Acivity调用JavaScript

public class MainActivity extends Activity {


private WebView webView;


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
webView = (WebView) findViewById(R.id.webView1);


WebSettings settings = webView.getSettings();
settings.setDefaultTextEncodingName("utf-8");
settings.setJavaScriptEnabled(true);


webView.setWebChromeClient(new WebChromeClient());


webView.loadUrl("file:///android_asset/aa.html");
}

public void tojs(View v) {
// 调用js
webView.loadUrl("javascript:diaoAndroid()");

}

}

布局

<Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="调用js方法" 
        android:onClick="tojs"
        />
    <WebView
        android:id="@+id/webView1"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />