Horizo​​ntalScrollView 只能托管一个直接子级？

Question

我基本上是在这个网站上：http://blog.velir.com/index.php/2010/11/17/android-snapping-horizontal-scroll/

但是我遇到了这个问题：

原因：java.lang.IllegalStateException：Horizo​​ntalScrollView 只能承载一个直接子级"

在这一行：

addView(internalWrapper);

这里是 myHorizo​​ntalScrollView 类：

public class MyHorizontalScrollView extends HorizontalScrollView {

int scrollToViewPos = 0;

public MyHorizontalScrollView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    init(context);
}

public MyHorizontalScrollView(Context context, AttributeSet attrs) {
    super(context, attrs);
    init(context);
}

public MyHorizontalScrollView(Context context) {
    super(context);
    init(context);
}

void init(Context context) {
    // remove the fading as the HSV looks better without it
    setHorizontalFadingEdgeEnabled(false);
    setVerticalFadingEdgeEnabled(false);
}

public void initViews(final MyHorizontalScrollView me, View[] children, int scrollToViewIdx, SizeCallback sizeCallback) {

    LinearLayout internalWrapper = new LinearLayout(getContext());
    internalWrapper.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
    internalWrapper.setOrientation(LinearLayout.HORIZONTAL);
    addView(internalWrapper); 

    final int w = me.getMeasuredWidth();
    final int h = me.getMeasuredHeight();

    sizeCallback.onGlobalLayout();

    int[] dims = new int[2];
    scrollToViewPos = 0;
    for (int i = 0; i < children.length; i++) {
        sizeCallback.getViewSize(i, w, h, dims);
        internalWrapper.addView(children[i], dims[0], dims[1]);
        if (i < scrollToViewIdx) {
            scrollToViewPos += dims[0];
        }
    }

    new Handler().post(new Runnable() {
        public void run() {
            me.scrollBy(scrollToViewPos, 0);
        }
    });

}

@Override
public boolean onTouchEvent(MotionEvent ev) {
    // Allow touch events.      
    return true;
}

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    // Allow touch events.
    return true;
}

public interface SizeCallback {        
    public void onGlobalLayout();
    public void getViewSize(int idx, int w, int h, int[] dims);
}
}

xml 中的 MyHorizo​​ntalScrollView：

<?xml version="1.0" encoding="utf-8"?>
<com.yahya.LeftSlideMenu.MyHorizontalScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_margin="0px"
android:fadingEdge="none"
android:fadingEdgeLength="0px"
android:padding="0px"
android:scrollbars="none" >

<LinearLayout
    android:id="@+id/top"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_margin="0px"
    android:background="#ffffffff"
    android:orientation="horizontal"
    android:padding="0px" >
</LinearLayout>

</com.yahya.LeftSlideMenu.MyHorizontalScrollView>

Answer 1

您缺少addView(internalWrapper);，这就是不可见的原因。