[英]How to make UITabbar transparent so that background image of superview is visible?
[英]How to make selected area of a superview transparent
有什么辦法可以使僅選定的視圖透明區域透明? 我有一個具有黑色(alpha 0.5)背景色的UIView。 我在UIView上放置了一些空心的圓,並希望UIView的下面是透明的,以便可以看穿它。 任何想法
- (id)initWithFrame:(CGRect)iFrame andHollowFrames:(NSArray *)iHollowFrames withRadius:(NSNumber *)iRadius {
if ((self = [super initWithFrame:iFrame]) != nil) {
self.hollowFrames = [[NSSet setWithArray:iHollowFrames] allObjects];
self.hollowCircleRadius = iRadius;
[self addShadowView];
}
return self;
}
- (void)addShadowView {
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height) cornerRadius:0];
for (NSValue *point in self.hollowFrames) {
UIBezierPath *circlePath = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(point.CGPointValue.x - self.hollowCircleRadius.floatValue, point.CGPointValue.y - self.hollowCircleRadius.floatValue, 2.0 * self.hollowCircleRadius.floatValue, 2.0 * self.hollowCircleRadius.floatValue) cornerRadius:self.hollowCircleRadius.floatValue];
[path appendPath:circlePath];
}
[path setUsesEvenOddFillRule:YES];
CAShapeLayer *fillLayer = [CAShapeLayer layer];
fillLayer.path = path.CGPath;
fillLayer.fillRule = kCAFillRuleEvenOdd;
fillLayer.fillColor = [UIColor blackColor].CGColor;
fillLayer.opacity = 0.5;
[self.layer addSublayer:fillLayer];
}
這是一個UIView子類解決方案。 為了使它起作用,您必須保留superviews backgroundColor屬性,因為nil witch是默認值。 如果此UIView子類在情節提要中,請確保在屬性檢查器中將背景色設置為“透明色”。
- (void)drawRect:(CGRect)rect
{
CGContextRef ctx = UIGraphicsGetCurrentContext();
UIColor *blackBackgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0.5];
CGContextSetFillColorWithColor(ctx, blackBackgroundColor.CGColor);
CGContextFillRect(ctx, rect);
CGRect transparentPart = CGRectMake(10, 10, 120, 80);
CGContextClearRect(ctx, transparentPart);
}
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.