android - 圆形图像周围的Android圆形边框

Question

我这样做是为了得到一个圆形ImageView，我怎样才能像这张图片一样在它周围添加一个圆形边框：

public static Bitmap getRoundedShape(Bitmap scaleBitmapImage,int width) {
    int targetWidth = width;
    int targetHeight = width;
    Bitmap targetBitmap = Bitmap.createBitmap(targetWidth, 
            targetHeight,Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(targetBitmap);
    Path path = new Path();
    path.addCircle(((float) targetWidth - 1) / 2,
            ((float) targetHeight - 1) / 2,
            (Math.min(((float) targetWidth), 
            ((float) targetHeight)) / 2),
            Path.Direction.CCW);
    canvas.clipPath(path);
    Bitmap sourceBitmap = scaleBitmapImage;
    canvas.drawBitmap(sourceBitmap, 
            new Rect(0, 0, sourceBitmap.getWidth(),
            sourceBitmap.getHeight()), 
            new Rect(0, 0, targetWidth, targetHeight), null);
    return targetBitmap;
}

Answer 1

关于此功能有一篇非常有趣的帖子： http ://www.curious-creature.org/2012/12/11/android-recipe-1-image-with-rounded-corners/ 它是由 Romain Guy 编写的（例如谷歌的安卓团队）。

你可以使用这样的东西：这个例子创建一个圆形位图，周围有一个白色的笔触。您可以更改它，添加带有黑线的白色笔触。

public class CircleDrawable extends Drawable {

    private final BitmapShader mBitmapShader;
    private final Paint mPaint;
    private Paint mWhitePaint;
    int circleCenterX;
    int circleCenterY;
    int mRadus;
    private boolean mUseStroke = false;
    private int mStrokePadding = 0;

    public CircleDrawable(Bitmap bitmap) {

        mBitmapShader = new BitmapShader(bitmap,
                Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);

        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setShader(mBitmapShader);

    }

    public CircleDrawable(Bitmap bitmap, boolean mUseStroke) {
        this(bitmap);

        if (mUseStroke) {
            this.mUseStroke = true;
            mStrokePadding = 4;
            mWhitePaint = new Paint();
            mWhitePaint.setStyle(Paint.Style.FILL_AND_STROKE);
            mWhitePaint.setStrokeWidth(0.75f);
            mWhitePaint.setColor(Color.WHITE);
        }
    }

    @Override
    protected void onBoundsChange(Rect bounds) {
        super.onBoundsChange(bounds);
        circleCenterX = bounds.width() / 2;
        circleCenterY = bounds.height() / 2;

        if (bounds.width() >= bounds.height())
            mRadus = bounds.width() / 2;
        else
            mRadus = bounds.height() / 2;
    }

    @Override
    public void draw(Canvas canvas) {
        if (mUseStroke) {
            canvas.drawCircle(circleCenterX, circleCenterY, mRadus, mWhitePaint);
        }
        canvas.drawCircle(circleCenterX, circleCenterY, mRadus - mStrokePadding, mPaint);
    }

    @Override
    public int getOpacity() {
        return PixelFormat.TRANSLUCENT;
    }

    @Override
    public void setAlpha(int alpha) {
        mPaint.setAlpha(alpha);
    }

    @Override
    public void setColorFilter(ColorFilter cf) {
        mPaint.setColorFilter(cf);
    }

    public boolean ismUseStroke() {
        return mUseStroke;
    }

    public void setmUseStroke(boolean mUseStroke) {
        this.mUseStroke = mUseStroke;
    }

}