ios CGContextRef fill color - ios

Question

I want to draw an arc and fill it. The first picture is what it is. I want to get the effect of the second picture
- (id)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
// 必须清空背景色，不然绘制出来的区域之外有黑色背景
[self setBackgroundColor:[UIColor clearColor]];
[self setUserInteractionEnabled:NO];
}
return self;
}
- (void)drawRect:(CGRect)rect {
float x = rect.origin.x;
float y = rect.origin.y;
float w = rect.size.width;
float h = rect.size.height;
CGContextRef context = UIGraphicsGetCurrentContext();
UIColor *fullColor = [UIColor whiteColor];
CGContextSetFillColorWithColor(context, fullColor.CGColor);
CGContextSetRGBStrokeColor(context,1,1,1,1);
CGContextMoveToPoint(context,0,h - 22);//圆弧的起始点
CGContextAddQuadCurveToPoint(context, w / 2, h, w, h - 22);
CGContextMoveToPoint(context,0,h - 22);//圆弧的起始点
CGContextAddLineToPoint(context, 0, h);
CGContextAddLineToPoint(context, w, h);
CGContextAddLineToPoint(context, w, h - 22);
CGContextStrokePath(context);
CGContextDrawPath(context, kCGPathFillStroke);
}

Answer 1

- (void)drawRect:(CGRect)rect {
float x = rect.origin.x;
float y = rect.origin.y;
float w = rect.size.width;
float h = rect.size.height;
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextFillRect(context, CGRectMake(0, h - 22, kScreenWidth , 22));
CGContextSetFillColorWithColor(context, [UIColor clearColor].CGColor);
// This method
CGContextSetBlendMode(context, kCGBlendModeClear);
CGContextMoveToPoint(context,0,h - 22);
CGContextAddQuadCurveToPoint(context, w / 2, h + 14, w, h - 22);
CGContextDrawPath(context, kCGPathFill);
// This method
CGContextSetBlendMode(context, kCGBlendModeNormal);
}
I found a solution.

Answer 2

CGContextStrokePath() clears the current path. This also applies to CGContextDrawPath(), CGContextEOFillPath(), and, CGContextFillPath().
So when the call CGContextDrawPath(context, kCGPathFillStroke); is made, the current path in the context has just been cleared and is an empty path and nothing is drawn.
Removing the line CGContextStrokePath(context); just above should fix your issue.