From this great explanation about the differences between WebViewClient
and WebChromeClient
it seems that if you use one, you shouldn't be using the other (for the same WebView object).
Is my understanding correct?
If not, when would one use both WebViewClient
and WebChromeClient
for the same WebView
object?
Is there an example of a situation where only use both WebViewClient
and WebChromeClient
for the same WebView
object would accomplish a certain goal?
You certainly can use both, they just have different functions. Setting your own custom WebViewClient lets you handle onPageFinished, shouldOverrideUrlLoading, etc., WebChromeClient lets you handle Javascript's alert() and other functions.
Just make your own class, for example:
public class MyWebChromeClient extends WebChromeClient {
//Handle javascript alerts:
@Override
public boolean onJsAlert(WebView view, String url, String message, final android.webkit.JsResult result)
{
Log.d("alert", message);
Toast.makeText(context, message, 3000).show();
result.confirm();
return true;
};
...
and / or
public class MyWebViewClient extends WebViewClient {
@Override
//Run script on every page, similar to Greasemonkey:
public void onPageFinished(WebView view, String url) {
view.loadUrl("javascript:alert('hi')");
}
...
Just override the functions described in the documentation, then set your client in onCreate with:
webview.setWebViewClient(new MyWebViewClient());
webview.setWebChromeClient(new MyWebChromeClient());
You can use both clients simultaneously. It is useful as both of them provides different functionalities.
For example, if you would like to:
- follow redirects in web view rather than opening available browser
and
- trace the loading progress
which are impossible with just one of the clients you can do the following:
WebView webView = (WebView) findViewById(R.id.web_view);
webView.setWebViewClient(new WebViewClient());
webView.setWebChromeClient(new WebChromeClient() {
@Override
public void onProgressChanged(WebView view, int newProgress) {
super.onProgressChanged(view, newProgress);
// Your custom code.
}
});
As the default implementation of shouldOverrideUrlLoading(WebView, String) method can be use as-is for above mentioned case - there is no need to override it unless you would like other behavior.
来源:https://stackoverflow.com/questions/6474768/are-webviewclient-and-webchromeclient-mutually-exclusive