來自網址的Android WebView

Question

我正在嘗試從URL調用網絡並在webview中顯示它。 但是我有一個錯誤。

我已經看到了logcat，但是我仍然沒有得到我的代碼有什么問題。

這是我的XMl代碼

<WebView 
android:id="@+id/adBanner1"
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="1" />

這是我的Java代碼。

private WebView adsbanner;

adsbanner = (WebView) findViewById(R.id.adBanner1);

startWebView("http://www.androidexample.com/media/webview/login.html");

private void startWebView(String url) {
    adsbanner.setWebViewClient(new WebViewClient() {      

        //If you will not use this method url links are opeen in new brower not in webview
        public boolean shouldOverrideUrlLoading(WebView view, String url) {              
            view.loadUrl(url);
            return true;
        }
    });
    adsbanner.getSettings().setJavaScriptEnabled(true);
    adsbanner.loadUrl(url);
}

這是我的logcat

06-25 20:47:04.162: E/AndroidRuntime(2461): FATAL EXCEPTION: main
06-25 20:47:04.162: E/AndroidRuntime(2461): Process: com.indomultimedia.hellobali, PID: 2461
06-25 20:47:04.162: E/AndroidRuntime(2461): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.indomultimedia.hellobali/com.indomultimedia.hellobali.MainHelloballi}: java.lang.NullPointerException
06-25 20:47:04.162: E/AndroidRuntime(2461):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2282)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2340)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at android.app.ActivityThread.access$800(ActivityThread.java:157)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1247)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at android.os.Handler.dispatchMessage(Handler.java:102)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at android.os.Looper.loop(Looper.java:157)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at android.app.ActivityThread.main(ActivityThread.java:5293)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at java.lang.reflect.Method.invokeNative(Native Method)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at java.lang.reflect.Method.invoke(Method.java:515)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1265)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at dalvik.system.NativeStart.main(Native Method)
06-25 20:47:04.162: E/AndroidRuntime(2461): Caused by: java.lang.NullPointerException
06-25 20:47:04.162: E/AndroidRuntime(2461):     at com.indomultimedia.hellobali.MainHelloballi.onCreate(MainHelloballi.java:60)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at android.app.Activity.performCreate(Activity.java:5389)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
06-25 20:47:04.162: E/AndroidRuntime(2461):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2246)
06-25 20:47:04.162: E/AndroidRuntime(2461):     ... 11 more

非常感謝：D

Answer 1

為了使用webview，我們需要在manifestfile中添加權限。 在Androidmanifest.xml文件下添加以下代碼

<manifest xlmns:android...>
 ...
 <uses-permission android:name="android.permission.INTERNET"></uses-permission>
</manifest>

Answer 2

試試這些：

 public class WebPageLoader extends Activity
 {

   final Activity activity = this;
   private String html;
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
      super.onCreate(savedInstanceState);
      this.getWindow().requestFeature(Window.FEATURE_PROGRESS);
      setContentView(R.layout.activity_main);
      WebView webView = (WebView) findViewById(R.id.webview);
      webView.getSettings().setJavaScriptEnabled(true);

webview.loadUrl("http://www.androidexample.com/media/webview/login.html");

       webView.setWebChromeClient(new WebChromeClient() {
        public void onProgressChanged(WebView view, int progress)
        {
            activity.setTitle("Loading...");
            activity.setProgress(progress * 100);

            if(progress == 100)
                activity.setTitle(R.string.app_name);
        }
     });

     webView.setWebViewClient(new WebViewClient() {
        @Override
        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl)
        {

        }

        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url)
        {
            view.loadUrl(url);
            return true;
        }
    });

 }
}