在Android中,ImageView默认是一个矩形。如何使它成为一个圆角矩形(剪辑我的位图的所有4个角为圆角矩形)在ImageView?
请注意,从2021年起,只需使用ShapeableImageView
在Android中,ImageView默认是一个矩形。如何使它成为一个圆角矩形(剪辑我的位图的所有4个角为圆角矩形)在ImageView?
请注意,从2021年起,只需使用ShapeableImageView
当前回答
芬兰湾的科特林版:
@GlideExtension
object GamersGeekGlideExtension {
@NonNull
@JvmStatic
@GlideOption
fun roundedCorners(options: BaseRequestOptions<*>, context: Context, cornerRadius: Int): BaseRequestOptions<*> {
val px =
(cornerRadius * (context.resources.displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT)).roundToInt()
return options.transforms(RoundedCorners(px))
}
}
注意:Glide扩展现在需要BaseRequestOptions而不是RequestOptions。此外,它与@Sir Codesalot答案在kotlin中转换的函数相同。
其他回答
它可以很容易地完成下面的形状。将其作为src添加到图像中。 如果你想删除边界,只需添加你的背景颜色的边界 :-)
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:drawable="@drawable/img_area_one"
android:bottom="5dp"
android:left="5dp"
android:right="5dp"
android:top="5dp" />
<item>
<shape
android:padding="10dp"
android:shape="rectangle">
<corners
android:topLeftRadius="8dp"
android:topRightRadius="8dp"
/>
<stroke
android:width="5dp"
android:color="@color/white" />
</shape>
</item>
</layer-list>
一个快速的xml解决方案-
<android.support.v7.widget.CardView
android:layout_width="40dp"
android:layout_height="40dp"
app:cardElevation="0dp"
app:cardCornerRadius="4dp">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/rounded_user_image"
android:scaleType="fitXY"/>
</android.support.v7.widget.CardView>
你可以在CardView上设置你想要的宽度,高度和半径,在ImageView上设置scaleType。
对于AndroidX,使用< AndroidX .cardview.widget. cardview >
应用一个形状到你的imageView如下所示:
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<solid android:color="#faf5e6" />
<stroke
android:width="1dp"
android:color="#808080" />
<corners android:radius="15dp" />
<padding
android:bottom="5dp"
android:left="5dp"
android:right="5dp"
android:top="5dp" />
</shape>
这可能对你的朋友有帮助。
我使用路径在图像画布上只画角。(我需要没有位图内存分配的解决方案)
@Override
protected void onDraw(final Canvas canvas) {
super.onDraw(canvas);
if (!hasRoundedCorners()) return;
mPaint.setStyle(Paint.Style.FILL);
mPaint.setStrokeWidth(0);
Path path = new Path();
path.setFillType(Path.FillType.INVERSE_WINDING);
path.addRoundRect(new RectF(0, 0, getWidth(), getHeight()), mRadius, mRadius, Path.Direction.CCW);
canvas.drawPath(path, mPaint);
}
注意,你不应该在onDraw方法中分配任何新对象。此代码是概念验证,不应该在产品代码中这样使用
看到更多: https://medium.com/@przemek.materna/rounded-image-view-no-bitmap-reallocation-11a8b163484d
对于上面提到的乔治·沃尔特斯二世,我只是把他的答案扩展了一下,以支持不同的圆角。这可以进一步优化(一些目标矩形重叠),但不是很多。
我知道这个线程有点老了,但它是谷歌上关于如何在Android上圆角ImageViews的查询的顶级结果之一。
/**
* Use this method to scale a bitmap and give it specific rounded corners.
* @param context Context object used to ascertain display density.
* @param bitmap The original bitmap that will be scaled and have rounded corners applied to it.
* @param upperLeft Corner radius for upper left.
* @param upperRight Corner radius for upper right.
* @param lowerRight Corner radius for lower right.
* @param lowerLeft Corner radius for lower left.
* @param endWidth Width to which to scale original bitmap.
* @param endHeight Height to which to scale original bitmap.
* @return Scaled bitmap with rounded corners.
*/
public static Bitmap getRoundedCornerBitmap(Context context, Bitmap bitmap, float upperLeft,
float upperRight, float lowerRight, float lowerLeft, int endWidth,
int endHeight) {
float densityMultiplier = context.getResources().getDisplayMetrics().density;
// scale incoming bitmap to appropriate px size given arguments and display dpi
bitmap = Bitmap.createScaledBitmap(bitmap,
Math.round(endWidth * densityMultiplier),
Math.round(endHeight * densityMultiplier), true);
// create empty bitmap for drawing
Bitmap output = Bitmap.createBitmap(
Math.round(endWidth * densityMultiplier),
Math.round(endHeight * densityMultiplier), Config.ARGB_8888);
// get canvas for empty bitmap
Canvas canvas = new Canvas(output);
int width = canvas.getWidth();
int height = canvas.getHeight();
// scale the rounded corners appropriately given dpi
upperLeft *= densityMultiplier;
upperRight *= densityMultiplier;
lowerRight *= densityMultiplier;
lowerLeft *= densityMultiplier;
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setColor(Color.WHITE);
// fill the canvas with transparency
canvas.drawARGB(0, 0, 0, 0);
// draw the rounded corners around the image rect. clockwise, starting in upper left.
canvas.drawCircle(upperLeft, upperLeft, upperLeft, paint);
canvas.drawCircle(width - upperRight, upperRight, upperRight, paint);
canvas.drawCircle(width - lowerRight, height - lowerRight, lowerRight, paint);
canvas.drawCircle(lowerLeft, height - lowerLeft, lowerLeft, paint);
// fill in all the gaps between circles. clockwise, starting at top.
RectF rectT = new RectF(upperLeft, 0, width - upperRight, height / 2);
RectF rectR = new RectF(width / 2, upperRight, width, height - lowerRight);
RectF rectB = new RectF(lowerLeft, height / 2, width - lowerRight, height);
RectF rectL = new RectF(0, upperLeft, width / 2, height - lowerLeft);
canvas.drawRect(rectT, paint);
canvas.drawRect(rectR, paint);
canvas.drawRect(rectB, paint);
canvas.drawRect(rectL, paint);
// set up the rect for the image
Rect imageRect = new Rect(0, 0, width, height);
// set up paint object such that it only paints on Color.WHITE
paint.setXfermode(new AvoidXfermode(Color.WHITE, 255, AvoidXfermode.Mode.TARGET));
// draw resized bitmap onto imageRect in canvas, using paint as configured above
canvas.drawBitmap(bitmap, imageRect, imageRect, paint);
return output;
}