Android音乐播放器fc和错误打开跟踪文件

Question

我最近一直在构建一个音乐应用程序，并且一直使用一些源代码并根据我自己的规范进行定制。我完成编辑和调试，并在启动时暂停。

调试：

Thread [<1> main] (Suspended (exception RuntimeException)) 
ActivityThread.performLaunchActivity(ActivityThread$ActivityClientRecord, Intent) line: 2306  
ActivityThread.handleLaunchActivity(ActivityThread$ActivityClientRecord, Intent) line: 2356 
ActivityThread.access$600(ActivityThread, ActivityThread$ActivityClientRecord, Intent) line: 150  
ActivityThread$H.handleMessage(Message) line: 1244 
ActivityThread$H(Handler).dispatchMessage(Message) line: 99 
Looper.loop() line: 137 
ActivityThread.main(String[]) line: 5195  
Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method] 
Method.invoke(Object, Object...) line: 511 
ZygoteInit$MethodAndArgsCaller.run() line: 795 
ZygoteInit.main(String[]) line: 562 
NativeStart.main(String[]) line: not available [native method] 

Logcat Log（不能似乎得到它在这里展示的）

有人可以看看我的代码，并告诉我在哪里，香港专业教育学院出了错？

这里是我的项目类代码：

​​

Library.java

package com.timmo.tampmusicplayer; 

import java.util.ArrayList; 
import java.util.HashMap; 

import android.app.ListActivity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.ListAdapter; 
import android.widget.ListView; 
import android.widget.SimpleAdapter; 

public class Library extends ListActivity { 
// Songs list 
public ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>(); 

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

    ArrayList<HashMap<String, String>> songsListData = new ArrayList<HashMap<String, String>>(); 

    SongsManager plm = new SongsManager(); 
    // get all songs from sdcard 
    this.songsList = plm.getPlayList(); 

    // looping through playlist 
    for (int i = 0; i < songsList.size(); i++) { 
     // creating new HashMap 
     HashMap<String, String> song = songsList.get(i); 

     // adding HashList to ArrayList 
     songsListData.add(song); 
    } 

    // Adding menuItems to ListView 
    ListAdapter adapter = new SimpleAdapter(this, songsListData, 
      R.layout.playlist_item, new String[] { "songTitle" }, new int[] { 
        R.id.songTitle }); 

    setListAdapter(adapter); 

    // selecting single ListView item 
    ListView lv = getListView(); 
    // listening to single listitem click 
    lv.setOnItemClickListener(new OnItemClickListener() { 

     @Override 
     public void onItemClick(AdapterView<?> parent, View view, 
       int position, long id) { 
      // getting listitem index 
      int songIndex = position; 

      // Starting new intent 
      Intent in = new Intent(getApplicationContext(), 
        NowPlaying.class); 
      // Sending songIndex to PlayerActivity 
      in.putExtra("songIndex", songIndex); 
      setResult(100, in); 
      // Closing PlayListView 
      finish(); 
     } 
    }); 

} 
} 

什么是伟大的，只要你确保你感觉感谢

logcat的

3-22 23:53:21.335: E/AndroidRuntime(25591): FATAL EXCEPTION: main 
03-22 23:53:21.335: E/AndroidRuntime(25591): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.timmo.tampmusicplayer/com.timmo.tampmusicplayer.NowPlaying}: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.ImageButton 
03-22 23:53:21.335: E/AndroidRuntime(25591): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2306) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2356) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at android.app.ActivityThread.access$600(ActivityThread.java:150) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1244) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at android.os.Handler.dispatchMessage(Handler.java:99) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at android.os.Looper.loop(Looper.java:137) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at android.app.ActivityThread.main(ActivityThread.java:5195) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at java.lang.reflect.Method.invokeNative(Native Method) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at java.lang.reflect.Method.invoke(Method.java:511) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at dalvik.system.NativeStart.main(Native Method) 
03-22 23:53:21.335: E/AndroidRuntime(25591): Caused by: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.ImageButton 
03-22 23:53:21.335: E/AndroidRuntime(25591): at com.timmo.tampmusicplayer.NowPlaying.onCreate(NowPlaying.java:54) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at android.app.Activity.performCreate(Activity.java:5104) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080) 
03-22 23:53:21.335: E/AndroidRuntime(25591): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2260) 
03-22 23:53:21.335: E/AndroidRuntime(25591): ... 11 more 

---

Answer 1

您正在将一个对象转换为错误的类型。

03-22 23:53:21.335: E/AndroidRuntime(25591): 
java.lang.RuntimeException: Unable to start activity 
ComponentInfo{com.timmo.tampmusicplayer/com.timmo.tampmusicplayer.NowPlaying}: 
java.lang.ClassCastException: android.widget.Button cannot be cast to 
android.widget.ImageButton 

我将详细说明：您的布局中有一个Button，您试图以ImageButton的形式访问该按钮。