如果在WebChromeClient#onCreateWindow的回调中创建了Webview，则Android WebView addJavascriptInterface将不起作用 [英] Android WebView addJavascriptInterface does not work if the webview is created in the callback of WebChromeClient#onCreateWindow
问题描述
以下是我的测试代码.我的问题是，在第二页中，我无法引用 AndroidFunction2 .我正在Nexus 7和Android 4.4上对此进行测试.但是在具有Android 4.0的sumsang i9100上还可以. 我是在做错什么，还是有Android的错误?
The following is my test code. My problem is that in the page two I can not reference AndroidFunction2. I'm testing this on Nexus 7 with Android 4.4. But it's OK on sumsang i9100 with Android 4.0. Am I doing something wrong, or there is an Android's bug?
MainActivity
public class MainActivity extends Activity {
WebView mWebView1;
WebView mWebView2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final FrameLayout mainFrame = (FrameLayout) this.findViewById(R.id.mainFrame);
mWebView1 = new WebView(this);
mWebView1.getSettings().setJavaScriptEnabled(true);
mWebView1.getSettings().setSupportMultipleWindows(true);
mWebView1.setWebViewClient(new WebViewClient() {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
return false;
}
});
mWebView1.setWebChromeClient(new WebChromeClient() {
@Override
public boolean onCreateWindow(WebView view, boolean isDialog,
boolean isUserGesture, Message resultMsg) {
mWebView2 = new WebView(MainActivity.this);
mWebView2.getSettings().setJavaScriptEnabled(true);
mWebView2.getSettings().setSupportMultipleWindows(true);
mWebView2.setWebChromeClient(new WebChromeClient() {
@Override
public void onConsoleMessage(String message, int lineNumber, String sourceID) {
Log.d("WebView", "Line: " + lineNumber + ", " + message);
}
});
mWebView2.addJavascriptInterface(new Object() {
@JavascriptInterface
public void hello2() {
}
}, "AndroidFunction2");
(( WebViewTransport )resultMsg.obj).setWebView(mWebView2);
resultMsg.sendToTarget();
mainFrame.addView(mWebView2);
return true;
}
});
mWebView1.addJavascriptInterface(new Object() {
@JavascriptInterface
public void hello1() {
}
}, "AndroidFunction1");
mWebView1.loadUrl("file:///sdcard/test_1.html");
mainFrame.addView(mWebView1);
}
}
和两个网页
test_1.html :
<html>
<body>
<a href="test_2.html" target="_blank">goto test 2</a>
<div><a href="javascript:alert(typeof AndroidFunction1);"> alert(typeof AndroidFunction1);</a> </div>
<div><a href="javascript:alert(typeof window.AndroidFunction1);"> alert(typeof window.AndroidFunction1);</a> </div>
</body>
</html>
test_2.html
<html>
<body>
<div><a href="javascript:alert(AndroidFunction2);"> alert(AndroidFunction2);</a> </div>
<div><a href="javascript:alert(typeof window.AndroidFunction2);"> alert(typeof window.AndroidFunction2);</a> </div>
</body>
</html>
推荐答案
即使我遇到了同样的问题，在再次浏览文档后，我发现如果将targetSdkVersion设置为17 or higher，则必须添加您想要对JavaScript可用的任何方法的@JavascriptInterface批注(该方法还必须是公共的).
Even I had the same problem and after going through the docs again I found that if you've set your targetSdkVersion to 17 or higher, you must add the @JavascriptInterface annotation to any method that you want available to your JavaScript (the method must also be public).
如果不提供注释，则在Android 4.2或更高版本上运行时，网页将无法访问该方法.
If you do not provide the annotation, the method is not accessible by your web page when running on Android 4.2 or higher.
以下示例(摘自 http://developer.android.com/guide/webapps/webview.html )表明您可以在Android应用程序中包含以下类:
The following example (taken from http://developer.android.com/guide/webapps/webview.html) shows that you can include the following class in your Android application:
public class WebAppInterface {
Context mContext;
/** Instantiate the interface and set the context */
WebAppInterface(Context c) {
mContext = c;
}
@JavascriptInterface // must be added for API 17 or higher
public void showToast(String toast) {
Toast.makeText(mContext, toast, Toast.LENGTH_SHORT).show();
}
}
并绑定为
WebView webView = (WebView) findViewById(R.id.webview);
webView.addJavascriptInterface(new WebAppInterface(this), "Android");
，然后从WebView内的HTML中调用
and then call from the HTML inside the WebView as
<input type="button" value="Say hello" onClick="showAndroidToast('Hello Android!')" />
<script type="text/javascript">
function showAndroidToast(toast) {
Android.showToast(toast);
}
</script>
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