blocks|key|1141199|text|你可以|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1141200|-(void)viewDidload:+{
++++[yourButton+setTitleColor:(UIColor+*)color+
+++++++++++++++++++++forState:UIControlStateHighlighted];
++++[yourButton+addTarget:self+
+++++++++++++++++++action:@selector(changeButtonBackGroundColor:)+
+++++++++forControlEvents:UIControlEventTouchDown];
}

-(void)changeButtonBackGroundColor:(UIButton+*)button+{
++++[button+setBackgroundColor:[UIColor+yourColor]];
}|code-block|syntax|javascript|1141201|记住用事件来改变它：UIControlEventTouchUpInside和UIControlEventTouchOutSide+:)|offset|length|style|CODE|1141202|entityMap^0|0|0|A|R|12|Q|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|N|$]]

You could set

<pre><code>-(void)viewDidload: {
 [yourButton setTitleColor:(UIColor *)color 
 forState:UIControlStateHighlighted];
 [yourButton addTarget:self 
 action:@selector(changeButtonBackGroundColor:) 
 forControlEvents:UIControlEventTouchDown];
}

-(void)changeButtonBackGroundColor:(UIButton *)button {
 [button setBackgroundColor:[UIColor yourColor]];
}
</code></pre>

remember to change it back with events: <code>UIControlEventTouchUpInside</code> and <code>UIControlEventTouchOutSide</code> :)

blocks|key|1141206|text|您可以使用目标作为混合模式在CGContext上绘制文本。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1141207|这段代码似乎有效：|1141208|-+(void)viewDidLoad
{
++++[super+viewDidLoad];
++++self.view.backgroundColor+=+[UIColor+greenColor];

++++UIFont*+font+=+[UIFont+fontWithName:@"Helvetica-Bold"+size:18];
++++NSString*+buttonText+=+@"BUTTON";
++++CGSize+buttonSize+=++CGSizeMake(200,+50);
++++NSDictionary*+textAttributes+=+@{NSFontAttributeName:font};

++++CGSize+textSize+=+[buttonText+sizeWithAttributes:textAttributes];

++++UIGraphicsBeginImageContextWithOptions(buttonSize,+NO,+[[UIScreen+mainScreen]+scale]);
++++CGContextRef+ctx+=+UIGraphicsGetCurrentContext();

++++CGContextSetFillColorWithColor(ctx,+[UIColor+redColor].CGColor);

++++UIBezierPath+*path+=+[UIBezierPath+bezierPathWithRect:CGRectMake(0,+0,+buttonSize.width,+buttonSize.height)];
++++CGContextAddPath(ctx,+path.CGPath);
++++CGContextFillPath(ctx);

++++CGContextSetBlendMode(ctx,+kCGBlendModeDestinationOut);
++++CGPoint+center+=+CGPointMake(buttonSize.width/2-textSize.width/2,+buttonSize.height/2-textSize.height/2);
++++[@"BUTTON"+drawAtPoint:center+withAttributes:textAttributes];


++++UIImage*+viewImage+=+UIGraphicsGetImageFromCurrentImageContext();

++++UIGraphicsEndImageContext();

++++UIImageView*+imgView+=+[[UIImageView+alloc]+initWithImage:viewImage];
++++[self.view+addSubview:imgView];
}|code-block|syntax|javascript|1141209|顺便说一句，如果您想在一个UIImage中设置UIButton，而不只是将它添加到一个视图中：|1141210|UIButton*+boton+=+[[UIButton+alloc]+initWithFrame:CGRectMake(50,+50,+viewImage.size.width,+viewImage.size.height)];
[boton+setBackgroundColor:[UIColor+clearColor]];
[boton+setTitleColor:[UIColor+redColor]+forState:UIControlStateNormal];
boton.titleLabel.font+=+font;
[boton+setTitle:buttonText+forState:UIControlStateNormal];
[boton+setImage:viewImage+forState:UIControlStateHighlighted];
[self.view+addSubview:boton];|1141211|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

You can draw the text on a CGContext using Destination Out as blend mode.

This code seems to work:

<pre><code>- (void)viewDidLoad
{
 [super viewDidLoad];
 self.view.backgroundColor = [UIColor greenColor];

 UIFont* font = [UIFont fontWithName:@"Helvetica-Bold" size:18];
 NSString* buttonText = @"BUTTON";
 CGSize buttonSize = CGSizeMake(200, 50);
 NSDictionary* textAttributes = @{NSFontAttributeName:font};

 CGSize textSize = [buttonText sizeWithAttributes:textAttributes];

 UIGraphicsBeginImageContextWithOptions(buttonSize, NO, [[UIScreen mainScreen] scale]);
 CGContextRef ctx = UIGraphicsGetCurrentContext();

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

 UIBezierPath *path = [UIBezierPath bezierPathWithRect:CGRectMake(0, 0, buttonSize.width, buttonSize.height)];
 CGContextAddPath(ctx, path.CGPath);
 CGContextFillPath(ctx);

 CGContextSetBlendMode(ctx, kCGBlendModeDestinationOut);
 CGPoint center = CGPointMake(buttonSize.width/2-textSize.width/2, buttonSize.height/2-textSize.height/2);
 [@"BUTTON" drawAtPoint:center withAttributes:textAttributes];


 UIImage* viewImage = UIGraphicsGetImageFromCurrentImageContext();

 UIGraphicsEndImageContext();

 UIImageView* imgView = [[UIImageView alloc] initWithImage:viewImage];
 [self.view addSubview:imgView];
}
</code></pre>

By the way, if you want to set the UIImage in a UIButton instead of just adding it to a view:

<pre><code>UIButton* boton = [[UIButton alloc] initWithFrame:CGRectMake(50, 50, viewImage.size.width, viewImage.size.height)];
[boton setBackgroundColor:[UIColor clearColor]];
[boton setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
boton.titleLabel.font = font;
[boton setTitle:buttonText forState:UIControlStateNormal];
[boton setImage:viewImage forState:UIControlStateHighlighted];
[self.view addSubview:boton];
</code></pre>

I have a custom <code>UIButton</code> with transparent background and white title.
I'm looking for a simple solution to invert it on highlight (white background and transparent title) as it is achieved on system <code>UISegmentedControl</code>. 

Is there simpler solution than inverting alpha on snapshot used as a <code>CALayer</code> mask?

If not, could you tell how can I invert <code>CALayer</code> alpha?

iOS UIButton with transparent title on white background

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

我有一个具有透明背景和白色标题的定制UIButton。我正在寻找一个简单的解决方案，以颠倒它的高亮(白色背景和透明标题)，因为它是在系统UISegmentedControl上实现的。在用作CALayer掩码的快照上，有比反转alpha更简单的解决方案吗？如果没有，你能告诉我如何反演CALayerα吗？

问白色背景上透明标题的iOS UIButton
EN

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问白色背景上透明标题的iOS UIButtonEN