iOS开发-几种截屏方法

UIGraphicsBeginImageContextWithOptions(pageView.page.bounds.size, YES, zoomScale);
[pageView.page.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *uiImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

- (UIImage *) glToUIImage {
DWScrollView *pageView = [self getActivePageView];
pageView.page.backgroundColor = [UIColor clearColor];
// self.backgroundColor=[UIColor clearColor];
NSInteger myDataLength = 320 * 308 * 4;

// allocate array and read pixels into it.
GLubyte *buffer = (GLubyte *) malloc(myDataLength);
glReadPixels(0, 0, 320, 308, 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 <308; y++)
{
for(int x = 0; x <320 * 4; x++)
{
if(buffer[y* 4 * 320 + x]==0)
buffer2[(307 - y) * 320 * 4 + x]=1;
else
buffer2[(307 - y) * 320 * 4 + x] = buffer[y* 4 * 320 + 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 * 320;
CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;
CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;

// make the cgimage
CGImageRef
imageRef = CGImageCreate(320, 308, bitsPerComponent, bitsPerPixel,
bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO,
renderingIntent);

// then make the uiimage from that
UIImage *myImage = [UIImage imageWithCGImage:imageRef];
UIImageWriteToSavedPhotosAlbum(myImage, nil, nil, nil);
return myImage;
}

// get screen
- (void)grabScreen {
unsigned char buffer[320*480*4];
glReadPixels(0,0,320,480,GL_RGBA,GL_UNSIGNED_BYTE,&buffer);

CGDataProviderRef ref = CGDataProviderCreateWithData(NULL, &buffer, 320*480*4, NULL);
CGImageRef
iref =
CGImageCreate(320,480,8,32,320*4,CGColorSpaceCreateDeviceRGB(),kCGBitmapByteOrderDefault,ref,NULL,true,kCGRenderingIntentDefault);
CGFloat width = CGImageGetWidth(iref);
CGFloat height = CGImageGetHeight(iref);
size_t length = width*height*4;
uint32_t *pixels = (uint32_t *)malloc(length);
CGContextRef
context = CGBitmapContextCreate(pixels, width, height, 8, 320*4,
CGImageGetColorSpace(iref), kCGImageAlphaLast |
kCGBitmapByteOrder32Big);
CGContextTranslateCTM(context, 0.0, height);
CGContextScaleCTM(context, 1.0, -1.0);
CGContextDrawImage(context, CGRectMake(0.0, 0.0, width, height), iref);
CGImageRef outputRef = CGBitmapContextCreateImage(context);
UIImage *outputImage = [UIImage imageWithCGImage:outputRef];

UIImageWriteToSavedPhotosAlbum(outputImage, nil, nil, nil);

CGContextRelease(context);
CGImageRelease(iref);
CGDataProviderRelease(ref);
}

CGImageRef UIGetScreenImage();
void SaveScreenImage(NSString *path)
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
CGImageRef cgImage = UIGetScreenImage();
void *imageBytes = NULL;
if (cgImage == NULL) {
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
imageBytes = malloc(320 * 480 * 4);
CGContextRef
context = CGBitmapContextCreate(imageBytes, 320, 480, 8, 320 * 4,
colorspace, kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Big);
CGColorSpaceRelease(colorspace);
for (UIWindow *window in [[UIApplication sharedApplication] windows]) {
CGRect bounds = [window bounds];
CALayer *layer = [window layer];
CGContextSaveGState(context);
if ([layer contentsAreFlipped]) {
CGContextTranslateCTM(context, 0.0f, bounds.size.height);
CGContextScaleCTM(context, 1.0f, -1.0f);
}
[layer renderInContext:(CGContextRef)context];
CGContextRestoreGState(context);
}
cgImage = CGBitmapContextCreateImage(context);
CGContextRelease(context);
}
NSData *pngData = UIImagePNGRepresentation([UIImage imageWithCGImage:cgImage]);
CGImageRelease(cgImage);
if (imageBytes)
free(imageBytes);
[pngData writeToFile:path atomically:YES];
[pool release];
}

+ (UIImage *)imageWithScreenContents
{
CGImageRef cgScreen = UIGetScreenImage();
if (cgScreen) {
UIImage *result = [UIImage imageWithCGImage:cgScreen];
CGImageRelease(cgScreen);
return result;
}
return nil;
}

在程序中如何把两张图片合成为一张图片
- (UIImage *)addImage:(UIImage *)image1 toImage:(UIImage *)image2 {
UIGraphicsBeginImageContext(image1.size);

// Draw image1
[image1 drawInRect:CGRectMake(0, 0, image1.size.width, image1.size.height)];

// Draw image2
[image2 drawInRect:CGRectMake(0, 0, image2.size.width, image2.size.height)];

UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return resultingImage;
}