UIButton의 배경 이미지로 사용할 UIColor에서 UIImage 만들기

UIButton의 배경 이미지로 사용할 UIColor에서 UIImage 만들기

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이 질문에는 이미 답변이 있습니다.

• iPhone에서 컬러 1x1 UIImage를 동적으로 만드는 방법은 무엇입니까? 답변 6 개

다음과 같이 컬러 이미지를 만들고 있습니다.

CGRect rect = CGRectMake(0, 0, 1, 1);
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context,
                                   [[UIColor redColor] CGColor]);
//  [[UIColor colorWithRed:222./255 green:227./255 blue: 229./255 alpha:1] CGColor]) ;
CGContextFillRect(context, rect);
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

그런 다음 버튼의 배경 이미지로 사용하십시오.

[resultButton setBackgroundImage:img forState:UIControlStateNormal];

이것은 redColor를 사용하면 효과적이지만 RGB 라인을 사용하고 싶습니다 (주석에 표시된 것처럼). RGB 색상을 사용하면 버튼 배경이 변경되지 않습니다.내가 무엇을 놓치고 있습니까?

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버튼의 배경색을 설정하고 상태를 설정할 수 있도록 UIButton 주위에 범주를 만들었습니다. 이 기능이 유용 할 수 있습니다.

@implementation  UIButton (ButtonMagic)

- (void)setBackgroundColor:(UIColor *)backgroundColor forState:(UIControlState)state {
    [self setBackgroundImage:[UIButton imageFromColor:backgroundColor] forState:state];
}

+ (UIImage *)imageFromColor:(UIColor *)color {
    CGRect rect = CGRectMake(0, 0, 1, 1);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

이것은 이번 달에 내가 오픈 소싱 도우미 카테고리 세트의 일부가 될 것입니다.스위프트 2.2

extension UIImage {
static func fromColor(color: UIColor) -> UIImage {
    let rect = CGRect(x: 0, y: 0, width: 1, height: 1)
    UIGraphicsBeginImageContext(rect.size)
    let context = UIGraphicsGetCurrentContext()
    CGContextSetFillColorWithColor(context, color.CGColor)
    CGContextFillRect(context, rect)
    let img = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return img
  }
}

스위프트 3.0

extension UIImage {
    static func from(color: UIColor) -> UIImage {
        let rect = CGRect(x: 0, y: 0, width: 1, height: 1)
        UIGraphicsBeginImageContext(rect.size)
        let context = UIGraphicsGetCurrentContext()
        context!.setFillColor(color.cgColor)
        context!.fill(rect)
        let img = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return img!
    }
}

로 사용

let img = UIImage.from(color: .black)

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Xamarin.iOS 솔루션

 public UIImage CreateImageFromColor()
 {
     var imageSize = new CGSize(30, 30);
     var imageSizeRectF = new CGRect(0, 0, 30, 30);
     UIGraphics.BeginImageContextWithOptions(imageSize, false, 0);
     var context = UIGraphics.GetCurrentContext();
     var red = new CGColor(255, 0, 0);
     context.SetFillColor(red);
     context.FillRect(imageSizeRectF);
     var image = UIGraphics.GetImageFromCurrentImageContext();
     UIGraphics.EndImageContext();
     return image;
 }

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Are you using ARC? The problem here is that you don't have a reference to the UIColor object that you're trying to apply; the CGColor is backed by that UIColor, but ARC will deallocate the UIColor before you have a chance to use the CGColor.

The clearest solution is to have a local variable pointing to your UIColor with the objc_precise_lifetime attribute.

You can read more about this exact case on this article about UIColor and short ARC lifetimes or get more details about the objc_precise_lifetime attribute.

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Add the dots to all values:

[[UIColor colorWithRed:222./255. green:227./255. blue: 229./255. alpha:1] CGColor]) ;

Otherwise, you are dividing float by int.

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I suppose that 255 in 227./255 is perceived as an integer and divide is always return 0

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Your code works fine. You can verify the RGB colors with Iconfactory's xScope. Just compare it to [UIColor whiteColor].

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CGContextSetFillColorWithColor(context,[[UIColor colorWithRed:(255/255.f) green:(0/255.f) blue: (0/255.f) alpha:1] CGColor]);

참고URL : https://stackoverflow.com/questions/6496441/creating-a-uiimage-from-a-uicolor-to-use-as-a-background-image-for-uibutton