iOS

推荐一个第三方好用的框架：SDScreenshotCapture 

#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)  

一、全屏截图

UIImage *getImageWithFullScreenshot(void)  
{  
    // Source (Under MIT License): https://github.com/shinydevelopment/SDScreenshotCapture/blob/master/SDScreenshotCapture/SDScreenshotCapture.m#L35  
      
    BOOL ignoreOrientation = SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"8.0");  
      
    UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;  
      
    CGSize imageSize = CGSizeZero;  
    if (UIInterfaceOrientationIsPortrait(orientation) || ignoreOrientation)  
        imageSize = [UIScreen mainScreen].bounds.size;  
    else  
        imageSize = CGSizeMake([UIScreen mainScreen].bounds.size.height, [UIScreen mainScreen].bounds.size.width);  
      
    UIGraphicsBeginImageContextWithOptions(imageSize, NO, [UIScreen mainScreen].scale);  
    CGContextRef context = UIGraphicsGetCurrentContext();  
      
    for (UIWindow *window in [[UIApplication sharedApplication] windows])  
    {  
        CGContextSaveGState(context);  
        CGContextTranslateCTM(context, window.center.x, window.center.y);  
        CGContextConcatCTM(context, window.transform);  
        CGContextTranslateCTM(context, -window.bounds.size.width * window.layer.anchorPoint.x, -window.bounds.size.height * window.layer.anchorPoint.y);  
          
        // Correct for the screen orientation  
        if(!ignoreOrientation)  
        {  
            if(orientation == UIInterfaceOrientationLandscapeLeft)  
            {  
                CGContextRotateCTM(context, (CGFloat)M_PI_2);  
                CGContextTranslateCTM(context, 0, -imageSize.width);  
            }  
            else if(orientation == UIInterfaceOrientationLandscapeRight)  
            {  
                CGContextRotateCTM(context, (CGFloat)-M_PI_2);  
                CGContextTranslateCTM(context, -imageSize.height, 0);  
            }  
            else if(orientation == UIInterfaceOrientationPortraitUpsideDown)  
            {  
                CGContextRotateCTM(context, (CGFloat)M_PI);  
                CGContextTranslateCTM(context, -imageSize.width, -imageSize.height);  
            }  
        }  
          
        if([window respondsToSelector:@selector(drawViewHierarchyInRect:afterScreenUpdates:)])  
            [window drawViewHierarchyInRect:window.bounds afterScreenUpdates:NO];  
        else  
            [window.layer renderInContext:UIGraphicsGetCurrentContext()];  
          
        CGContextRestoreGState(context);  
    }  
      
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();  
      
    UIGraphicsEndImageContext();  
      
    return image;  
}  

 

二、修改部分区域截图

以下代码是UIWindow的Category

h文件

#import <UIKit/UIKit.h>  
  
@interface UIWindow (Category)  
  
- (UIImage *)screenshot;  
- (UIImage *)screenshotWithRect:(CGRect)rect;  
  
@end  

m文件

#import "UIWindow+Category.h"  
  
@implementation UIWindow (Category)  
  
- (UIImage *)screenshot  
{  
    return [self screenshotWithRect:self.bounds];  
}  
  
- (UIImage *)screenshotWithRect:(CGRect)rect  
{  
    // Source (Under MIT License): https://github.com/shinydevelopment/SDScreenshotCapture/blob/master/SDScreenshotCapture/SDScreenshotCapture.m#L35  
      
    BOOL ignoreOrientation = SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"8.0");  
      
    UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;  
      
    CGSize imageSize = CGSizeZero;  
    CGFloat width = rect.size.width, height = rect.size.height;  
    CGFloat x = rect.origin.x, y = rect.origin.y;  
      
//    imageSize = CGSizeMake(width, height);  
//    UIGraphicsBeginImageContextWithOptions(imageSize, NO, [UIScreen mainScreen].scale);  
    if (UIInterfaceOrientationIsPortrait(orientation) || ignoreOrientation)  
    {  
        //imageSize = [UIScreen mainScreen].bounds.size;  
        imageSize = CGSizeMake(width, height);  
        x = rect.origin.x, y = rect.origin.y;  
    }  
    else  
    {  
        //imageSize = CGSizeMake([UIScreen mainScreen].bounds.size.height, [UIScreen mainScreen].bounds.size.width);  
        imageSize = CGSizeMake(height, width);  
        x = rect.origin.y, y = rect.origin.x;  
    }  
      
    UIGraphicsBeginImageContextWithOptions(imageSize, NO, [UIScreen mainScreen].scale);  
    CGContextRef context = UIGraphicsGetCurrentContext();  
    CGContextSaveGState(context);  
    CGContextTranslateCTM(context, self.center.x, self.center.y);  
    CGContextConcatCTM(context, self.transform);  
    CGContextTranslateCTM(context, -self.bounds.size.width * self.layer.anchorPoint.x, -self.bounds.size.height * self.layer.anchorPoint.y);  
      
    // Correct for the screen orientation  
    if(!ignoreOrientation)  
    {  
        if(orientation == UIInterfaceOrientationLandscapeLeft)  
        {  
            CGContextRotateCTM(context, (CGFloat)M_PI_2);  
            CGContextTranslateCTM(context, 0, -self.bounds.size.height);  
            CGContextTranslateCTM(context, -x, y);  
        }  
        else if(orientation == UIInterfaceOrientationLandscapeRight)  
        {  
            CGContextRotateCTM(context, (CGFloat)-M_PI_2);  
            CGContextTranslateCTM(context, -self.bounds.size.width, 0);  
            CGContextTranslateCTM(context, x, -y);  
        }  
        else if(orientation == UIInterfaceOrientationPortraitUpsideDown)  
        {  
            CGContextRotateCTM(context, (CGFloat)M_PI);  
            CGContextTranslateCTM(context, -self.bounds.size.height, -self.bounds.size.width);  
            CGContextTranslateCTM(context, x, y);  
        }  
        else  
        {  
            CGContextTranslateCTM(context, -x, -y);  
        }  
    }  
    else  
    {  
        CGContextTranslateCTM(context, -x, -y);  
    }  
      
    //[self layoutIfNeeded];  
      
    if([self respondsToSelector:@selector(drawViewHierarchyInRect:afterScreenUpdates:)])  
        [self drawViewHierarchyInRect:self.bounds afterScreenUpdates:NO];  
    else  
        [self.layer renderInContext:UIGraphicsGetCurrentContext()];  
      
    CGContextRestoreGState(context);  
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();  
    UIGraphicsEndImageContext();  
      
    return image;  
}  
  
@end  

注意：此代码在旋转后，裁剪区域是相对左上角为原点旋转的，一般使用不到旋转情况

View截图

h文件

@interface UIView (Screenshot)  
- (UIImage *)screenshot;  
- (UIImage *)screenshotWithRect:(CGRect)rect;  
@end  

m文件

@implementation UIView (Screenshot)  
  
- (UIImage *)screenshot  
{  
    return [self screenshotWithRect:self.bounds];  
}  
  
- (UIImage *)screenshotWithRect:(CGRect)rect;  
{  
    UIGraphicsBeginImageContextWithOptions(rect.size, NO, [UIScreen mainScreen].scale);  
  
    CGContextRef context = UIGraphicsGetCurrentContext();  
    if (context == NULL)  
    {  
        return nil;  
    }  
    CGContextSaveGState(context);  
    CGContextTranslateCTM(context, -rect.origin.x, -rect.origin.y);  
      
    //[self layoutIfNeeded];  
  
    if( [self respondsToSelector:@selector(drawViewHierarchyInRect:afterScreenUpdates:)])  
    {  
        [self drawViewHierarchyInRect:self.bounds afterScreenUpdates:NO];  
    }  
    else  
    {  
        [self.layer renderInContext:context];  
    }  
      
    CGContextRestoreGState(context);  
  
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();  
    UIGraphicsEndImageContext();  
      
//    NSData *imageData = UIImageJPEGRepresentation(image, 1); // convert to jpeg  
//    image = [UIImage imageWithData:imageData scale:[UIScreen mainScreen].scale];  
      
    return image;  
}