我一直试图在网上寻找答案，但一无所获。
所以这是我的问题：我在这里找到了一个有趣的教程，如何在 android 上开发自己的简单播放器，并开始将该代码集成到我的程序中，但遇到了视图问题。我什至无法理解它出现的原因：我尝试在任何地方插入 ListView，但什么也没发生。所以这是我的代码：
EasyFlippingActivity.java
package my.easyflipping;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
import android.app.ListActivity;
import android.os.Bundle;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ViewFlipper;
public class EasyflippingActivity extends ListActivity {
private ViewFlipper flipper;
private static final String MEDIA_PATH = new String("/sdcard/");
private List<String> songs = new ArrayList<String>();
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
this.flipper = (ViewFlipper)findViewById(R.id.flipper);
Button groups;
(groups = (Button)findViewById(R.id.groups)).setBackgroundDrawable(this.getResources().getDrawable(R.drawable.group));
Button songs;
(songs = (Button)findViewById(R.id.songs)).setBackgroundDrawable(this.getResources().getDrawable(R.drawable.songs));
groups.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
im_going_left();
flipper.showNext();
groups_func();
}
});
songs.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
update_song_list();
im_going_right();
flipper.showNext();
songs_func();
}
});
}
public void update_song_list() {
File home = new File(MEDIA_PATH);
if (home.listFiles(new Mp3Filter()).length > 0) {
for (File file : home.listFiles(new Mp3Filter())) {
songs.add(file.getName());
}
ArrayAdapter<String> songList = new ArrayAdapter<String>(this,
R.layout.song_item, songs);
setListAdapter(songList);
}
}
public void songs_func ()
{
Button back;
back = (Button)findViewById(R.id.back);
back.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
im_going_left();
flipper.showPrevious();
return;
}
});
}
public void groups_func()
{
Button back;
back = (Button)findViewById(R.id.back);
back.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
im_going_right();
flipper.showPrevious();
return;
}
});
}
public void im_going_right()
{
Animation s_in = AnimationUtils.loadAnimation(this, R.layout.slideinleft);
Animation s_out = AnimationUtils.loadAnimation(this, R.layout.slideoutright);
this.flipper.setInAnimation(s_in);
this.flipper.setOutAnimation(s_out);
}
public void im_going_left()
{
Animation s_in = AnimationUtils.loadAnimation(this, R.layout.slidein);
Animation s_out = AnimationUtils.loadAnimation(this, R.layout.slideout);
this.flipper.setInAnimation(s_in);
this.flipper.setOutAnimation(s_out);
}
}
主要的.xml
<?xml version="1.0" encoding="utf-8"?>
<ViewFlipper xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/flipper"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<ImageView
android:id="@+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="80dp"
android:src="@drawable/phones" />
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="400dp" >
<Button
android:id="@+id/groups"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="45dp"
android:text="" />
<Button
android:id="@+id/songs"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_marginRight="45dp"
android:text="" />
<ImageView
android:id="@+id/imageView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/groups"
android:layout_below="@+id/groups"
android:src="@drawable/groupstext" />
<ImageView
android:id="@+id/imageView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/imageView2"
android:layout_alignRight="@+id/songs"
android:src="@drawable/songstext" />
</RelativeLayout>
</LinearLayout>
<LinearLayout android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="20dip"
android:layout_gravity="top"
android:layout_marginTop="50dip">
<ListView android:id="@+id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:drawSelectorOnTop="false"/>
<TextView android:id="@+id/empty"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="No songs found on SD Card."/>
<Button
android:id="@+id/back"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="45dp"
android:text="back" />
</LinearLayout>
</ViewFlipper>
Mp3Filter.java
package my.easyflipping;
import java.io.File;
import java.io.FilenameFilter;
public class Mp3Filter implements FilenameFilter {
public boolean accept(File arg0, String name) {
return (name.endsWith(".mp3"));
}
}
song_item.xml
<?xml version="1.0" encoding="utf-8"?>
<TextView android:id="@+id/text1" xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
和错误日志：
06-30 18:54:56.314: D/dalvikvm(189): GC freed 735 objects / 55256 bytes in 70ms
06-30 18:54:56.354: D/AndroidRuntime(189): Shutting down VM
06-30 18:54:56.354: W/dalvikvm(189): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
06-30 18:54:56.354: E/AndroidRuntime(189): Uncaught handler: thread main exiting due to uncaught exception
06-30 18:54:56.364: E/AndroidRuntime(189): java.lang.RuntimeException: Unable to start activity ComponentInfo{my.easyflipping/my.easyflipping.EasyflippingActivity}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
06-30 18:54:56.364: E/AndroidRuntime(189): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
06-30 18:54:56.364: E/AndroidRuntime(189): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
06-30 18:54:56.364: E/AndroidRuntime(189): at android.app.ActivityThread.access$2200(ActivityThread.java:119)
06-30 18:54:56.364: E/AndroidRuntime(189): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
06-30 18:54:56.364: E/AndroidRuntime(189): at android.os.Handler.dispatchMessage(Handler.java:99)
06-30 18:54:56.364: E/AndroidRuntime(189): at android.os.Looper.loop(Looper.java:123)
06-30 18:54:56.364: E/AndroidRuntime(189): at android.app.ActivityThread.main(ActivityThread.java:4363)
06-30 18:54:56.364: E/AndroidRuntime(189): at java.lang.reflect.Method.invokeNative(Native Method)
06-30 18:54:56.364: E/AndroidRuntime(189): at java.lang.reflect.Method.invoke(Method.java:521)
06-30 18:54:56.364: E/AndroidRuntime(189): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
06-30 18:54:56.364: E/AndroidRuntime(189): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
06-30 18:54:56.364: E/AndroidRuntime(189): at dalvik.system.NativeStart.main(Native Method)
06-30 18:54:56.364: E/AndroidRuntime(189): Caused by: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
06-30 18:54:56.364: E/AndroidRuntime(189): at android.app.ListActivity.onContentChanged(ListActivity.java:236)
06-30 18:54:56.364: E/AndroidRuntime(189): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:201)
06-30 18:54:56.364: E/AndroidRuntime(189): at android.app.Activity.setContentView(Activity.java:1622)
06-30 18:54:56.364: E/AndroidRuntime(189): at my.easyflipping.EasyflippingActivity.onCreate(EasyflippingActivity.java:26)
06-30 18:54:56.364: E/AndroidRuntime(189): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
06-30 18:54:56.364: E/AndroidRuntime(189): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
06-30 18:54:56.364: E/AndroidRuntime(189): ... 11 more
06-30 18:54:56.384: I/dalvikvm(189): threadid=7: reacting to signal 3
06-30 18:54:56.384: E/dalvikvm(189): Unable to open stack trace file '/data/anr/traces.txt': Permission denied
06-30 18:58:28.214: I/Process(189): Sending signal. PID: 189 SIG: 9
如果有人帮助我，我将不胜感激。先感谢您！