UIView+Screenshot.h

//
//  UIView+Screenshot.h
//
//  Created by manjun.han on 13-3-13.
//  Copyright (c) 2013年 com.hmj. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface UIView (Screenshot)

- (UIImage*)screenshot ;

@end

UIView+Screenshot.m

//
//  UIView+Screenshot.m
//
//  Created by manjun.han on 13-3-13.
//  Copyright (c) 2013年 com.hmj. All rights reserved.
//

#import "UIView+Screenshot.h"
#import <QuartzCore/QuartzCore.h>

@implementation UIView (Screenshot)

- (UIImage*)screenshot
{
    // 如果bitmap是彻底不透明的，设置opaque = YES，来优化bitmap的存储。貌似生成的bitmap会忽略alpha通道值
    UIGraphicsBeginImageContextWithOptions(self.bounds.size, YES, 0.0);
    
    CGContextRef ctx = UIGraphicsGetCurrentContext() ;
    
    [self.layer renderInContext:ctx];
    
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    
    return image;
}

@end