Javascript调用android loadURL（）无法正常工作

Question

我用html和javascript开发了gui。我想在我的webview中加载它并在调用URL时调用javascript函数。我写了以下代码。但我的javascript函数根本没有被调用。我尝试了各种选择。请帮忙。

public class HelloWebView extends Activity {

    WebView webview;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        webview = (WebView) findViewById(R.id.webview);
        webview.getSettings().setJavaScriptEnabled(true);
        webview.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
        webview.getSettings().setPluginState(PluginState.ON);
        webview.getSettings().setDomStorageEnabled(true);
        webview.addJavascriptInterface(new JavaScriptHandler(this), "Android");
        webview.loadUrl("file:///android_asset/index.html");

        webview.setWebViewClient( new WebViewClient() {
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                System.out.println( "shouldOverrideUrlLoading [" + url + "]" );
                webview.loadUrl( "javascript:sendData()" );
                return true;
            }

            public void onPageFinished(WebView view, String url) {
                System.out.println( "onPageFinished [" + url + "]" );
                webview.loadUrl( "javascript:function sendData(){}" );
            }

        });

        webview.setWebChromeClient(new WebChromeClient() { 
            @Override public boolean onJsAlert(WebView view, String url, String message, JsResult result) {
                /* Do whatever you need here */
                return super.onJsAlert(view, url, message, result); 
            } 
        });
    }

    public class JavaScriptHandler {
        Context mContext;

        public JavaScriptHandler(Context context) {
            mContext = context;
        }

        @JavascriptInterface
        public void returnResult() {
        }
    }
}

使用Javascript：

sendData : function()
{
     alert("Inside SendData()");
     if( this.sendQueue.length > 0 )
     {
           var url = this.sendQueue[0];
           this.sendQueue.splice( 0, 1 );
           window.location = url;
      }
 }