测量视图和计算比例时不考虑旋转。一个可能的解决方案是自己做:
public class RotatedImageView extends ImageView {
...
constructors
...
private double mRotatedWidth;
private double mRotatedHeight;
private boolean update() {
Drawable d = getDrawable();
if (d == null) {
return false;
}
int drawableWidth = d.getIntrinsicWidth();
int drawableHeight = d.getIntrinsicHeight();
if (drawableWidth <= 0 || drawableHeight <= 0) {
return false;
}
double rotationRad = getRotation() / 180 * Math.PI;
// calculate intrinsic rotated size
// see diagram
mRotatedWidth = (Math.abs(Math.sin(rotationRad)) * drawableHeight
+ Math.abs(Math.cos(rotationRad)) * drawableWidth);
mRotatedHeight = (Math.abs(Math.cos(rotationRad)) * drawableHeight
+ Math.abs(Math.sin(rotationRad)) * drawableWidth);
return true;
}
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
if (update()) {
double ratio = mRotatedWidth / mRotatedHeight;
int wMax = Math.min(getDefaultSize(Integer.MAX_VALUE, widthMeasureSpec), getMaxWidth());
int hMax = Math.min(getDefaultSize(Integer.MAX_VALUE, heightMeasureSpec), getMaxHeight());
int w = (int) Math.min(wMax, hMax * ratio);
int h = (int) Math.min(hMax, wMax / ratio);
setMeasuredDimension(w, h);
} else {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
private final float[] values = new float[9];
protected void onDraw(Canvas canvas) {
if (update()) {
int availableWidth = getMeasuredWidth();
int availableHeight = getMeasuredHeight();
float scale = (float) Math.min(availableWidth / mRotatedWidth, availableHeight / mRotatedHeight);
getImageMatrix().getValues(values);
setScaleX(scale / values[Matrix.MSCALE_X]);
setScaleY(scale / values[Matrix.MSCALE_Y]);
}
super.onDraw(canvas);
}
@Override
public void setRotation(float rotation) {
super.setRotation(rotation);
requestLayout();
}
}
adjustViewBounds
必须是真的:
<com.mypackage.RotatedImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="20dp"
android:adjustViewBounds="true"
android:rotation="90"
android:maxWidth="100dp"
android:maxHeight="100dp"
android:scaleType="fitCenter"
android:src="@drawable/test" />
对计算的很好的解释,礼貌谢蒂坎普 https://stackoverflow.com/questions/43414865/image-out-of-bounds-after-transformation-on-view/43477366?noredirect=1#comment74025272_43477366 :
更新:现在尝试调整边界。之间没有区别wrap_content
and match_parent
(根据图像方面,两者都尽可能增长)。你应该使用maxWidth
和/或maxHeight
,或将其放入LinearLayout
尺寸为 0,重量为 0。
它也不可设置动画,在设置动画时调整边界需要为每个帧进行布局传递,这是非常低效的。请参阅其他答案以了解可用于的版本View.animate()