我想指定这两个分钟。宽度/高度和最大值ImageView的宽度/高度。图像应缩放以适合。
这样做：
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:minWidth="100dp"
android:maxWidth="200dp"
android:minHeight="100dp"
android:maxHeight="200dp"
android:src="@drawable/ic_launcher" />
最小的宽度和高度按照应有的方式执行，但最大值宽度和高度被忽略。
如果我设置android：adjustViewBounds =“true”：
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:scaleType="fitCenter"
android:minWidth="100dp"
android:maxWidth="200dp"
android:minHeight="100dp"
android:maxHeight="200dp"
android:src="@drawable/ic_launcher" />
比，最大宽度和高度应尽可能，但最小。宽度和高度被忽略。
有没有办法让两者都有？
最后，我创建了自己的视图，它可以访问ImageView并覆盖onMeasure（）：
public class ResizingImageView extends ImageView {
private int mMaxWidth;
private int mMaxHeight;
public ResizingImageView(Context context) {
super(context);
}
public ResizingImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ResizingImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public void setMaxWidth(int maxWidth) {
super.setMaxWidth(maxWidth);
mMaxWidth = maxWidth;
}
@Override
public void setMaxHeight(int maxHeight) {
super.setMaxHeight(maxHeight);
mMaxHeight = maxHeight;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
Drawable drawable = getDrawable();
if (drawable != null) {
int wMode = MeasureSpec.getMode(widthMeasureSpec);
int hMode = MeasureSpec.getMode(heightMeasureSpec);
if (wMode == MeasureSpec.EXACTLY || hMode == MeasureSpec.EXACTLY) {
return;
}
// Calculate the most appropriate size for the view. Take into
// account minWidth, minHeight, maxWith, maxHeigh and allowed size
// for the view.
int maxWidth = wMode == MeasureSpec.AT_MOST
? Math.min(MeasureSpec.getSize(widthMeasureSpec), mMaxWidth)
: mMaxWidth;
int maxHeight = hMode == MeasureSpec.AT_MOST
? Math.min(MeasureSpec.getSize(heightMeasureSpec), mMaxHeight)
: mMaxHeight;
int dWidth = Helpers.dipsToPixels(drawable.getIntrinsicWidth());
int dHeight = Helpers.dipsToPixels(drawable.getIntrinsicHeight());
float ratio = ((float) dWidth) / dHeight;
int width = Math.min(Math.max(dWidth, getSuggestedMinimumWidth()), maxWidth);
int height = (int) (width / ratio);
height = Math.min(Math.max(height, getSuggestedMinimumHeight()), maxHeight);
width = (int) (height * ratio);
if (width > maxWidth) {
width = maxWidth;
height = (int) (width / ratio);
}
setMeasuredDimension(width, height);
}
}
}
现在可以使用此视图，如：
<my.package.ResizingImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:minWidth="100dp"
android:maxWidth="200dp"
android:minHeight="100dp"
android:maxHeight="200dp"
android:src="@drawable/ic_launcher" />
这可以按照我的意愿工作，但不应该有更简单的解决方案吗？
最后，我创建了自己的视图，它可以访问ImageView并覆盖onMeasure（）：
public class ResizingImageView extends ImageView {
private int mMaxWidth;
private int mMaxHeight;
public ResizingImageView(Context context) {
super(context);
}
public ResizingImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ResizingImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public void setMaxWidth(int maxWidth) {
super.setMaxWidth(maxWidth);
mMaxWidth = maxWidth;
}
@Override
public void setMaxHeight(int maxHeight) {
super.setMaxHeight(maxHeight);
mMaxHeight = maxHeight;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
Drawable drawable = getDrawable();
if (drawable != null) {
int wMode = MeasureSpec.getMode(widthMeasureSpec);
int hMode = MeasureSpec.getMode(heightMeasureSpec);
if (wMode == MeasureSpec.EXACTLY || hMode == MeasureSpec.EXACTLY) {
return;
}
// Calculate the most appropriate size for the view. Take into
// account minWidth, minHeight, maxWith, maxHeigh and allowed size
// for the view.
int maxWidth = wMode == MeasureSpec.AT_MOST
? Math.min(MeasureSpec.getSize(widthMeasureSpec), mMaxWidth)
: mMaxWidth;
int maxHeight = hMode == MeasureSpec.AT_MOST
? Math.min(MeasureSpec.getSize(heightMeasureSpec), mMaxHeight)
: mMaxHeight;
int dWidth = Helpers.dipsToPixels(drawable.getIntrinsicWidth());
int dHeight = Helpers.dipsToPixels(drawable.getIntrinsicHeight());
float ratio = ((float) dWidth) / dHeight;
int width = Math.min(Math.max(dWidth, getSuggestedMinimumWidth()), maxWidth);
int height = (int) (width / ratio);
height = Math.min(Math.max(height, getSuggestedMinimumHeight()), maxHeight);
width = (int) (height * ratio);
if (width > maxWidth) {
width = maxWidth;
height = (int) (width / ratio);
}
setMeasuredDimension(width, height);
}
}
}
现在可以使用此视图，如：
<my.package.ResizingImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:minWidth="100dp"
android:maxWidth="200dp"
android:minHeight="100dp"
android:maxHeight="200dp"
android:src="@drawable/ic_launcher" />
这可以按照我的意愿工作，但不应该有更简单的解决方案吗？
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minWidth="150dp"
android:minHeight="150dp"
>
<RelativeLayout
android:id="@+id/imageLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/white"
android:layout_gravity="center_vertical"
>
<ImageView
android:id="@+id/image"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:src="@drawable/trump"
/>
<ProgressBar
android:id="@+id/progressBar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:visibility="gone" />
</RelativeLayout>
</LinearLayout>
请参阅给出容器布局的最小高度和宽度，并将adjustViewBounds放在Imageview中。这样，您的任务将以简单的步骤完成。