iOS使用代码截图

// 从view上截图  
- (UIImage *)getImage {  

    UIGraphicsBeginImageContextWithOptions(CGSizeMake(150, 150), NO, 1.0);  //NO，YES 控制是否透明  
    [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];  
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();  
    UIGraphicsEndImageContext();  
    // 生成后的image  

    return image;  
}  

// 根据给定得图片，从其指定区域截取一张新得图片  
-(UIImage *)getImageFromImage{  
    //大图bigImage  
    //定义myImageRect，截图的区域  
    CGRect myImageRect = CGRectMake(70, 10, 150, 150);  
    UIImage* bigImage= [UIImage imageNamed:@"mm.jpg"];  
    CGImageRef imageRef = bigImage.CGImage;  
    CGImageRef subImageRef = CGImageCreateWithImageInRect(imageRef, myImageRect);  
    CGSize size;  
    size.width = 150;  
    size.height = 150;  
    UIGraphicsBeginImageContext(size);  
    CGContextRef context = UIGraphicsGetCurrentContext();  
    CGContextDrawImage(context, myImageRect, subImageRef);  
    UIImage* smallImage = [UIImage imageWithCGImage:subImageRef];  
    UIGraphicsEndImageContext();  
    return smallImage;  
} 


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