iOS开发之,如何截图and如何合并多张图片等...

 　　1、UIView截图

　　-(UIImage*)captureView:(UIView *)theView{

　　CGRect rect = theView.frame;

　　if ([theView isKindOfClass:[UIScrollView class]]) {

　　rect.size = ((UIScrollView *)theView).contentSize;

　　}

　　UIGraphicsBeginImageContext(rect.size);

　　CGContextRef context = UIGraphicsGetCurrentContext();

　　[theView.layer renderInContext:context];

　　UIImage *img = UIGraphicsGetImageFromCurrentImageContext();

　　UIGraphicsEndImageContext();

　　return img;

　　2、UIScrollview截图

　　- (UIImage *)captureScrollView:(UIScrollView *)scrollView{

　　UIImage* image = nil;

　　UIGraphicsBeginImageContext(scrollView.contentSize);

　　{

　　CGPoint savedContentOffset = scrollView.contentOffset;

　　CGRect savedFrame = scrollView.frame;

　　scrollView.contentOffset = CGPointZero;

　　scrollView.frame = CGRectMake(0, 0, scrollView.contentSize.width, scrollView.contentSize.height);

　　[scrollView.layer renderInContext: UIGraphicsGetCurrentContext()];

　　image = UIGraphicsGetImageFromCurrentImageContext();

　　scrollView.contentOffset = savedContentOffset;

　　scrollView.frame = savedFrame;

　　}

　　UIGraphicsEndImageContext();

　　if (image != nil) {

　　return image;

　　}

　　return nil;

　　}

　　3、合并多张图片

　　- (UIImage *)composeWithHeader:(UIImage *)header content:(UIImage *)content footer:(UIImage *)footer{

　　CGSize size = CGSizeMake(content.size.width, header.size.height +content.size.height +footer.size.height);

　　UIGraphicsBeginImageContext(size);

　　[header drawInRect:CGRectMake(0,

　　0,

　　header.size.width,

　　header.size.height)];

　　[content drawInRect:CGRectMake(0,

　　header.size.height,

　　content.size.width,

　　content.size.height)];

　　[footer drawInRect:CGRectMake(0,

　　header.size.height+content.size.height,

　　footer.size.width,

　　footer.size.height)];

　　UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

　　UIGraphicsEndImageContext();

　　return image;

　　}

　　4、流媒体

　　将音频、图片转成base64Binary

　　+(NSData *)base64Encoded:(NSData *)data

　　{

　　//base64binary(流媒体)

　　static char encodingTable[64] = {

　　'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',

　　'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',

　　'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',

　　'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/' };

　　const unsigned char *bytes = [data bytes];

　　NSMutableString *result = [NSMutableString stringWithCapacity:[data length]];