在Activity中创建一个LinearLayout，创建一个scrollHorizon对象(scrollHorizon继承自ViewGroup)，在scrollHorizon中调用createLayout函数来加载myView(继承自View)对象，然后调用deleteAllView函数来删除所有的视图。

scrollHorizon代码：

public class scrollHorizon extends ViewGroup {

private Context context;

public scrollHorizon(Context context) {

super(context);

this.context = context;

createLayout();

deleteAllView();

}

@Override

protected void onLayout(boolean changed, int l, int t, int r, int b) {

int childCount = this.getChildCount();

int childLeft = 0;

int childTop = 0;

for(int i = 0; i < childCount; i++){

View child = getChildAt(i);

child.setVisibility(View.VISIBLE);

child.measure(r - l, b - t);

child.layout(childLeft, childTop, childLeft + child.getMeasuredWidth(),childTop + child.getMeasuredHeight());

if(childLeft <= 320){

childLeft = childLeft + child.getMeasuredWidth();

}

else{

childLeft = 0;

childTop = childTop + child.getMeasuredHeight();

}

}

}

public void createLayout(){

Resources resource = this.getResources();

PackageManager pmanager = context.getPackageManager();

final Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);

mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);

Listlist = pmanager.queryIntentActivities(mainIntent, 0);

for( int i = 0; i < list.size(); i++){

int icon = R.drawable.contacts_button_normal;

LinearLayout linear = new LinearLayout(context);

linear.setLayoutParams(new LayoutParams(45, 45));

linear.setBackgroundDrawable(this.getResources().getDrawable(R.drawable.icon));

ImageView image2 = new ImageView(context);

image2.setBackgroundDrawable(this.getResources().getDrawable(R.drawable.icon));

Drawable drawable = resource.getDrawable(icon);

ImageView image = new ImageView(context);

image.setBackgroundDrawable(drawable);

linear.addView(image2);

linear.addView(image);

this.addView(linear);

}

}

public void deleteAllView(){

int size = this.getChildCount();

for( int i = 0; i < size; i++){

this.removeViewAt(i);

}

}

}

myView代码：

public class myView extends View {

public myView(Context context) {

super(context);

setLayoutParams(new LayoutParams(40,40));

}

}

主Activity代码：

public class scrollHorizonTest extends Activity {

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

LinearLayout linear = new LinearLayout(this);

scrollHorizon horizon = new scrollHorizon(this);

linear.addView(horizon);

this.setContentView(linear);

}

}

显示结果：

如果不调用deleteAllView函数，那程序没有问题，可以正常的进行显示，但调用deleteAllView函数存在空指针异常。

原因为：当你删除掉第一个View后(假设总共有两个View)，当前ViewGroup的子视图只有一个，而这个子视图的位置变为0，所以当你调用removeViewAt(1)时会出现空指针异常，正确的删除方法应该是将deleteAllView函数中的removeViewAt(i)修改为removeViewAt(0);