的WebView在Eclipse上运行

Question

强制关闭我是新到Android，所以请不介意，如果它看起来愚蠢的一些..

HelloWebView.java

package com.website; 

import android.app.Activity; 
import android.os.Bundle; 
import android.webkit.WebView; 
import android.webkit.WebViewClient; 
import android.view.KeyEvent; 

public class HelloWebView extends Activity { 
    WebView webview; 
    /** Called when the activity is first created. */ 
    @Override 
    public boolean onKeyDown(int keyCode, KeyEvent event) { 
     if ((keyCode == KeyEvent.KEYCODE_BACK) && webview.canGoBack()) { 
      webview.goBack(); 
      return true; 
     } 
     return super.onKeyDown(keyCode, event); 
    } 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     webview.setWebViewClient(new HelloWebViewClient()); 
     setContentView(R.layout.main); 
     webview = (WebView) findViewById(R.id.webview); 
     webview.getSettings().setJavaScriptEnabled(true); 
     webview.loadUrl("http://www.google.com"); 
    } 
    private class HelloWebViewClient extends WebViewClient { 
     @Override 
     public boolean shouldOverrideUrlLoading(WebView view, String url) { 
      view.loadUrl(url); 
      return true; 
     } 
    } 
} 

main.xml中

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical"> 

    <WebView 
     android:id="@+id/webview" 
     android:layout_width="fill_parent" 
     android:layout_height="fill_parent" 
    /> 

</LinearLayout> 

Answer 1

您的webview数据成员在第23行中仍未初始化。您不会为第25行分配值。只需将第23行移至第25行（findViewById()调用）之后。