圆形ImageView


圆形ImageView

实例

Screenshot_2016-11-21-18-18-51-666_win.haotinayi.fakesms

文中的两处圆形头像

项目地址:GitHub

实现

public class CircleImageView extends ImageView {

    // 控件默认长、宽
    private int defaultWidth = 0;
    private int defaultHeight = 0;

    private int mBorderThickness = 0;

    private Context mContext;

    public CircleImageView(Context context) {
        super(context);
        mContext = context;

    }

    public CircleImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        setCustomAttributes(attrs);
    }

    public CircleImageView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        mContext = context;
        setCustomAttributes(attrs);
    }

    private void setCustomAttributes(AttributeSet attrs) {
        TypedArray a = mContext.obtainStyledAttributes(attrs,
                R.styleable.roundedimageview);
        mBorderThickness = a.getDimensionPixelSize(
                R.styleable.roundedimageview_roundedimageview_border_thickness, 0);

    }

    @Override
    protected void onDraw(Canvas canvas) {

        Drawable drawable = getDrawable();

        if (drawable == null) {
            return;
        }

        if (getWidth() == 0 || getHeight() == 0) {
            return;
        }
        this.measure(0, 0);
        if (drawable.getClass() == NinePatchDrawable.class)
            return;

        Bitmap b = ((BitmapDrawable) drawable).getBitmap();
        Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);
        if (defaultWidth == 0) {
            defaultWidth = getWidth();

        }
        if (defaultHeight == 0) {
            defaultHeight = getHeight();
        }

        int radius = 0;

        radius = (defaultWidth < defaultHeight ? defaultWidth
                : defaultHeight) / 2 - 2 * 5;

        // 画内圆
        drawCircleBorder(canvas, radius + mBorderThickness / 2,
                Color.parseColor("#00BCD4"));
        // 画外圆
        drawCircleBorder(canvas, radius + mBorderThickness
                + mBorderThickness / 2, Color.parseColor("#0097A7"));
        Bitmap roundBitmap = getCroppedRoundBitmap(bitmap, radius);
        canvas.drawBitmap(roundBitmap, defaultWidth / 2 - radius, defaultHeight
                / 2 - radius, null);

    }

    public Bitmap getCroppedRoundBitmap(Bitmap bmp, int radius) {

        Bitmap scaledSrcBmp;
        int diameter = radius * 2;

        // 为了防止宽高不相等,造成圆形图片变形,因此截取长方形中处于中间位置最大的正方形图片
        int bmpWidth = bmp.getWidth();
        int bmpHeight = bmp.getHeight();
        int squareWidth = 0, squareHeight = 0;
        int x = 0, y = 0;
        Bitmap squareBitmap;
        if (bmpHeight > bmpWidth) {// 高大于宽
            squareWidth = squareHeight = bmpWidth;
            x = 0;
            y = (bmpHeight - bmpWidth) / 2;
            // 截取正方形图片
            squareBitmap = Bitmap.createBitmap(bmp, x, y, squareWidth,
                    squareHeight);
        } else if (bmpHeight < bmpWidth) {// 宽大于高
            squareWidth = squareHeight = bmpHeight;
            x = (bmpWidth - bmpHeight) / 2;
            y = 0;
            squareBitmap = Bitmap.createBitmap(bmp, x, y, squareWidth,
                    squareHeight);
        } else {
            squareBitmap = bmp;
        }

        if (squareBitmap.getWidth() != diameter
                || squareBitmap.getHeight() != diameter) {
            scaledSrcBmp = Bitmap.createScaledBitmap(squareBitmap, diameter,
                    diameter, true);

        } else {
            scaledSrcBmp = squareBitmap;
        }
        Bitmap output = Bitmap.createBitmap(scaledSrcBmp.getWidth(),
                scaledSrcBmp.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        Paint paint = new Paint();
        Rect rect = new Rect(0, 0, scaledSrcBmp.getWidth(),
                scaledSrcBmp.getHeight());

        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);
        canvas.drawARGB(0, 0, 0, 0);
        canvas.drawCircle(scaledSrcBmp.getWidth() / 2,
                scaledSrcBmp.getHeight() / 2, scaledSrcBmp.getWidth() / 2,
                paint);
        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(scaledSrcBmp, rect, rect, paint);
        return output;
    }

    /**
     * 边缘画圆
     */
    private void drawCircleBorder(Canvas canvas, int radius, int color) {
        Paint paint = new Paint();
        /* 去锯齿 */
        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);
        paint.setColor(color);
        /* 设置paint的 style 为STROKE:空心 */
        paint.setStyle(Paint.Style.STROKE);
        /* 设置paint的外框宽度 */
        paint.setStrokeWidth(mBorderThickness);
        canvas.drawCircle(defaultWidth / 2, defaultHeight / 2, radius, paint);
    }
}

使用

参见GitHub


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