Android infalter 将视图添加到布局

Question

我正在尝试将由背景和移动云组成的视图添加到具有按钮和复选框的布局中。我尝试 getLayoutInflater 将它们合并在一起，但它强制关闭。这是 MainActivity 代码：

public class MainActivity extends Activity{

MyCloud myView;
float x, y;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    myView = new MyCloud(this);
    getWindow().setFormat(PixelFormat.RGBA_8888);
    setContentView(myView);


    View view = getLayoutInflater().inflate(R.layout.activity_main, null, false);

    this.addContentView(view, null);
}
}

这是查看活动：

public class MyCloud extends View{

Bitmap cloud;
int ChangingX;
int ChangingY;
int x, y;

BitmapFactory.Options options;
Bitmap preparedBitmap;

public MyCloud(Context context) {
    // TODO Auto-generated constructor stub
    super(context);

    setFocusable(true);

    options = new BitmapFactory.Options();
    options.inPreferredConfig = Bitmap.Config.ARGB_8888;
    options.inDither = true;
    options.inScaled = false;
    options.inDither = false;
    options.inPurgeable = true;
    preparedBitmap = BitmapFactory.decodeResource(getResources(),
            R.drawable.bg, options);
    Log.d("bitmap", String.valueOf(preparedBitmap));

    cloud = BitmapFactory.decodeResource(getResources(), R.drawable.cloud);

    ChangingX = 50;
    ChangingY = 50;
    x = 0;
    y = 0;
}

@Override
protected void onDraw(Canvas canvas) {
    // TODO Auto-generated method stub
    super.onDraw(canvas);
    canvas.drawBitmap(preparedBitmap, 0, 0, null); // for background
    canvas.drawBitmap(cloud, ChangingX , 50, null); // for cloud 
    if (ChangingX < canvas.getWidth())
        ChangingX += 2;
    else
        ChangingX = 50;

    invalidate();

}

}

布局代码：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/bg"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignParentRight="true"
    android:layout_marginBottom="170dp"
    android:layout_marginRight="58dp"
    android:text="Button" />

<CheckBox
    android:id="@+id/checkBox1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/button1"
    android:layout_alignBottom="@+id/button1"
    android:layout_alignParentLeft="true"
    android:layout_marginLeft="27dp"
    android:text="CheckBox" />

 </RelativeLayout>

我遇到的错误：

06-15 12:34:20.801: E/AndroidRuntime(528): FATAL EXCEPTION: main
06-15 12:34:20.801: E/AndroidRuntime(528): 
java.lang.RuntimeException: Unable to start activity
ComponentInfo{com.cloud/com.cloud.MainActivity}: java.lang.NullPointerException
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.app.ActivityThread.access$2300(ActivityThread.java:125)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.os.Handler.dispatchMessage(Handler.java:99)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.os.Looper.loop(Looper.java:123)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.app.ActivityThread.main(ActivityThread.java:4627)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at java.lang.reflect.Method.invokeNative(Native Method)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at java.lang.reflect.Method.invoke(Method.java:521)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at dalvik.system.NativeStart.main(Native Method)
06-15 12:34:20.801: E/AndroidRuntime(528): Caused by: java.lang.NullPointerException
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.view.ViewGroup$LayoutParams.<init>(ViewGroup.java:3573)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.view.ViewGroup$MarginLayoutParams.<init>(ViewGroup.java:3723)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.widget.FrameLayout$LayoutParams.<init>(FrameLayout.java:487)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at    android.widget.FrameLayout.generateLayoutParams(FrameLayout.java:431)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.view.ViewGroup.addViewInner(ViewGroup.java:1975)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.view.ViewGroup.addView(ViewGroup.java:1865)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.view.ViewGroup.addView(ViewGroup.java:1845)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at com.android.internal.policy.impl.PhoneWindow.addContentView(PhoneWindow.java:229)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.app.Activity.addContentView(Activity.java:1681)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at com.cloud.MainActivity.onCreate(MainActivity.java:35)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
06-15 12:34:20.801: E/AndroidRuntime(528):  
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
06-15 12:34:20.801: E/AndroidRuntime(528):  ... 11 more

现在我以前从未使用过 getLayoutInflater，所以请您耐心等待我并在代码中告诉我如何解决此问题，或者是否有任何其他方法可以将视图添加到布局中。提前致谢

Answer 1

在你的 activity_main.xml 中有一个 LinearLayout 或 Relayout

膨胀activity_main.xml

myView = new MyCloud(this); 
View view = getLayoutInflater().inflate(R.layout.activity_main, null, false);
LinearLayout ll = (LinearLayout) view.findViewById(R.id.ll);
ll.addView(myView); // add custom view to linealayout
setContentView(view); // set the inflated layout to activity

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >

<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignParentRight="true"
    android:layout_marginBottom="170dp"
    android:layout_marginRight="58dp"
    android:text="Button" />

<CheckBox
    android:id="@+id/checkBox1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/button1"
    android:layout_alignBottom="@+id/button1"
    android:layout_alignParentLeft="true"
    android:layout_marginLeft="27dp"
    android:text="CheckBox" />
 <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/ll"
        android:layout_above="@+id/checkBox1"
        android:orientation="vertical"
      />
 </RelativeLayout>

快照

编辑：

另类

你可以拥有

  setContentView(R.layout.activity_main);
  myView = new MyCloud(this);  
  LinearLayout ll = (LinearLayout)findViewById(R.id.ll);
  ll.addView(myView); // add custom view to linealayout  

在你的RelativeLayout

   android:background="@drawable/ic_launcher"