eclipse中的Android应用

Question

我已经搜寻了几天，但找不到答案，也许你们可以帮忙。

我正在eclipse中创建一个android应用程序，这一切正常，只是一件事困扰着我。

这是我的main.java：

    package com.test;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Toast;

public class Main extends Activity implements OnClickListener {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

     // Add Click listeners for all buttons
        View firstButton = findViewById(R.id.btn_rassen);
        firstButton.setOnClickListener(this);
        View secondButton = findViewById(R.id.button2);
        secondButton.setOnClickListener(this);
    }

    // Process the button click events
 @Override
 public void onClick(View v) {
  switch(v.getId()){
   case R.id.btn_rassen:
    Intent j = new Intent(this, Webscreen.class);
       j.putExtra(com.test.Webscreen.URL, 
         "http://www.google.com/");

       startActivity(j);

   break; 

   case R.id.button2:
    Intent k = new Intent(this, Webscreen.class);
       k.putExtra(com.test.Webscreen.URL, 
         "http://notworkingurltotest.com");
       startActivity(k);
   break;

  }  
 }
}

现在，当它调用webview.java时，将显示被调用的页面，但不会显示我在布局xml页面中创建的按钮。 有人知道为什么会这样吗？

非常感谢您的帮助！

哦，这是我的webscreen.java

package com.test;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.Window;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;

public class Webscreen extends Activity {

    public static final String URL = "";
    private static final String TAG = "WebscreenClass";
    private WebView webview;
    private ProgressDialog progressDialog;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.webscreen);

        this.getIntent().getExtras(); 
        this.webview = (WebView) findViewById(R.string.webview);


        String turl = getIntent().getStringExtra(URL);
        Log.i(TAG, " URL = "+turl);

    WebView webview = new WebView(this);
    setContentView(webview);


        final Activity activity = this;     

        webview.setWebViewClient(new WebViewClient() {
            public boolean shouldOverrideUrlLoading(WebView view, String url) {              
                view.loadUrl(url);
                return true;
            }


            public void onLoadResource (WebView view, String url) {
                if (progressDialog == null) {
                    progressDialog = new ProgressDialog(activity);
                    progressDialog.setMessage("Bezig met laden...");
                    progressDialog.show();

                }
            }

            public void onPageFinished(WebView view, String url) {
                if (progressDialog.isShowing()) {
                    progressDialog.dismiss();
                    progressDialog = null;


                }
            }


            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {



                Intent myIntent = new Intent();
                myIntent.setClassName("com.test", "com.test.Main");
                startActivity(myIntent); 

                Toast.makeText(activity, "Laden van onderdeel mislukt, probeer het later nog eens! ", Toast.LENGTH_LONG).show();

                progressDialog.show();
            }

            });




        webview.loadUrl(turl);

    }
}

webscreen.xml布局：

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

  <!-- <1> -->
  <LinearLayout android:orientation="horizontal"
    android:layout_width="fill_parent" android:layout_height="wrap_content">

    <EditText android:id="@+id/url" android:layout_height="wrap_content"
      android:layout_width="wrap_content" android:lines="1"
      android:layout_weight="1.0" android:hint="http://"
      android:visibility="visible" />

    <Button android:id="@+id/go_button" android:layout_height="wrap_content"
      android:layout_width="wrap_content" android:text="go_button" />

  </LinearLayout>

  <!-- <2> -->
  <WebView
        android:id="@string/webview"
        android:layout_width="fill_parent" 
        android:layout_height="0dip"

        />
</LinearLayout>

Answer 1

看起来您正在创建第二个Web视图，然后将其设置为内容视图，因此将替换R.layout.webscreen。

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.webscreen);

    this.getIntent().getExtras(); 
    this.webview = (WebView) findViewById(R.string.webview);

    String turl = getIntent().getStringExtra(URL);
    Log.i(TAG, " URL = "+turl);

    **WebView webview = new WebView(this);
    setContentView(webview);**
.....

编辑：

我刚注意到您的代码中有一些内容，该行应为：

this.webview = (WebView) findViewById(R.string.webview);

绝对是：

this.webview = (WebView) findViewById(R.**id**.webview);

编辑2：我在做项目时刚注意到另一件事。 webscreen.xml中的以下内容：

 android:id="@string/webview"

应该：

 android:id="@+id/webview"

编辑3：并在webscreen.xml中注意到另一件事：

android:layout_height="0dip"

确定要高度为0吗？ ;-)