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在部分内容上滚动RelativeLayout-白色边框

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我有一个相当简单的片段,它将一些彩色的ImageView添加到RelativeLayout . 有比屏幕上可以容纳的图像更多的图像,所以我实现了一些自定义滚动 .

但是,当我滚动时,我看到有一个大约90dp的白色边框重叠内容的一部分,在我滚动之前屏幕的边缘 . 很明显,ImageViews仍在正确创建和绘制,但它们正在被掩盖 .

我怎么摆脱这个?

我试过了:

  • 将RelativeLayout和FrameLayout都更改为WRAP_CONTENT,FILL_PARENT,MATCH_PARENT以及它们的一些组合 .

  • 将两个布局的填充和边距设置为0dp .

例:

分段:

public class MyFrag extends Fragment implements OnTouchListener {
    int currentX;
    int currentY;
    RelativeLayout container;
    final int[] colors = {Color.BLACK, Color.RED, Color.BLUE};

     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup fragContainer, Bundle savedInstanceState) {
         return inflater.inflate(R.layout.fragment_myfrag, null);
     }

     @Override
     public void onActivityCreated(Bundle savedInstanceState) {
         super.onActivityCreated(savedInstanceState);

         container = (RelativeLayout) getView().findViewById(R.id.container);
         container.setOnTouchListener(this);

         // Temp- Add a bunch of images to test scrolling
         for(int i=0; i<1500; i+=100) {
             for (int j=0; j<1500; j+=100) {
                 int color = colors[(i+j)%3];

                 ImageView image = new ImageView(getActivity());
                 image.setScaleType(ImageView.ScaleType.CENTER);
                 image.setBackgroundColor(color);

                 LayoutParams lp = new RelativeLayout.LayoutParams(100, 100);
                 lp.setMargins(i, j, 0, 0); 
                 image.setLayoutParams(lp);

                 container.addView(image);
             }
         }
     }

    @Override 
    public boolean onTouch(View v, MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN: {
                currentX = (int) event.getRawX();
                currentY = (int) event.getRawY();
                break;
            }

            case MotionEvent.ACTION_MOVE: {
                int x2 = (int) event.getRawX();
                int y2 = (int) event.getRawY();
                container.scrollBy(currentX - x2 , currentY - y2);
                currentX = x2;
                currentY = y2;
                break;
            }   
            case MotionEvent.ACTION_UP: {
                break;
            }
        }
        return true; 
    }
}

XML:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    tools:context=".FloorPlanFrag">

    <RelativeLayout 
        android:id="@+id/container" 
        android:layout_width="fill_parent" 
        android:layout_height="fill_parent" />
</FrameLayout>

1 回答

  • 1

    在查看RelativeLayout source时,我注意到 onMeasure() 调用 applyHorizontalSizeRules(LayoutParams childParams, int myWidth)applyVerticalSizeRules(LayoutParams childParams, int myHeight) .

    applyHorizontalSizeRules 我找到了myWidth和myHeight参数:

    // -1 indicated a "soft requirement" in that direction. For example:        
    // left=10, right=-1 means the view must start at 10, but can go as far as it wants to the right
    

    myWidth参数初始化为-1,然后根据onMeasure()参数的MeasureSpec模式进行更改 .

    所以我创建了自己的View,它扩展了RelativeLayout,并覆盖onMeasure()以将模式设置为'unspecified':

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = MeasureSpec.getSize(widthMeasureSpec);
        int height = MeasureSpec.getSize(heightMeasureSpec);
    
        int newWidthSpec = MeasureSpec.makeMeasureSpec(width, MeasureSpec.UNSPECIFIED);
        int newHeightSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.UNSPECIFIED);
    
        super.onMeasure(newWidthSpec, newHeightSpec);
    }
    

    奇迹般有效!

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