;
}
}
// Usage example
<?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:viewmodels="clr-namespace:MyApp.ViewModel"
viewmodels:ViewModelLocator.AutoWireViewModel="true"
x:Class="MyApp.Views.MyPage">
</ContentPage>
4.Finally we will need a NavigationService that will support ViewModel First Navigation approach:
public class NavigationService
{
TypeMapperService mapperService { get; }
public NavigationService(TypeMapperService mapperService)
{
this.mapperService = mapperService;
}
protected Page CreatePage(Type viewModelType)
{
Type pageType = mapperService.MapViewModelToView(viewModelType);
if (pageType == null)
{
throw new Exception($"Cannot locate page type for {viewModelType}");
}
return Activator.CreateInstance(pageType) as Page;
}
protected Page GetCurrentPage()
{
var mainPage = Application.Current.MainPage;
if (mainPage is MasterDetailPage)
{
return ((MasterDetailPage)mainPage).Detail;
}
// TabbedPage : MultiPage<Page>
// CarouselPage : MultiPage<ContentPage>
if (mainPage is TabbedPage || mainPage is CarouselPage)
{
return ((MultiPage<Page>)mainPage).CurrentPage;
}
return mainPage;
}
public Task PushAsync(Page page, bool animated = true)
{
var navigationPage = Application.Current.MainPage as NavigationPage;
return navigationPage.PushAsync(page, animated);
}
public Task PopAsync(bool animated = true)
{
var mainPage = Application.Current.MainPage as NavigationPage;
return mainPage.Navigation.PopAsync(animated);
}
public Task PushModalAsync<TViewModel>(object parameter = null, bool animated = true) where TViewModel : BaseViewModel =>
InternalPushModalAsync(typeof(TViewModel), animated, parameter);
public Task PopModalAsync(bool animated = true)
{
var mainPage = GetCurrentPage();
if (mainPage != null)
return mainPage.Navigation.PopModalAsync(animated);
throw new Exception("Current page is null.");
}
async Task InternalPushModalAsync(Type viewModelType, bool animated, object parameter)
{
var page = CreatePage(viewModelType);
var currentNavigationPage = GetCurrentPage();
if (currentNavigationPage != null)
{
await currentNavigationPage.Navigation.PushModalAsync(page, animated);
}
else
{
throw new Exception("Current page is null.");
}
await (page.BindingContext as BaseViewModel).InitializeAsync(parameter);
}
}
As you may see there is a BaseViewModel - abstract base class for all the ViewModels where you can define methods like InitializeAsync that will get executed right after the navigation. And here is an example of navigation:
public class WelcomeViewModel : BaseViewModel
{
public ICommand NewGameCmd { get; }
public ICommand TopScoreCmd { get; }
public ICommand AboutCmd { get; }
public WelcomeViewModel(INavigationService navigation) : base(navigation)
{
NewGameCmd = new Command(async () => await Navigation.PushModalAsync<GameViewModel>());
TopScoreCmd = new Command(async () => await navigation.PushModalAsync<TopScoreViewModel>());
AboutCmd = new Command(async () => await navigation.PushModalAsync<AboutViewModel>());
}
}
As you understand this approach is more complicated, harder to debug and might be confusing. However there are many advantages plus you actually don't have to implement it yourself since most of the MVVM frameworks support it out of the box. The code example that is demonstrated here is available on github. There are plenty of good articles about ViewModel First Navigation approach and there is a free Enterprise Application Patterns using Xamarin.Forms eBook which is explaining this and many other interesting topics in detail.
By using the PushAsync() method you can push and PopModalAsync() you can pop pages to and from the navigation stack. In my code example below I have a Navigation page (Root Page) and from this page I push a content page that is a login page once I am complete with my login page I pop back to the root page
~~~ Navigation can be thought of as a last-in, first-out stack of Page objects.To move from one page to another an application will push a new page onto this stack. To return back to the previous page the application will pop the current page from the stack. This navigation in Xamarin.Forms is handled by the INavigation interface
Xamarin.Forms has a NavigationPage class that implements this interface and will manage the stack of Pages. The NavigationPage class will also add a navigation bar to the top of the screen that displays a title and will also have a platform appropriate Back button that will return to the previous page. The following code shows how to wrap a NavigationPage around the first page in an application:
Reference to content listed above and a link you should review for more information on Xamarin Forms, see the Navigation section:
http://developer.xamarin.com/guides/cross-platform/xamarin-forms/introduction-to-xamarin-forms/
~~~
public class MainActivity : AndroidActivity
{
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
Xamarin.Forms.Forms.Init(this, bundle);
// Set our view from the "main" layout resource
SetPage(BuildView());
}
static Page BuildView()
{
var mainNav = new NavigationPage(new RootPage());
return mainNav;
}
}
public class RootPage : ContentPage
{
async void ShowLoginDialog()
{
var page = new LoginPage();
await Navigation.PushModalAsync(page);
}
}
//Removed code for simplicity only the pop is displayed
private async void AuthenticationResult(bool isValid)
{
await navigation.PopModalAsync();
}
In App.Xaml.Cs:
MainPage = new NavigationPage( new YourPage());
When you wish to navigate from YourPage to the next page you do:
await Navigation.PushAsync(new YourSecondPage());
You can read more about Xamarin Forms navigation here: https://learn.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/navigation/hierarchical
Microsoft has quite good docs on this.
There is also the newer concept of the Shell. It allows for a new way of structuring your application and simplifies navigation in some cases.
Intro: https://devblogs.microsoft.com/xamarin/shell-xamarin-forms-4-0-getting-started/
Video on basics of Shell: https://www.youtube.com/watch?v=0y1bUAcOjZY&t=3112s
Docs: https://learn.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/shell/
Call:
((App)App.Current).ChangeScreen(new Map());
Create this method inside App.xaml.cs:
public void ChangeScreen(Page page)
{
MainPage = page;
}
In Xamarin we have page called NavigationPage. It holds stack of ContentPages.
NavigationPage has method like PushAsync() and PopAsync(). PushAsync add a page at the top of the stack, at that time that page will become the currently active page. PopAsync() method remove the page from the top of the stack.
In App.Xaml.Cs set like.
MainPage = new NavigationPage( new YourPage());
From YourPage you await Navigation.PushAsync(new newPage()); this method will add newPage at the top of the stack. At this time newPage will be currently active page.
One page to another page navigation in Xamarin.forms using Navigation property Below sample code
void addClicked(object sender, EventArgs e)
{
//var createEmp = (Employee)BindingContext;
Employee emp = new Employee();
emp.Address = AddressEntry.Text;
App.Database.SaveItem(emp);
this.Navigation.PushAsync(new EmployeeDetails());
this.Navigation.PushModalAsync(new EmployeeDetails());
}
To navigate one page to another page with in view cell Below code Xamrian.forms
private async void BtnEdit_Clicked1(object sender, EventArgs e)
{
App.Database.GetItem(empid);
await App.Current.MainPage.Navigation.PushModalAsync(new EmployeeRegistration(empid));
}
Example like below
public class OptionsViewCell : ViewCell
{
int empid;
Button btnEdit;
public OptionsViewCell()
{
}
protected override void OnBindingContextChanged()
{
base.OnBindingContextChanged();
if (this.BindingContext == null)
return;
dynamic obj = BindingContext;
empid = Convert.ToInt32(obj.Eid);
var lblname = new Label
{
BackgroundColor = Color.Lime,
Text = obj.Ename,
};
var lblAddress = new Label
{
BackgroundColor = Color.Yellow,
Text = obj.Address,
};
var lblphonenumber = new Label
{
BackgroundColor = Color.Pink,
Text = obj.phonenumber,
};
var lblemail = new Label
{
BackgroundColor = Color.Purple,
Text = obj.email,
};
var lbleid = new Label
{
BackgroundColor = Color.Silver,
Text = (empid).ToString(),
};
//var lbleid = new Label
//{
// BackgroundColor = Color.Silver,
// // HorizontalOptions = LayoutOptions.CenterAndExpand
//};
//lbleid.SetBinding(Label.TextProperty, "Eid");
Button btnDelete = new Button
{
BackgroundColor = Color.Gray,
Text = "Delete",
//WidthRequest = 15,
//HeightRequest = 20,
TextColor = Color.Red,
HorizontalOptions = LayoutOptions.EndAndExpand,
};
btnDelete.Clicked += BtnDelete_Clicked;
//btnDelete.PropertyChanged += BtnDelete_PropertyChanged;
btnEdit = new Button
{
BackgroundColor = Color.Gray,
Text = "Edit",
TextColor = Color.Green,
};
// lbleid.SetBinding(Label.TextProperty, "Eid");
btnEdit.Clicked += BtnEdit_Clicked1; ;
//btnEdit.Clicked += async (s, e) =>{
// await App.Current.MainPage.Navigation.PushModalAsync(new EmployeeRegistration());
//};
View = new StackLayout()
{
Orientation = StackOrientation.Horizontal,
BackgroundColor = Color.White,
Children = { lbleid, lblname, lblAddress, lblemail, lblphonenumber, btnDelete, btnEdit },
};
}
private async void BtnEdit_Clicked1(object sender, EventArgs e)
{
App.Database.GetItem(empid);
await App.Current.MainPage.Navigation.PushModalAsync(new EmployeeRegistration(empid));
}
private void BtnDelete_Clicked(object sender, EventArgs e)
{
// var eid = Convert.ToInt32(empid);
// var item = (Xamarin.Forms.Button)sender;
int eid = empid;
App.Database.DeleteItem(empid);
}
}
After PushAsync use PopAsync (with this) to remove current page.
await Navigation.PushAsync(new YourSecondPage());
this.Navigation.PopAsync(this);
XAML page add this
<ContentPage.ToolbarItems>
<ToolbarItem Text="Next" Order="Primary"
Activated="Handle_Activated"/>
</ContentPage.ToolbarItems>
on the CS page
async void Handle_Activated(object sender, System.EventArgs e)
{
await App.Navigator.PushAsync(new PAGE());
}
I am trying to set styling in PDF generated from iTextSharp.
It seems the SetListSymbol is not working for me whenever I am trying to set Symbol to list items.
Below is the code that I used:
var elements = HTMLWorker.ParseToList(overviewReader,null);
foreach (var element in elements)
{
//element
var list = element as List;
if (list != null)
{
//list.Symbol.GetImage();
list.SetListSymbol("\u25A0");
list.IndentationLeft = 20f;
doc.Add(list);
}
else
{
doc.Add(element);
}
}
The HTMLWorker within iText and iTextSharp supports some very limited "stylesheets" via iTextSharp.text.html.simpleparser.StyleSheet. These stylesheets are loosely based on HTML/CSS properties but only the most basic (think HTML 3.2).
The three main things that you want to do are (1) load a font, (2) create a StyleSheet pointing to that font and (3) bind the StyleSheet to the HTMLWorker. I'm going to partially lift some code from my answer here.
iTextSharp doesn't automatically spider the entire system looking for fonts so you need to manually register them. (Actually, there is a method that you can call and tell iTextSharp to guess at loading fonts but this is much faster.)
Step #1, load the font, in this case Curlz
//Path to our font
string OurFont = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Fonts), "CURLZ___.TTF");
//Register the font with iTextSharp
iTextSharp.text.FontFactory.Register(OurFont);
Step #2, create a StyleSheet and point it to our font. I'll also set some other properties just to show them off.
//Create a new stylesheet
iTextSharp.text.html.simpleparser.StyleSheet ST = new iTextSharp.text.html.simpleparser.StyleSheet();
//Set the default body font to our registered font's internal name
ST.LoadTagStyle(iTextSharp.text.html.HtmlTags.LI, iTextSharp.text.html.HtmlTags.FACE, "Curlz MT");
ST.LoadTagStyle(iTextSharp.text.html.HtmlTags.LI, iTextSharp.text.html.HtmlTags.COLOR, "FF0000");
ST.LoadTagStyle(iTextSharp.text.html.HtmlTags.LI, iTextSharp.text.html.HtmlTags.SIZE, "50");
Step #3, bind the StyleSheet to our HTMLWorker
//Use our StyleSheet from above when parsing
var elements = HTMLWorker.ParseToList(overviewReader, ST);
Below is a full-working C# WinForms app targeting iTextSharp 5.2.0 that shows off all of the above.
using System;
using System.IO;
using System.Windows.Forms;
using iTextSharp.text;
using iTextSharp.text.html.simpleparser;
using iTextSharp.text.pdf;
namespace WindowsFormsApplication2 {
public partial class Form1 : Form {
public Form1() {
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e) {
//Path to our font
string FontArial = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Fonts), "CURLZ___.TTF");
//Register the font with iTextSharp
iTextSharp.text.FontFactory.Register(FontArial);
//Create a new stylesheet
iTextSharp.text.html.simpleparser.StyleSheet ST = new iTextSharp.text.html.simpleparser.StyleSheet();
//Set the default body font to our registered font's internal name
ST.LoadTagStyle(iTextSharp.text.html.HtmlTags.LI, iTextSharp.text.html.HtmlTags.FACE, "Curlz MT");
ST.LoadTagStyle(iTextSharp.text.html.HtmlTags.LI, iTextSharp.text.html.HtmlTags.COLOR, "FF0000");
ST.LoadTagStyle(iTextSharp.text.html.HtmlTags.LI, iTextSharp.text.html.HtmlTags.SIZE, "50");
//Sample HTML
var html = #"<ul><li>Test</li></ul>";
//File to output
var outputFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "Test.pdf");
//Basic PDF creation, nothing special here
using (FileStream fs = new FileStream(outputFile, FileMode.Create, FileAccess.Write, FileShare.None)) {
using (Document doc = new Document(PageSize.LETTER)) {
using (PdfWriter writer = PdfWriter.GetInstance(doc, fs)) {
doc.Open();
//Bind a reader to our HTML
using (StringReader overviewReader = new StringReader(html)) {
//Use our StyleSheet from above when parsing
var elements = HTMLWorker.ParseToList(overviewReader, ST);
//Loop through each element
foreach (var element in elements) {
//See if the element is a list item
var list = element as List;
if (list != null) {
//Set some properties
list.SetListSymbol("\u25A0");
list.IndentationLeft = 20f;
}
//Add the element to the document
doc.Add(element);
}
}
doc.Close();
}
}
}
this.Close();
}
}
}
List objects = HTMLWorker.ParseToList(new StringReader(format), null);
foreach (IElement element in objects)
{
List list = new List();
list.SetListSymbol("\u2022");
list.IndentationLeft = 20f;
list.Add(element);
if (list.Chunks.Count == 0)
{
doc1.Add(element);
}
else
{
doc1.Add(list);
}
}