iOS屏幕截屏

大家都知道通过同时按iphone和ipad关机键和home键可以进行截图，也可以通过代码编程进行对屏幕的截图。


使用opengles截图并保存代码：
-(UIImage *) glToUIImage {
    NSInteger myDataLength = 1024 * 768 * 4;
    
    // allocate array and read pixels into it.
    GLubyte *buffer = (GLubyte *) malloc(myDataLength);
    glReadPixels(0, 0, 1024, 768, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
    
    // gl renders "upside down" so swap top to bottom into new array.
    // there's gotta be a better way, but this works.
    GLubyte *buffer2 = (GLubyte *) malloc(myDataLength);
    for(int y = 0; y <768; y++)
    {
        for(int x = 0; x <1024 * 4; x++)
        {
            buffer2[(767 - y) * 1024 * 4 + x] = buffer[y * 4 * 1024 + x];
        }
    }
    
    // make data provider with data.
    CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, buffer2, myDataLength, NULL);
    
    // prep the ingredients
    int bitsPerComponent = 8;
    int bitsPerPixel = 32;
    int bytesPerRow = 4 * 1024;
    CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
    CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;
    CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;
    
    // make the cgimage
    CGImageRef imageRef = CGImageCreate(1024, 768, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);
    
    // then make the uiimage from that
    UIImage *myImage = [UIImage imageWithCGImage:imageRef];
    return myImage;
}


-(void)captureToPhotoAlbum {
    UIImage *image = [self glToUIImage];
    UIImageWriteToSavedPhotosAlbum(image, self, nil, nil);
}


使用苹果官网截图并保存


-(void)ScreenShots
{
    [self unschedule:@selector(ScreenShots)];
    
    CGSize imageSize = [[UIScreen mainScreen] bounds].size;
    if (NULL != UIGraphicsBeginImageContextWithOptions) {
        UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0);
    }
    else
    {
        UIGraphicsBeginImageContext(imageSize);
    }
    
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    for (UIWindow * window in [[UIApplication sharedApplication] windows]) {
        if (![window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen]) {
            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);
            [[window layer] renderInContext:context];
            
            CGContextRestoreGState(context);
        }
    }
    
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    NSThread *thread=[[NSThread alloc] initWithTarget:self selector:@selector(saveThread:) object:image];
    [thread start];
    [thread release];
  
    NSLog(@"Suceeded!");
}


-(void)saveThread:(UIImage*)image
{
    NSAutoreleasePool *pool=[[NSAutoreleasePool alloc]init];
    UIImageWriteToSavedPhotosAlbum(image, self, nil, nil);
    [pool release];
}