I've been trying to find an answer surfing the Internet, but found nothing.So here is my question: I've found an interesting tutorial how to develop your own simple player on android here and started integrating that code into my program, but faced a problem with the Views. I can't even understand why it appears: I've tried inserting ListView everywhere, but nothing happened. So here is my code:EasyFlippingActivity.javapackage 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); }}main.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
rientation="vertical" > <ImageView android:id="@+id/imageView1" android:layout_width="fill_parent" android:layout_height="80dp" android:src="http://stackoverflow.com/questions/11276896/@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="http://stackoverflow.com/questions/11276896/@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="http://stackoverflow.com/questions/11276896/@drawable/songstext" /> </RelativeLayout> </LinearLayout> <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" androidrientation="vertical" android
adding="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.javapackage 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"/>And Error Log:06-30 18:54:56.314: D/dalvikvm(189): GC freed 735 objects / 55256 bytes in 70ms06-30 18:54:56.354: D/AndroidRuntime(189): Shutting down VM06-30 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 exception06-30 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 more06-30 18:54:56.384: I/dalvikvm(189): threadid=7: reacting to signal 306-30 18:54:56.384: E/dalvikvm(189): Unable to open stack trace file '/data/anr/traces.txt': Permission denied06-30 18:58:28.214: I/Process(189): Sending signal. PID: 189 SIG: 9I will be very grateful, if anybody help me. Thank you in advance!
rientation="vertical" > <ImageView android:id="@+id/imageView1" android:layout_width="fill_parent" android:layout_height="80dp" android:src="http://stackoverflow.com/questions/11276896/@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="http://stackoverflow.com/questions/11276896/@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="http://stackoverflow.com/questions/11276896/@drawable/songstext" /> </RelativeLayout> </LinearLayout> <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" androidrientation="vertical" androidadding="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.javapackage 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"/>And Error Log:06-30 18:54:56.314: D/dalvikvm(189): GC freed 735 objects / 55256 bytes in 70ms06-30 18:54:56.354: D/AndroidRuntime(189): Shutting down VM06-30 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 exception06-30 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 more06-30 18:54:56.384: I/dalvikvm(189): threadid=7: reacting to signal 306-30 18:54:56.384: E/dalvikvm(189): Unable to open stack trace file '/data/anr/traces.txt': Permission denied06-30 18:58:28.214: I/Process(189): Sending signal. PID: 189 SIG: 9I will be very grateful, if anybody help me. Thank you in advance!