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
多亏了melanke,你可以使用一个自定义类并创建一个自定义循环ImageView。
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
public class MLRoundedImageView extends android.support.v7.widget.AppCompatImageView {
public MLRoundedImageView(Context context) {
super(context);
}
public MLRoundedImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public MLRoundedImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
protected void onDraw(Canvas canvas) {
Drawable drawable = getDrawable();
if (drawable == null) {
return;
}
if (getWidth() == 0 || getHeight() == 0) {
return;
}
Bitmap b = ((BitmapDrawable) drawable).getBitmap();
Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);
int w = getWidth(), h = getHeight();
Bitmap roundBitmap = getCroppedBitmap(bitmap, w);
canvas.drawBitmap(roundBitmap, 0, 0, null);
}
public static Bitmap getCroppedBitmap(Bitmap bmp, int radius) {
Bitmap sbmp;
if (bmp.getWidth() != radius || bmp.getHeight() != radius) {
float smallest = Math.min(bmp.getWidth(), bmp.getHeight());
float factor = smallest / radius;
sbmp = Bitmap.createScaledBitmap(bmp, (int)(bmp.getWidth() / factor), (int)(bmp.getHeight() / factor), false);
} else {
sbmp = bmp;
}
Bitmap output = Bitmap.createBitmap(radius, radius,
Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final int color = 0xffa19774;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, radius, radius);
paint.setAntiAlias(true);
paint.setFilterBitmap(true);
paint.setDither(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(Color.parseColor("#BAB399"));
canvas.drawCircle(radius / 2 + 0.7f,
radius / 2 + 0.7f, radius / 2 + 0.1f, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(sbmp, rect, rect, paint);
return output;
}
}
然后在XML中使用它:
<your.package.name.MLRoundedImageView
..
/>
源
其他回答
非常感谢第一个回答。下面是修改后的版本,将矩形图像转换为正方形(和圆形),填充颜色作为参数传递。
public static Bitmap getRoundedBitmap(Bitmap bitmap, int pixels, int color) {
Bitmap inpBitmap = bitmap;
int width = 0;
int height = 0;
width = inpBitmap.getWidth();
height = inpBitmap.getHeight();
if (width <= height) {
height = width;
} else {
width = height;
}
Bitmap output = Bitmap.createBitmap(width, height, Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, width, height);
final RectF rectF = new RectF(rect);
final float roundPx = pixels;
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(inpBitmap, rect, rect, paint);
return output;
}
在支持库的v21中,现在有了一个解决方案:它被称为RoundedBitmapDrawable。
它基本上就像一个普通的Drawable,除了你给它一个角半径的剪辑:
setCornerRadius(float cornerRadius)
所以,从Bitmap src和一个目标ImageView开始,它看起来像这样:
RoundedBitmapDrawable dr = RoundedBitmapDrawableFactory.create(res, src);
dr.setCornerRadius(cornerRadius);
imageView.setImageDrawable(dr);
使用这个得到圆形图像与边界
public static Bitmap getCircularBitmapWithBorder(Bitmap bitmap, int bordercolor) {
if (bitmap == null || bitmap.isRecycled()) {
return null;
}
int borderWidth=(int)(bitmap.getWidth()/40);
final int width = bitmap.getWidth() + borderWidth;
final int height = bitmap.getHeight() + borderWidth;
Bitmap canvasBitmap = Bitmap.createBitmap(width, height,
Bitmap.Config.ARGB_8888);
BitmapShader shader = new BitmapShader(bitmap, TileMode.CLAMP,
TileMode.CLAMP);
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setShader(shader);
Canvas canvas = new Canvas(canvasBitmap);
float radius = width > height ? ((float) height) / 2f
: ((float) width) / 2f;
canvas.drawCircle(width / 2, height / 2, radius, paint);
paint.setShader(null);
paint.setStyle(Paint.Style.STROKE);
paint.setColor(bordercolor);
paint.setStrokeWidth(borderWidth);
canvas.drawCircle(width / 2, height / 2, radius - borderWidth / 2,
paint);
return canvasBitmap;
}
对于圆形边界使用下面的代码
<com.google.android.material.card.MaterialCardView
android:id="@+id/circle"
android:layout_width="45dp"
android:layout_height="45dp"
android:layout_marginStart="5dp"
app:cardCornerRadius="25dp"
app:strokeColor="@color/colorDarkGreen"
app:strokeWidth="1dp">
<ImageView
android:id="@+id/toolbarProfile"
android:scaleType="fitXY"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="@drawable/avater" />
</com.google.android.material.card.MaterialCardView>
这里使用ImageLoader
创建DisplayImageOptions:
DisplayImageOptions options = new DisplayImageOptions.Builder()
// this will make circle, pass the width of image
.displayer(new RoundedBitmapDisplayer(getResources().getDimensionPixelSize(R.dimen.image_dimen_menu)))
.cacheOnDisc(true)
.build();
imageLoader.displayImage(url_for_image,ImageView,options);
或者你也可以从Square上使用毕加索图书馆。
Picasso.with(mContext)
.load(com.app.utility.Constants.BASE_URL+b.image)
.placeholder(R.drawable.profile)
.error(R.drawable.profile)
.transform(new RoundedTransformation(50, 4))
.resizeDimen(R.dimen.list_detail_image_size, R.dimen.list_detail_image_size)
.centerCrop()
.into(v.im_user);
你可以在这里下载RoundedTransformation文件 在这里