將視圖添加到除屏幕上出現的佈局以外的佈局

Question

我使用按鈕的主佈局，當按鈕被觸摸時，它將使用setcontentView切換佈局，並向新查看的佈局添加按鈕。 我得到一個運行時錯誤。

我的代碼：

package com.android.ui; 

import android.app.Activity; 

import android.os.Bundle; 
import android.view.MotionEvent; 
import android.view.View; 
import android.view.View.OnTouchListener; 
import android.widget.Button; 
import android.widget.FrameLayout; 
import android.widget.FrameLayout.LayoutParams; 
import android.widget.ImageView; 

public class mainprog extends Activity implements OnTouchListener { 
    /** Called when the activity is first created. */ 
    private final static int START_DRAGGING = 0; 
    private final static int STOP_DRAGGING = 1; 
    public Button btn1; 
    public Button btn; 
    public FrameLayout layout; 
    private int status; 
    public LayoutParams params; 
    public FrameLayout layout1; 
    public ImageView image; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     layout = (FrameLayout) findViewById(R.id.LinearLayout01); 
     // layout.setOnTouchListener(this); 
     layout1 = (FrameLayout) findViewById(R.id.LinearLayout02); 
     btn1 = (Button) findViewById(R.id.btn1); 
     btn = (Button) findViewById(R.id.btn); 
     btn.setDrawingCacheEnabled(true); 
     btn.setOnTouchListener(this); 
     params = new LayoutParams(LayoutParams.WRAP_CONTENT, 
            LayoutParams.WRAP_CONTENT); 

    } 

    public boolean onTouch(View v, MotionEvent me) { 

     if (me.getAction() == MotionEvent.ACTION_DOWN) { 
      status = START_DRAGGING; 
      image = new ImageView(this); 
      image.setImageBitmap(btn.getDrawingCache()); 
      setContentView(R.layout.draw); 
      layout1.addView(image,params); 

     } 

     return false; 

    } 

} 

我的main.xml

<?xml version="1.0" encoding="utf-8"?> 
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="fill_parent" android:layout_height="fill_parent" 
android:gravity="center" android:id="@+id/LinearLayout01" 
android:paddingLeft="0dip"> 

<Button android:layout_width="wrap_content" 
    android:layout_height="wrap_content" android:id="@+id/btn" 
    android:text="Drag Me" 
    ></Button> 
    </FrameLayout>` 

我draw.xml

<?xml version="1.0" encoding="utf-8"?> 
    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent" 
android:gravity="center" 
android:id="@+id/LinearLayout02" 
android:paddingLeft="0dip" 
> 

<Button 
android:layout_width="wrap_content" 
android:id="@+id/btn1" 
android:layout_height="wrap_content" 
android:text="Drag Meeeeeee" 
></Button> 
</FrameLayout>` 

logcat的

 `I/ActivityManager( 52): Displayed activity com.android.ui/.mainprog: 1156 ms (total 1156 ms) 

D/AndroidRuntime( 260): Shutting down VM 

W/dalvikvm( 260): threadid=3: thread exiting with uncaught exception (group=0x4001b188) 

E/AndroidRuntime( 260): Uncaught handler: thread main exiting due to uncaught exception 

E/AndroidRuntime( 260): java.lang.NullPointerException 

E/AndroidRuntime( 260): at com.android.ui.mainprog.onTouch(mainprog.java:47) 

E/AndroidRuntime( 260): at android.view.View.dispatchTouchEvent(View.java:3705) 

E/AndroidRuntime( 260): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:822) 

E/AndroidRuntime( 260): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:822) 

    E/AndroidRuntime( 260):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:822) 

    E/AndroidRuntime( 260):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:822) 

    E/AndroidRuntime( 260): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1659) 

    E/AndroidRuntime( 260): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107) 

    E/AndroidRuntime( 260): at android.app.Activity.dispatchTouchEvent(Activity.java:2061) 

    E/AndroidRuntime( 260): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643) 

    E/AndroidRuntime( 260): at android.view.ViewRoot.handleMessage(ViewRoot.java:1691) 

    E/AndroidRuntime( 260): at android.os.Handler.dispatchMessage(Handler.java:99) 

    E/AndroidRuntime( 260): at android.os.Looper.loop(Looper.java:123) 

    E/AndroidRuntime( 260): at android.app.ActivityThread.main(ActivityThread.java:4363) 

    E/AndroidRuntime( 260): at java.lang.reflect.Method.invokeNative(Native Method) 

    E/AndroidRuntime( 260): at java.lang.reflect.Method.invoke(Method.java:521) 

    E/AndroidRuntime( 260): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860) 

    E/AndroidRuntime( 260):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 

    E/AndroidRuntime( 260):  at dalvik.system.NativeStart.main(Native Method) 

    I/Process ( 52): Sending signal. PID: 260 SIG: 3 

    I/dalvikvm( 260): threadid=7: reacting to signal 3 

    I/dalvikvm( 260): Wrote stack trace to '/data/anr/traces.txt' 

    I/Process ( 260): Sending signal. PID: 260 SIG: 9 

    I/ActivityManager( 52): Process com.android.ui (pid 260) has died. 

    I/WindowManager( 52): WIN DEATH: Window{43d379c0  com.android.ui/com.android.ui.mainprog paused=false} 

    I/UsageStats( 52): Unexpected resume of com.android.launcher while already resumed in com.android.ui 

    E/gralloc ( 52): [unregister] handle 0x4c23d0 still locked (state=40000001) 

    W/InputManagerService( 52): Got RemoteException sending setActive(false) notification to pid 260 uid 10024 ` 

Answer 1

你的方法來解決這種情況是錯錯在先

setContentView(R.layout.main); 
layout = (FrameLayout) findViewById(R.id.LinearLayout01); 
// layout.setOnTouchListener(this); 
layout1 = (FrameLayout) mistake first 

所以在這裏你對main.xml中設置，這就是爲什麼佈局1將是無效的。

我會建議您使用佈局充氣負載XML佈局視圖對象使用onClickListener按鈕，代替ontouch的

則的onClick方法內和 然後使用該視圖對象呼叫findviewById像obj.findViewById(R.id.LinearLayout01);

然後在那添加圖片，它會解決你的問題。