Question

因此，对于练习，我正在学习如何以编程方式创建视图。我创建了一个扩展Viewgroup的新布局（我称之为Custom1），它将子视图（所有大小相同）放在两列中。

这个组的孩子也是一个自定义布局（我称之为Custom2），其中包含一个imageview和两个textview。我使用for循环向视图组添加必要数量的视图，并覆盖onLayout。

现在，我试图在Nexus 4上使用＆＃34; show layout bounds＆＃34;选项已选中。我可以看到Custom1的子项的边界都在正确的位置，并且基于日志，custom2的子项也在正确的位置。但是，只有第一个＆＃34; custom2＆＃34;正确显示（即第一个custom2显示一个imageView和两个textview，其余为空）。

父视图是否可能掩盖了子视图？

如果没有，有没有人遇到过类似的问题？

以下是我的一些custom1代码：

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
    final int count = getChildCount();
    if (ItemToDebug.equals("Layout")){
        if (count == numberOfChannels){
            Log.d("Layout:", "Number of children matches number of channels");
        }else{
            Log.d("Layout:", "Mismatch between number of children and number of channels");
        }
        Log.d("Layout:", "onLayout " + Integer.toString(count) + " children");
    }

    for (int i = 0; i < count; i++){
        View child = getChildAt(i);
        if (i%2 == 0){
            if (LayoutLeftChild(i/2, l, t, r, b, child)){ //Lays out Child, returning a Boolean if successful
                if (ItemToDebug.equals("Layout")){
                    Log.d("Layout:", "onLayoutLeftChild number " + Integer.toString(i/2) + "successful");
                }
            } else
            if (ItemToDebug.equals("Layout")){
                Log.d("Layout:", "onLayoutLeftChild number " + Integer.toString(i/2) + "failed");
            }
        }
        if (i%2 == 1){
            if (LayoutRightChild(i/2, l, t, r, b, child)){
                if (ItemToDebug.equals("Layout")){
                    Log.d("Layout:", "onLayoutRightChild number " + Integer.toString(i/2) + "successful");
                }
            }else{
                if (ItemToDebug.equals("Layout")){
                    Log.d("Layout:", "onLayoutRightChild number " + Integer.toString(i/2) + "failed");
                }
            }
        }
    }

}


/*
Left edge for right column = l + (r-l)/2 + 15
Right edge for right column = r - 20
20dp Margin between rows
Rows are 400 dp tall
 */
private boolean LayoutRightChild(int i, int l, int t, int r, int b, View child) {
    final View Child = child;

    final int Left = l + (r-l)/2 + 15;
    final int Right = r - 20;
    final int Top = t + i*20 + (i-1)*400;
    final int Bottom = Top + 400;

    Child.layout(Left, Top, Right, Bottom);
    if (ItemToDebug.equals("Layout")){
        Log.d("Layout:", "Child laid out at (" + Integer.toString(Left) + ", " + Integer.toString(Top) + ", " + Integer.toString(Right) + ", " + Integer.toString(Bottom) + ")");
    }

    return true;
}



/*
Left edge for left column = l + 20
Right edge for left column = l + (r-l)/2 - 15
20dp Margin between rows
Rows are 400 dp tall
 */
private boolean LayoutLeftChild(int i, int l, int t, int r, int b, View child) {
    final View Child = child;

    final int Left = l + 20;
    final int Right = l + (r-l)/2 - 15;
    final int Top = t + i*20 + (i-1)*400;
    final int Bottom = Top + 400;

    Child.layout(Left, Top, Right, Bottom);

    if (ItemToDebug.equals("Layout")){
        Log.d("Layout:", "Child laid out at (" + Integer.toString(Left) + ", " + Integer.toString(Top) + ", " + Integer.toString(Right) + ", " + Integer.toString(Bottom) + ")");
    }
    return true;
}

以下是来自custom2的一些代码：

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

    final int count = getChildCount(); //There should be three children - one ImageView on top and two TextViews on bottom
    if (ItemToDebug.equals("Layout")){
        if (count == 3){
            Log.d("View Contents:", "3 Children Views found");
        }else{
            Log.d("View Contents:", "Number of Children Incorrect. " + Integer.toString(count) + " children found.");
        }
        Log.d("Layout:", "onLayout " + Integer.toString(count) + " children");
    }

    //Get children here in for loop and place.
    for (int i = 0; i < count; i++){
        final View child = this.getChildAt(i);

        //Layout should already have margins, so align contents with left and right sides.
        int width = r - l;
        int top;
        int height;
        switch(i){
            case 0:
                top = t;
                height = 100;
                if (ItemToDebug.equals("Layout")) {
                    Log.d("Layout:", "Image Laid out at (" + Integer.toString(l) + ", " + Integer.toString(top) + ", " + Integer.toString(r) + ", " + Integer.toString(top + height) + ")");
                }
                break;
            case 1:
                top = t + 100;
                height = 60;
                if (ItemToDebug.equals("Layout")) {
                    Log.d("Layout:", "TextView (nowPlaying) Laid out at (" + Integer.toString(l) + ", " + Integer.toString(top) + ", " + Integer.toString(r) + ", " + Integer.toString(top + height) + ")");
                }
                break;
            case 2:
                top = t + 160;
                height = 60;
                if (ItemToDebug.equals("Layout")) {
                    Log.d("Layout:", "TextView (nextPlaying) Laid Out at (" + Integer.toString(l) + ", " + Integer.toString(top) + ", " + Integer.toString(r) + ", " + Integer.toString(top + height) + ")");
                }
                break;
            default:
                top = t;
                height = 0;
                if (ItemToDebug.equals("Layout")){
                    Log.d("Layout:", "More than 3 children have been added to the Custom2");
                }
                break;
        }

        child.layout(l, top, r, top + height);

    }
}

这是我的日志：

https://drive.google.com/file/d/0B0EGM_1_9jazWEZ1RXh4a2VXdnM/view?usp=sharing

截图。

Screenshot

Answer 1

答案可以在这里找到：Views within a Custom ViewGroup are not showing

孩子们和我们的父母一样（左边和上面都是0）

ViewGroup错误

1 个答案: