无论出于何种原因，设置 minHeight 和 maxHeight 对 ImageView 组件内的图像尺寸没有影响。在某些情况下，我最终会得到一个非常小的图像。我认为这是因为我将宽度和高度设置为“wrap_content”并将“adjustViewBounds”设置为 true。
如果我将“adjustViewBounds”设置为 false，图像会扩展为我为 minWidth 和/或 minHeight 指定的任何内容。但是，在这种情况下，图像会变形，因为它的宽度和高度没有按比例缩放。我也想避免这种情况。
我最终编写了大量代码（如下）来覆盖 ImageView 的 onMeasure() 方法。这真的有必要吗？
public class FlexibleImageView extends ImageView {
private static final String LOG_TAG = "FlexibleImageView";
public FlexibleImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if(Build.VERSION.SDK_INT > Build.VERSION_CODES.JELLY_BEAN) {
boolean adjustViewBounds = getAdjustViewBounds();
int minWidth = Math.max(getMinimumWidth(), getSuggestedMinimumWidth());
int minHeight = Math.max(getMinimumHeight(), getSuggestedMinimumHeight());
int maxWidth = getMaxWidth();
int maxHeight = getMaxHeight();
int widthSpec = getMeasuredWidth();
int heightSpec = getMeasuredHeight();
Drawable d = getDrawable();
if (d != null && adjustViewBounds) {
// Scale UP if the size is too small
float scale, scaleW = 1.0f, scaleH = 1.0f;
if (widthSpec < minWidth)
scaleW = (float) minWidth / (float) widthSpec;
if (heightSpec < minHeight)
scaleH = (float) minHeight / (float) heightSpec;
scale = (scaleW > scaleH) ? scaleW : scaleH;
if (scale > 1.0) {
int targetW = (int) Math.ceil(widthSpec * scale);
int targetH = (int) Math.ceil(heightSpec * scale);
Log.d(LOG_TAG, "Measured dimension (" + widthSpec + "x" + heightSpec
+ ") too small. Resizing to " + targetW + "x" + targetH);
// Make sure targetW, targetH stays within the bounds of maxW, maxH
if(targetW > maxWidth) {
targetH = targetH * maxWidth / targetW;
targetW = maxWidth;
Log.d(LOG_TAG, "Capping width to " + maxWidth);
}
if(targetH > maxHeight) {
targetW = targetW * maxHeight / targetH;
targetH = maxHeight;
Log.d(LOG_TAG, "Capping height to " + maxHeight);
}
setMeasuredDimension(targetW, targetH);
}
}
}
}
}
和 XML 部分：
<cards.myb.ui.FlexibleImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageCard"
android:contentDescription="@string/card_image"
android:adjustViewBounds="true"
android:minHeight="@dimen/card_editor_img_min_dimen"
android:scaleType="fitXY"
android:src="@drawable/fb_logo" />