Android 图片圆角实现方法

效果：圆角，圆形，椭圆形

 

实现方法：

工具方法

/**
 * 设置BitmapShader
 */
private void setBitmapShader() {
    Drawable drawable = getDrawable();
    if (null == drawable) {
        return;
    }
    Bitmap bitmap = drawableToBitmap(drawable);
    // 将bitmap作为着色器来创建一个BitmapShader
    mBitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
    float scale = 1.0f;
    if (mType == TYPE_CIRCLE) {
        // 拿到bitmap宽或高的小值
        int bSize = Math.min(bitmap.getWidth(), bitmap.getHeight());
        scale = mWidth * 1.0f / bSize;

    } else if (mType == TYPE_ROUND || mType == TYPE_OVAL) {
        // 如果图片的宽或者高与view的宽高不匹配，计算出需要缩放的比例；缩放后的图片的宽高，一定要大于我们view的宽高；所以我们这里取大值；
        scale = Math.max(getWidth() * 1.0f / bitmap.getWidth(), getHeight() * 1.0f / bitmap.getHeight());
    }
    // shader的变换矩阵，我们这里主要用于放大或者缩小
    mMatrix.setScale(scale, scale);
    // 设置变换矩阵
    mBitmapShader.setLocalMatrix(mMatrix);
    mPaint.setShader(mBitmapShader);

}

/**
 * drawable转bitmap
 *
 * @param drawable
 * @return
 */
private Bitmap drawableToBitmap(Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
        BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
        return bitmapDrawable.getBitmap();
    }
    int w = drawable.getIntrinsicWidth();
    int h = drawable.getIntrinsicHeight();
    Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, w, h);
    drawable.draw(canvas);
    return bitmap;
}

绘制方法

@Override
protected void onDraw(Canvas canvas) {

    if (null == getDrawable()) {
        return;
    }
    setBitmapShader();
    if (mType == TYPE_CIRCLE) {
        canvas.drawCircle(mRadius, mRadius, mRadius, mPaint);
    } else if (mType == TYPE_ROUND) {
        mPaint.setColor(Color.RED);
        canvas.drawRoundRect(mRect, mRoundRadius, mRoundRadius, mPaint);
    }else if(mType == TYPE_OVAL){
        canvas.drawOval(mRect, mPaint);
    }
}

 

demo地址：https://download.csdn.net/download/meixi_android/11896635

 

demo云盘：https://pan.baidu.com/s/1c6Crvgd0rHWChtjfkjWJag&shfl=sharepset

在线bug交流：QQ1085220040