iOS绘制image图片

首先为UIImage新建一个类别
代码如下：
.h文件

#import <UIKit/UIKit.h>

@interface UIImage (Color)

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

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

- (UIImage *) ly_stretched;

@end

.m文件

#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

然后就可以在其他地方使用了