如何防止ImageView调整其父级的大小？

Question

  

注意：我已检查了this question，但没有一个答案有帮助。我正在重述这个问题以说明我的具体问题和需求。

我在我的Android应用中制作了一个自定义视图，显示即将发生的事件（标题，位置，价格，描述等）的数据。除此数据外，此视图还显示图标和封面照片（图标显示在视图左上角的ImageView中，并且封面被修改为具有{{alpha} 1}}，然后在后面显示视图的内容。到目前为止，这是我的布局：

128

当<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/eventview_main" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginLeft="@dimen/activity_horizontal_margin" android:layout_marginRight="@dimen/activity_horizontal_margin" android:layout_marginTop="@dimen/activity_vertical_margin" android:background="@color/color_black" android:elevation="16dp"> <!-- OBJECT IN QUESTION --> <ImageView android:id="@+id/eventview_cover" android:layout_width="match_parent" android:layout_height="match_parent" android:adjustViewBounds="false" android:cropToPadding="false" android:scaleType="centerCrop" /> <ImageView android:id="@+id/eventview_icon" android:layout_width="100dp" android:layout_height="100dp" android:layout_marginLeft="@dimen/half_margin" android:layout_marginRight="@dimen/half_margin" android:layout_marginTop="@dimen/half_margin" android:elevation="8dp" /> <TextView android:id="@+id/eventview_title" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/eventview_price" android:layout_alignParentEnd="true" android:layout_alignParentRight="true" android:layout_alignParentTop="true" android:layout_marginTop="@dimen/half_margin" android:layout_toEndOf="@+id/eventview_icon" android:layout_toRightOf="@+id/eventview_icon" android:text="Large Text" android:textAppearance="?android:attr/textAppearanceLarge" android:textColor="@color/color_white" /> <TextView android:id="@+id/eventview_location" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentEnd="true" android:layout_alignParentRight="true" android:layout_below="@+id/eventview_price" android:layout_toEndOf="@+id/eventview_icon" android:layout_toRightOf="@+id/eventview_icon" android:text="Small Text" android:textAppearance="?android:attr/textAppearanceSmall" android:textColor="@color/color_white" /> <TextView android:id="@+id/eventview_price" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentEnd="true" android:layout_alignParentRight="true" android:layout_below="@+id/eventview_title" android:layout_toEndOf="@+id/eventview_icon" android:layout_toRightOf="@+id/eventview_icon" android:text="Small Text" android:textAppearance="?android:attr/textAppearanceSmall" android:textColor="@color/color_white" /> <TextView android:id="@+id/eventview_shortdesc" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/eventview_title" android:layout_alignParentEnd="true" android:layout_alignParentLeft="true" android:layout_alignParentRight="true" android:layout_alignParentStart="true" android:layout_alignStart="@+id/eventview_title" android:layout_below="@+id/eventview_icon" android:layout_marginBottom="@dimen/half_margin" android:layout_marginLeft="@dimen/half_margin" android:text="Medium Text" android:textAppearance="?android:attr/textAppearanceMedium" android:textColor="@color/color_white" android:width="0dip" /> </RelativeLayout> 实例化我的视图时，它必须提供数据源（自定义类）。然后（在Activity下）调用方法setSource()，该方法设置图标图像和各种updateLayout()。此外，它会将TextView的来源设置为eventview_cover（以修改原始照片的字母）。反过来，这会扩展视图的高度（我想避免）。视图的高度应仅由BitmapDrawable的高度和图标的TextView决定。这是ImageView的代码：

EventView

这一切都有效，但它会调整视图大小以便为封面照片腾出空间，这也是我想要避免的。我在设置drawable之前尝试使用public class EventView extends RelativeLayout { private MergeEvent src = null; public MergeEvent getSource() { return src; } protected void setSource(MergeEvent e) { src = e; //The data was updated, so we need to update the view! updateLayout(); } public EventView(MergeEvent src, Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); setSource(src); } public EventView(MergeEvent src, Context context, AttributeSet attrs) { super(context, attrs); setSource(src); } public EventView(MergeEvent src, Context context) { super(context); setSource(src); } protected void updateLayout() { if (getSource() != null) { //Get source data. MergeEvent src = getSource(); //Set the layout. View.inflate(getContext(), R.layout.eventview, this); //Get references to the TextViews and ImageViews TextView title = (TextView)findViewById(R.id.eventview_title), price = (TextView)findViewById(R.id.eventview_price), location = (TextView)findViewById(R.id.eventview_location), shortdesc = (TextView)findViewById(R.id.eventview_shortdesc); ImageView icon = (ImageView)findViewById(R.id.eventview_icon), cover = (ImageView)findViewById(R.id.eventview_cover); icon.setImageBitmap(src.getIcon()); title.setText(src.getTitle()); price.setText("$" + src.getPrice()); location.setText(src.getLocation()); shortdesc.setText(src.getShortDescription()); //Create a new BitmapDrawable from the source's cover (a Bitmap) BitmapDrawable bd = new BitmapDrawable(getResources(), src.getCover()); bd.setAlpha(128); bkg.setImageDrawable(bd); requestLayout(); } } } ，然后设置drawable，并使用getHeight()设置封面ImageView的高度，但调用{ {1}}已返回bkg.getLayoutParams().height = height，因为此时视图在技术上不可见，因此封面照片不可见。视图应该如下所示，背景图像被裁剪并居中：

TL;博士/总结

如何阻止getHeight()调整其父级的大小？

Answer 1

我在另一个与我非常相似的问题上找到了this answer：

  

这需要使用代码完成。您需要在屏幕渲染后几毫秒调用这些大小的API。因此，如果您在100毫秒后调用它，使用已呈现的任何视图的postDelayed方法，您将获得大小。

使用它，我将updateLayout()方法修改为：

protected void updateLayout() {
    if (getSource() != null) {
        MergeEvent src = getSource();
        View.inflate(getContext(), R.layout.eventview, this);
        TextView title = (TextView)findViewById(R.id.eventview_title);
        TextView price = (TextView)findViewById(R.id.eventview_price);
        TextView location = (TextView)findViewById(R.id.eventview_location);
        TextView shortdesc = (TextView)findViewById(R.id.eventview_shortdesc);
        ImageView i = (ImageView)findViewById(R.id.eventview_icon);
        i.setImageBitmap(src.getIcon());
        title.setText(src.getTitle());
        price.setText("$" + src.getPrice());
        location.setText(src.getLocation());
        shortdesc.setText(src.getShortDescription());
        //use postDelay to set the ImageView's source and max size after 100 miliseconds (plenty of time for the UI to be drawn)
        this.postDelayed(new Runnable() {

            @Override
            public void run() {
                BitmapDrawable bd = new BitmapDrawable(getResources(), src.getCover());
                bd.setAlpha(128);
                ImageView bkg = (ImageView)findViewById(R.id.eventview_cover);
                bkg.setMaxHeight(getHeight());
                bkg.setImageDrawable(bd);
            }

        }, 100);
        requestLayout();
    }
}