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我正在构建一个带有 viewpager 水平滑动的应用程序。所有寻呼机组件都可以正常工作，但是我无法播放按钮。代码没有错误，它只是不起作用。谢谢你的帮助。

  package com.test.viewpager;
import android.app.Activity; 
import android.content.Context; 
import android.media.MediaPlayer;
import android.os.Bundle; 
import android.os.Parcelable; 
import android.support.v4.view.PagerAdapter; 
import android.support.v4.view.ViewPager; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;  

public class viewpager extends Activity {   
public MediaPlayer mp = null;
/** Called when the activity is first created. */  


@Override         
public void onCreate(Bundle savedInstanceState) {                 
    super.onCreate(savedInstanceState);                 
    setContentView(R.layout.main);   

    Button btn = (Button) findViewById(R.id.button1);
    OnClickListener listener = new OnClickListener(){
        public void onClick(View v) {
        if (mp == null) {
            mp = MediaPlayer.create(viewpager.this, R.raw.song1);
            mp.start();
            }else {
                mp.stop();
                mp = null;
            }
    }};

    if (btn != null)
        btn.setOnClickListener(listener);


                MyPagerAdapter adapter = new MyPagerAdapter();                 
    ViewPager myPager = (ViewPager) findViewById(R.id.myfivepanelpager);                
    myPager.setAdapter(adapter);                 
    myPager.setCurrentItem(2);         }                  

public void farLeftButtonClick(View v)         {                 
    Toast.makeText(this, "Far Left Button Clicked", Toast.LENGTH_SHORT).show();          
    }         

public void farRightButtonClick(View v)         {                
    Toast.makeText(this, "Far Right Elephant Button Clicked", Toast.LENGTH_SHORT).show();          
    }          
private class MyPagerAdapter extends PagerAdapter {                 
        public int getCount() {                         
            return 5;                 }                  
        public Object instantiateItem(View collection, int position) {                          
            LayoutInflater inflater = (LayoutInflater) collection.getContext()                                         
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);                          
            int resId = 0;                        
            switch (position) {                         
            case 0:                                
                resId = R.layout.page1;                                
                break;                        
                case 1:                                
                    resId = R.layout.page2;                                
                    break;                        
                    case 2:                                
                        resId = R.layout.page3;                               
                        break;                         
                        case 3:                                
                            resId = R.layout.page4;                                
                            break;                         
                            case 4:                                
                                resId = R.layout.page5;                                 
                                break;                         }                          
            View view = inflater.inflate(resId, null);                        
            ((ViewPager) collection).addView(view, 0);                         
            return view;                 }                  
        @Override                
        public void destroyItem(View arg0, int arg1, Object arg2) {                        
            ((ViewPager) arg0).removeView((View) arg2);                  }                 
        @Override                
        public void finishUpdate(View arg0) {                        
            // TODO Auto-generated method stub                 
            }                 
            @Override                
            public boolean isViewFromObject(View arg0, Object arg1) {                        
                return arg0 == ((View) arg1);                  }                 
            @Override                 
            public void restoreState(Parcelable arg0, ClassLoader arg1) {                         
                // TODO Auto-generated method stub                  
                }                  
            @Override                 
            public Parcelable saveState() {                        
                // TODO Auto-generated method stub                         
                return null;                 }                 
            @Override                
            public void startUpdate(View arg0) {                       
                // TODO Auto-generated method stub                 
            }}
    }

这是main.xml

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<android.support.v4.view.ViewPager    
    android:layout_width="match_parent"   
     android:layout_height="match_parent"   
      android:id="@+id/myfivepanelpager"/>


 </LinearLayout>

这是其中一个窗格 page3.xml

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


 <Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/newbutton"
    android:layout_gravity= "center"

   />

4

1 回答 1

1

我无法让我的按钮播放。代码没有错误，只是不起作用

那是因为您试图将按钮作为 Activity 布局 (main.xml) 的一部分进行膨胀。但是，正如您已经从发布的布局中看出的那样：情况并非如此。该按钮是 ViewPager 中显示的“页面”的一部分；因此，将按钮逻辑从 Activity 移动onCreate(...)到 PagerAdapter 中instantiateItem(...)。

这将产生如下内容：

public Object instantiateItem(View collection, int position) {                          
    LayoutInflater inflater = (LayoutInflater) collection.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    // switch/case omitted for simplicity

    View view = inflater.inflate(resId, null);
    Button btn = (Button) findViewById(R.id.button1);
    if (btn != null) btn.setOnClickListener(new View.new OnClickListener(){
        @Override public void onClick(View v) {
            if (mp == null) {
                mp = MediaPlayer.create(viewpager.this, R.raw.song1);
                mp.start();
            } else {
                mp.stop();
                mp = null;
            }
        }
    });

    // add and return view etc.
}
于 2012-10-28T05:11:39.140 回答