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点击二维码，将生成的二维码保存到相册（由于图片违规所以对二维码进行擦出） 
UI编写就不放入文章中了，只书写主要方法，demo放在这里了。 1、生成二维码 调用方法 UIImage *qrcodeImg = [self getQRCodeWithContentTxt:_textField.text codeWidth:600 picImg:[UIImage imageNamed:@"img"]]; _QRCodeImage.image = qrcodeImg;生成二维码的函数 - (UIImage*)getQRCodeWithContentTxt:(NSString*)urlString codeWidth:(CGFloat)codeWidth picImg:(UIImage*)picImg{ //使用名为 CIQRCodeGenerator 的过滤器创建一个CIFilter对象 CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"]; [filter setDefaults]; NSData *data = [urlString dataUsingEncoding:NSUTF8StringEncoding]; //通过kvo方式给一个字符串，生成二维码 [filter setValue:data forKey:@"inputMessage"]; //含文本信息的二维码已经生成 CIImage *filterImg = [filter outputImage]; CIImage *imageOri = [CIImage imageWithCGImage:[self filterQRCodeWithCIImage:filterImg codeWidth:codeWidth].CGImage]; UIImage *img = [UIImage imageWithCIImage:imageOri];//默认二维码 //------------------------------------------------------ //-------对二维码增添颜色，不需要的可以跳过---------- CIFilter* color_filter = [CIFilter filterWithName:@"CIFalseColor"]; [color_filter setDefaults]; [color_filter setValue:imageOri forKey:@"inputImage"]; //设置二维码的颜色（二维码都是由2个颜色组成，可自行改变尝试效果） [color_filter setValue:[CIColor colorWithRed:66/255.0 green:147/255.0 blue:82/255.0] forKey:@"inputColor0"]; [color_filter setValue:[CIColor clearColor]forKey:@"inputColor1"]; CIImage *colorImage = [color_filter outputImage]; img = [UIImage imageWithCIImage:colorImage];//修改颜色的二维码 //-------对二维码增添颜色，不需要的可以跳过---------- //------------------------------------------------------ //开启图形上下文(会变模糊) //UIGraphicsBeginImageContext(img.size); //开启图形上下文(防止虚化模糊) UIGraphicsBeginImageContextWithOptions(img.size,NO,[[UIScreen mainScreen]scale]); //将二维码的图片画入 [img drawInRect:CGRectMake(0, 0, img.size.width, img.size.height)]; //------------------------------------------------------ //-------二维码中间插入小插图，不需要的可以跳过---------- UIImage *centerImg = picImg; CGFloat centerW = img.size.width*0.2; CGFloat centerH = centerW; CGFloat centerX = (img.size.width-centerW)*0.5; CGFloat centerY = (img.size.height-centerH)*0.5; [centerImg drawInRect:CGRectMake(centerX, centerY, centerW, centerH)]; //-------二维码中间插入小插图，不需要的可以跳过---------- //------------------------------------------------------ //5.3获取绘制好的图片 UIImage *finalImg = UIGraphicsGetImageFromCurrentImageContext(); //5.4关闭图像上下文 UIGraphicsEndImageContext(); return finalImg; } - (UIImage *)filterQRCodeWithCIImage:(CIImage *)image codeWidth:(CGFloat)codeWidth{ CGRect extent = CGRectIntegral(image.extent); CGFloat scale = MIN(codeWidth/CGRectGetWidth(extent), codeWidth/CGRectGetHeight(extent)); // 1.创建bitmap; size_t width = CGRectGetWidth(extent) * scale; size_t height = CGRectGetHeight(extent) * scale; CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray(); CGContextRef bitmapRef =CGBitmapContextCreate(nil, width, height,8,0, cs, (CGBitmapInfo)kCGImageAlphaNone); CIContext*context = [CIContext contextWithOptions:nil]; CGImageRef bitmapImage = [context createCGImage:image fromRect:extent]; CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone); CGContextScaleCTM(bitmapRef, scale, scale); CGContextDrawImage(bitmapRef, extent, bitmapImage); // 2.保存bitmap到图片 CGImageRef scaledImage =CGBitmapContextCreateImage(bitmapRef); CGContextRelease(bitmapRef); CGImageRelease(bitmapImage); return [UIImage imageWithCGImage:scaledImage]; }2、添加提示框 写在UIViewController中 // 添加提示框 UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Save QRCode?" message:@"The QRCode will be saved in Camera Roll album." preferredStyle:UIAlertControllerStyleAlert]; UIAlertAction *saveAction = [UIAlertAction actionWithTitle:@"Save" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) { // 保存二维码图像 [self saveQRCodeImage]; }]; UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:nil]; [alertController addAction:saveAction]; [alertController addAction:cancelAction]; [self presentViewController:alertController animated:YES completion:nil];3、保存图片到相册 要提前info.plist文件中写入访问相册的权限，否则程序会崩溃报错 
- (void)saveQRCodeImage {
// 保存图像,需要提前在info.plist文件中写入访问相册的权限,否则会报错
// UIImageWriteToSavedPhotosAlbum(_QRCodeView.QRCodeImage.image, nil, nil, nil);
UIImageWriteToSavedPhotosAlbum(_QRCodeView.QRCodeImage.image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
}
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
NSString *title;
NSString *message;
if (!error) {
title = @"Success!";
message = @"The QRCode image saved successfully.";
}
else {
title = @"Failed!";
message = @"The QRCode image saved unsuccessfully, please try again later.";
}
// 使用alert view显示二维码保存状态
UIAlertController *alert = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *action = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil];
[alert addAction:action];
[self presentViewController:alert animated:YES completion:nil];
}
@end
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