Question

我正在尝试创建自己的列表，因此我正在扩展AdapterView类。我重写了onLayout方法来添加子项，测量它们并调用布局方法。我的问题是onLayout方法被无限调用，每次调用都会重复项目。我已经在互联网上查看并确认我的孩子没有改变（我让每个孩子都返回一个没有动态内容的空视图）。这是我的代码：

protected void onLayout(final boolean changed, final int left, final int top, final int right,
            final int bottom)
    {
        super.onLayout(changed, left, top, right, bottom);
        // If we don't have an adapter yet, do nothing and return
        if(mAdapter == null)
        {
            return;
        }
        fillList();
        positionItems();
    }

fillList（）：

private void fillList()
    {
        int position = 0;
        if(mCurrentList*mNumberItemsPerList > mAdapter.getCount() )
        {
            mCurrentList= 0;
            return ;
        }
        if(mCurrentList < 0)
        {
            double lastList = (double)(mAdapter.getCount()/mNumberItemsPerList);
            mCurrentList= (int) Math.ceil(lastList);
            return ;
        }
        //this.removeAllViewsInLayout();
            while( position+mCurrentList*mNumberItemsPerList < mAdapter.getCount() )
            {


                // Child view
                final View child = mAdapter.getView(position+mCurrentList*mNumberItemsPerList, null, this);
                // Add the child and measure its dimensions to calculate the remaining space
                addAndMeasureChild(child);
                position++;
            }

    }

addAndMeasureChild（）：

private void addAndMeasureChild(View child)
    {
        LayoutParams params = child.getLayoutParams();
        if(params == null)
        {
            params = new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
        }
        //child.setLayoutParams(params);
        addViewInLayout(child,-1, params);
        // measure the dimensions
        child.measure(MeasureSpec.EXACTLY | 250,MeasureSpec.EXACTLY | 250);


    }

positionItems（）：

private void positionItems()
    {
        int left = 0;
        int middleItem = mNumberItemsPerList / 2;
        for(int index =0; index < getChildCount(); index++)
        {
            View child = getChildAt(index);
            int width = child.getMeasuredWidth();
            int height = child.getMeasuredHeight();
            int bottom= (getHeight()-height)/2;
            if(index < middleItem)
            {
                child.layout(left+15, 70+(middleItem-index)*30, left+width, 70+(middleItem-index)*30+height);
            }
            if(index == middleItem)
            {
                child.layout(left+15, 70, left+width, 70+height);
            }
            if(index > middleItem)
            {
                int diff = index -middleItem;
                child.layout(left+15, 70+(middleItem-(index - (middleItem*diff)))*30, left+width, 70+(middleItem-(index - (middleItem*diff)))*30+height);
            }
            left += width;
        }

    }

这是我孩子的getView：

public View getView(final int position, final View convertView, final ViewGroup parent)
    {
        View view = convertView;
        if (view == null) {
            view = LayoutInflater.from(getContext()).inflate(R.layout.cat_item_layout, null);
        }
        return view;
    }

Answer 1

我已经弄明白是什么导致对onLayout的无限调用。在我的主要布局上，我在相对布局中添加了一个带有此自定义视图的时钟。我不知道为什么但是时钟（每秒更新一次）会导致我的视图再次调用onLayout。

AdapterView onLayout无限循环

1 个答案: