Question

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的白色边框重叠了内容的一部分，在我滚动之前屏幕边缘的位置。很明显，ImageViews仍在正确创建和绘制，但它们正在被掩盖。

如何摆脱这种情况？

我试过了：

将RelativeLayout和FrameLayout都更改为WRAP_CONTENT，FILL_PARENT，MATCH_PARENT以及这些组合的几种组合。
将两个布局的填充和边距设置为0dp。

例：

片段：

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>

Answer 1

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

在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);
}

像魅力一样！

在部分内容上滚动RelativeLayout-白色边框

1 个答案: