如何绘制高斯模糊效果？

Question

我需要使用Objective C在UIView上绘制模糊效果。

这是我的设计

    UIBlurEffect *blurEffect = [UIBlurEffect effectWithStyle: UIBlurEffectStyleExtraLight];

    UIVisualEffectView *contentView = [[UIVisualEffectView alloc] initWithEffect: blurEffect];

    contentView.layer.cornerRadius = 18.0;

    contentView.layer.masksToBounds = YES;

    contentView.backgroundColor = [UIColor whiteColor];

    contentView.userInteractionEnabled = NO;

    contentView.layer.shadowRadius = 10;

    contentView.layer.shadowOpacity = 0.2f;

    contentView.layer.shadowColor = [UIColor whiteColor].CGColor;

    contentView.layer.shadowOffset =  CGSizeZero;

    [contentView setFrame: annotationFrame];

    [contentView setTranslatesAutoresizingMaskIntoConstraints: YES];

    self.contentView = contentView;

下面的屏幕截图是使用上述代码的当前输出

我已经尝试了上面的代码。 ，但是我没有得到确切的模糊效果 请建议我绘制此设计。

我更新了以下代码

- (void)drawRect:(CGRect)rect {

    [super drawRect: rect]; //i doubt we need a super drarRect here…

    [self drawMarker: self.markerView fillColor: [UIColor whiteColor]];

    CGContextRef ctx = UIGraphicsGetCurrentContext();


    CGPathRef path = CGPathCreateWithRoundedRect(CGRectInset(rect,  self.frame.size.width/4,  self.frame.size.height/4), self.frame.size.width/8, self.frame.size.height/8, nil);

    CGContextSetFillColorWithColor(ctx,[UIColor slateColor].CGColor);

    CGContextSetShadowWithColor(ctx, CGSizeZero, self.frame.size.height/4,  [UIColor slateColor].CGColor);


    for ( int i = 0; i<=6; i++) {
        CGContextAddPath(ctx, path);
        CGContextFillPath(ctx);
    }

}

我需要视图后的模糊效果，请为此向我提出建议。

谢谢。

Answer 1

将我先前的答案从迅速转变为Objective-C，我们有了

private class MakeRequestTask extends AsyncTask<Void, Void, List<String>> {
    private Exception mLastError = null;

    MakeRequestTask() {
        //Some stuff
    }

    @Override
    protected List<String> doInBackground(Void... params) {
        //Some stuff
    }

    @Override
    protected void onPreExecute() {
        //Some stuff
    }

    @Override
    protected void onPostExecute(List<String> output) {
// swipe layout will not be shown if fragment is not visible or destroyed
        if(isFragmentVisible){
              swipeRefreshLayout.setRefreshing(false);
            }
// toast will be shown no matter what fragment is visible
         Toast.makeText(getActivity(), "TO_DISPLAY", Toast.LENGTH_SHORT).show();            
        }

    @Override
    protected void onCancelled() {
       if(isFragmentVisible){
              swipeRefreshLayout.setRefreshing(false);
            }
        //Some stuff
    }
}

结果

Answer 2

查看以下我用于模糊效果的参考：

https://dzone.com/articles/applying-gaussian-blur-to-uiviews-with-swift-proto

这仅适用于高斯模糊效果。