绘制image

最新推荐文章于 2024-04-26 20:33:55 发布

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本文介绍了一种在iOS开发中使用UIColor创建UIImage的方法。通过自定义的类别扩展，可以指定颜色和大小来生成UIImage，这在需要创建纯色背景图片的场景下非常实用。文章提供了详细的代码实现，包括如何设置颜色填充、获取当前上下文、结束图像上下文等关键步骤。

iOS绘制image图片

#import <UIKit/UIKit.h>

@interface UIImage (Color)

+ (UIImage *) ly_imageWithColor:(UIColor *)color;

+ (UIImage *) ly_imageWithColor:(UIColor *)color Size:(CGSize)size;

- (UIImage *) ly_stretched;

@end

#import "UIImage+Color.h"

@implementation UIImage (Color)

+ (UIImage *) ly_imageWithColor:(UIColor *)color {
    return [UIImage ly_imageWithColor:color Size:CGSizeMake(4.0f, 4.0f)];
}

+ (UIImage *) ly_imageWithColor:(UIColor *)color Size:(CGSize)size
{
    CGRect rect = CGRectMake(0.0f, 0.0f, size.width, size.height);
    UIGraphicsBeginImageContext(size);
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return [image ly_stretched];
}

- (UIImage *) ly_stretched
{
    CGSize size = self.size;

    UIEdgeInsets insets = UIEdgeInsetsMake(truncf(size.height-1)/2, truncf(size.width-1)/2, truncf(size.height-1)/2, truncf(size.width-1)/2);

    return [self resizableImageWithCapInsets:insets];
}

@end