android null pointer exception [closed]
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Closed 7 years ago.
Improve this questionI write a simple programm, but there is problem. Here is the code:
package player.org;
import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;
public class Player extends Activity {
/** Called when the activity is first created. */
private MediaPlayer media;
private ProgressBar progress;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.tabs);
progress=(ProgressBar) findViewById(R.id.progress);
progress.setVisibility(ProgressBar.INVISIBLE);
And here is the tabs.xml
<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
android:background="#FFFFFF">
<ProgressBar
android:id="@+id/progress"
android:layout_width="250dp"
android:layout_height="8dp"
style="@android:style/Widget.ProgressBar.Horizontal"
android:layout_x="35dp"
android:layout_y="320dp"/>
</AbsoluteLayout>
But when I run program, it's force closed because of Null pointer exception. Can anyone help?
Here is the LogCat:
08-07 08:24:02.516: ERROR/AndroidRuntime(334): FATAL EXCEPTION: main
08-07 08:24:02.516: ERROR/AndroidRuntime(334): java.lang.RuntimeException: Unable to start activity ComponentInfo{player.org/player.org.Player}: java.lang.NullPointerException
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
08-07 08:24:02.开发者_如何学编程516: ERROR/AndroidRuntime(334): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at android.os.Handler.dispatchMessage(Handler.java:99)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at android.os.Looper.loop(Looper.java:123)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at android.app.ActivityThread.main(ActivityThread.java:3683)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at java.lang.reflect.Method.invokeNative(Native Method)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at java.lang.reflect.Method.invoke(Method.java:507)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at dalvik.system.NativeStart.main(Native Method)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): Caused by: java.lang.NullPointerException
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at player.org.Player.onCreate(Player.java:26)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
08-07 08:24:02.516: ERROR/AndroidRuntime(334): ... 11 more
08-07 08:24:02.536: WARN/ActivityManager(67): Force finishing activity player.org/.Player
08-07 08:24:03.056: WARN/ActivityManager(67): Activity pause timeout for HistoryRecord{4054b008 player.org/.Player}
08-07 08:24:03.167: INFO/ActivityManager(67): Displayed com.android.launcher/com.android.launcher2.Launcher: +37s552ms
08-07 08:24:13.233: WARN/ActivityManager(67): Activity destroy timeout for HistoryRecord{4054b008 player.org/.Player}
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