iOS开发之将base64位编码的字符串转换为图片，data转图片，图片转data

一、将base64位编码的字符串转换为图片
self.captchaImage = [[UIImageView alloc]initWithFrame:CGRectMake(frameW -150, imageY + imageH + 160,100, 40)];
[self.view addSubview:self.captchaImage];
NSString *encodedImageStr = imageJson;

NSData *decodedImgData = [[NSData alloc] initWithBase64EncodedString:encodedImageStr options:NSDataBase64DecodingIgnoreUnknownCharacters];
UIImage *decodedImage = [UIImage imageWithData:decodedImgData];
self.captchaImage.image = decodedImage;

UIImage *image = [UIImage   imageNamed:@"1.png"];
NSData *data = UIImagePNGRepresentation(image);

NSData *data =UIImageJPEGRepresentation(image, 1.0);

NSString *encodedImgStr = [data base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];

UIImage *decodedImage = [UIImage imageWithData:data];