UIImage的简单封装

1、颜色转图片

+ (UIImage *)imageWithColor:(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;
}

2、裁剪

#import 

@interface UIImage (Image)
+ (UIImage *)imageWithClipImage:(UIImage *)image borderWidth:(CGFloat)borderWidth borderColor:(UIColor *)color;
@end

#import "UIImage+Image.h"

@implementation UIImage (Image)
+ (UIImage *)imageWithClipImage:(UIImage *)image borderWidth:(CGFloat)borderWidth borderColor:(UIColor *)color {
    // 图片的宽度和高度
    CGFloat imageWH = image.size.width;
    // 设置圆环的宽度
    CGFloat border = borderWidth;
    // 圆形的宽度和高度
    CGFloat ovalWH = imageWH + 2 * border;
    // 1.开启上下文
    UIGraphicsBeginImageContextWithOptions(CGSizeMake(ovalWH, ovalWH), NO, 0);
    // 2.画大圆
    UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, ovalWH, ovalWH)];
    [color set];
    [path fill];
    // 3.设置裁剪区域
    UIBezierPath *clipPath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(border, border, imageWH, imageWH)];
    [clipPath addClip];
    // 4.绘制图片
    [image drawAtPoint:CGPointMake(border, border)];
    // 5.获取图片
    UIImage *clipImage = UIGraphicsGetImageFromCurrentImageContext();
    // 6.关闭上下文
    UIGraphicsEndImageContext();
    return clipImage;
}
@end

3、截屏

//.h
// 控件截屏
+ (UIImage *)imageWithCaputureView:(UIView *)view;

+ (UIImage *)imageWithCaputureView:(UIView *)view
{
    // 开启位图上下文
    UIGraphicsBeginImageContextWithOptions(view.bounds.size, NO, 0);

    // 获取上下文
    CGContextRef ctx = UIGraphicsGetCurrentContext();

    // 把控件上的图层渲染到上下文,layer只能渲染
    [view.layer renderInContext:ctx];

    // 生成一张图片
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    // 关闭上下文
    UIGraphicsEndImageContext();

    return image;
}