應用程序保持強制關閉？

Question

嘿傢伙我仍然是一個小菜，但今天我完成了我的主菜單XML的佈局。我有三個圖像按鈕，並試圖讓一個人去推動另一個XML佈局，所以我在YouTube上觀看了一個關於它的視頻，現在我的應用程序保持強制關閉。在eclipse中沒有錯誤出現，所以我認爲它可能是錯誤的活動名稱或其他東西。

DragonFruitActivity.java

package com.Dragon_Fruit; 

import android.app.Activity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.view.View; 
import android.view.Window; 
import android.view.WindowManager; 
import android.widget.Button; 

public class DragonFruitActivity extends Activity { 
    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     requestWindowFeature(Window.FEATURE_NO_TITLE); 
     getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
       WindowManager.LayoutParams.FLAG_FULLSCREEN); 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     Button playbutton = (Button) findViewById(R.id.playbutton); 
     playbutton.setOnClickListener(new View.OnClickListener() { 

    @Override 
    public void onClick(View arg0) { 
     // TODO Auto-generated method stub 
     startActivity(new Intent("com.Dragon_Fruit.playbutton")); 
    } 
}); 

    } 

}

playbutton.java

package com.Dragon_Fruit; 

import android.app.Activity; 
import android.os.Bundle; 

public class playbutton extends Activity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     // TODO Auto-generated method stub 
     super.onCreate(savedInstanceState); 
    setContentView(R.layout.playscreen); 
    } 

} 

main.xml中

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:gravity="center_horizontal" 
    android:background="@drawable/mainbackground" 
    android:weightSum="1" 
    android:baselineAligned="false" android:orientation="vertical"> 

    <ImageButton 
    android:layout_width="wrap_content" 
    android:background="@drawable/playbutton" 
    android:layout_height="wrap_content" 
    android:src="@drawable/playbutton" 
    android:layout_gravity="center_horizontal" 
    android:id="@+id/playbutton"> 
    </ImageButton> 


    <ImageButton 
    android:layout_width="wrap_content" 
    android:id="@+id/imageButton1" 
    android:background="@drawable/playbutton" 
    android:layout_height="wrap_content" 
    android:src="@drawable/settingsbutton" 
    android:layout_gravity="center_horizontal"> 
    </ImageButton> 

    <ImageButton 
    android:layout_width="wrap_content" 
    android:id="@+id/imageButton1" 
    android:background="@drawable/playbutton" 
    android:layout_height="wrap_content" 
    android:src="@drawable/creditsbutton" android:layout_gravity="center_horizontal"> 
    </ImageButton> 
</LinearLayout> 

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
     package="com.Dragon_Fruit" 
     android:versionCode="1" 
     android:versionName="1.0" 
     android:installLocation="preferExternal"> 


    <application android:icon="@drawable/icon" 
       android:label="@string/app_name" 
       android:debuggable="true"> 

     <activity android:name=".DragonFruitActivity" 
        android:label="@string/app_name" 
        android:screenOrientation="landscape" 
        android:configChanges="keyboard|keyboardHidden|orientation"> 
      <intent-filter> 
       <action android:name="android.intent.action.MAIN" /> 
       <category android:name="android.intent.category.LAUNCHER" /> 
      </intent-filter> 
     </activity> 

<activity android:name=".playbutton" 
        android:label="@string/app_name" 
        > 
      <intent-filter> 
       <action android:name="com.Dragon_Fruit.PLAYBUTTON" /> 
       <category android:name="android.intent.category.DEFAULT" /> 
      </intent-filter> 
     </activity> 

    </application> 
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> 
    <uses-permission android:name="android.permission.WAKE_LOCK"/> 
    <uses-sdk android:minSdkVersion="3" android:targetSdkVersion="9"/> 
    </manifest> 

這裏是logcat的說什麼：

08-03 16:24:26.974: ERROR/AndroidRuntime(3910): FATAL EXCEPTION: main 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.Dragon_Fruit/com.Dragon_Fruit.DragonFruitActivity}: java.lang.ClassCastException: android.widget.ImageButton 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2737) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2753) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at android.app.ActivityThread.access$2500(ActivityThread.java:129) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2107) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at android.os.Handler.dispatchMessage(Handler.java:99) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at android.os.Looper.loop(Looper.java:143) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at android.app.ActivityThread.main(ActivityThread.java:4701) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at java.lang.reflect.Method.invokeNative(Native Method) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at java.lang.reflect.Method.invoke(Method.java:521) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at dalvik.system.NativeStart.main(Native Method) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910): Caused by: java.lang.ClassCastException: android.widget.ImageButton 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at com.Dragon_Fruit.DragonFruitActivity.onCreate(DragonFruitActivity.java:21) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
08-03 16:24:26.974: ERROR/AndroidRuntime(3910):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2701) 

Answer 1

你 可能 有ClassCastException。您ImageButton不延長Button，但ImageView但你嘗試將其轉換爲Button：

<ImageButton 
android:layout_width="wrap_content" 
android:background="@drawable/playbutton" 
android:layout_height="wrap_content" 
android:src="@drawable/playbutton" 
android:layout_gravity="center_horizontal" 
android:id="@+id/playbutton"> 
</ImageButton> 

而且

Button playbutton = (Button) findViewById(R.id.playbutton); 

您應將其更改爲：

ImageButton playbutton = (ImageButton) findViewById(R.id.playbutton); 
playbutton.setOnClickListener(new View.OnClickListener() { 

    @Override 
    public void onClick(View arg0) { 
     // TODO Auto-generated method stub 
     startActivity(new Intent("com.Dragon_Fruit.playbutton")); 
    } 
}