I am developing a cross-platform application in C # using Xamarin Forms. I am new to xamarin. I created a portable cross-platform application. In which I try to open local html pages in webview. To call the C # function from javascript, I implemented a hybrid webview using XAMARIN FORUM .
<ContentPage.Content>
<local:HybridWebView x:Name="hybridWebView" Uri="index.html" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" />
</ContentPage.Content>
I call invokeCSharpAction()which is in index.html.
In the Droid project
public class HybridWebViewRenderer : ViewRenderer<HybridWebView, Android.Webkit.WebView>
{
const string JavaScriptFunction = "function invokeCSharpAction(data){jsBridge.invokeAction(data);}";
protected override void OnElementChanged(ElementChangedEventArgs<HybridWebView> e)
{
base.OnElementChanged(e);
Android.Webkit.WebView.SetWebContentsDebuggingEnabled(true);
if (Control == null)
{
var webView = new Android.Webkit.WebView(Forms.Context);
webView.Settings.JavaScriptEnabled = true;
webView.Settings.DomStorageEnabled = true;
Android.Webkit.WebView.SetWebContentsDebuggingEnabled(true);
webView.SetWebChromeClient(new WebChromeClient());
webView.SetWebViewClient(new WebViewClient());
webView.AddJavascriptInterface(new JSBridge(this), "jsBridge");
SetNativeControl(webView);
}
if (e.OldElement != null)
{
Control.RemoveJavascriptInterface("jsBridge");
var hybridWebView = e.OldElement as HybridWebView;
hybridWebView.Cleanup();
}
if (e.NewElement != null)
{
Control.AddJavascriptInterface(new JSBridge(this), "jsBridge");
Control.LoadUrl(string.Format("file:///android_asset/Content/{0}", Element.Uri));
InjectJS(JavaScriptFunction);
}
}
void InjectJS(string script)
{
if (Control != null)
{
Control.LoadUrl(string.Format("javascript: {0}", script));
}
}
}
JSBridge.cs
public class JSBridge : Java.Lang.Object
{
readonly WeakReference<HybridWebViewRenderer> hybridWebViewRenderer;
public JSBridge(HybridWebViewRenderer hybridRenderer)
{
hybridWebViewRenderer = new WeakReference<HybridWebViewRenderer>(hybridRenderer);
}
[JavascriptInterface]
[Export("invokeAction")]
public void InvokeAction(String data)
{
HybridWebViewRenderer hybridRenderer;
if (hybridWebViewRenderer != null && hybridWebViewRenderer.TryGetTarget(out hybridRenderer))
{
hybridRenderer.Element.InvokeAction(data);
}
}
[JavascriptInterface]
[Export("invokeDownloadAction")]
public void invokeDownloadAction(String data)
{
HybridWebViewRenderer hybridRenderer;
if (hybridWebViewRenderer != null && hybridWebViewRenderer.TryGetTarget(out hybridRenderer))
{
hybridRenderer.Element.InvokeAction(data);
}
}
}
Suppose I went to home.html using window.location in index.html Now, if I try to call the same invokeCSharpAction(), the VS output window says
invokeCSharpAction not defined
How can I handle this situation. Can I have an OnNavigated and OnNavigating Event for my hybrid web view?