截屏存图片到相册或者指定路径

#import <QuartzCore/QuartzCore.h>

UIGraphicsBeginImageContext(currentView.bounds.size); //currentView当前的view

[currentView.layer renderInContext:UIGraphicsGetCurrentContext()];

UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);

存入到指定路径用以下方法：

- (BOOL)writeImage:(UIImage*)image toFileAtPath:(NSString*)aPath
{
    if ((image == nil) || (aPath == nil) || ([aPath isEqualToString:@""]))
        return NO;
    @try
    {
        
        NSData *imageData = nil;
        NSString *ext = [aPath pathExtension];
        if ([ext isEqualToString:@"png"])
        {
            imageData = UIImagePNGRepresentation(image); 
        }
        else 
        {
            // the rest, we write to jpeg
            
            // 0. best, 1. lost. about compress.
            
            imageData = UIImageJPEGRepresentation(image, 0);     
            
        }
     
        if ((imageData == nil) || ([imageData length] <= 0))
            return NO;
        
        [imageData writeToFile:aPath atomically:YES];       
        return YES;
    }
    @catch (NSException *e) 
    {
        NSLog(@"create thumbnail exception.");
    }
    return NO;
}