有图片的二维码生成

NSArray *filters = [CIFilter filterNamesInCategory:kCICategoryBuiltIn];

NSLog(@"%@",filters);

//二维码过滤器

CIFilter *qrImageFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];

//设置过滤器默认属性

[qrImageFilter setDefaults];

//将字符串转换成 NSdata (虽然二维码本质上是 字符串,但是这里需要转换,不转换就崩溃)

NSData *qrImageData = [@"看看这是什么,shenm" dataUsingEncoding:NSUTF8StringEncoding];

//我们可以打印,看过滤器的 输入属性.这样我们才知道给谁赋值

NSLog(@"%@",qrImageFilter.inputKeys);

/*

inputMessage,        //二维码输入信息

inputCorrectionLevel //二维码错误的等级,就是容错率

*/

//设置过滤器的输入值  ,KVC赋值

[qrImageFilter setValue:qrImageData forKey:@"inputMessage"];

//取出图片

CIImage *qrImage = [qrImageFilter outputImage];

//但是图片 发现有的小 (27,27),我们需要放大..我们进去CIImage 内部看属性

qrImage = [qrImage imageByApplyingTransform:CGAffineTransformMakeScale(10, 10)];

//转成 UI的 类型

UIImage *qrUIImage = [UIImage imageWithCIImage:qrImage];

//----------------给 二维码 中间增加一个 自定义图片----------------

//开启绘图,获取图形上下文  (上下文的大小,就是二维码的大小)

UIGraphicsBeginImageContext(qrUIImage.size);

//把二维码图片画上去. (这里是以,图形上下文,左上角为 (0,0)点)

[qrUIImage drawInRect:CGRectMake(0, 0, qrUIImage.size.width, qrUIImage.size.height)];

//再把小图片画上去

UIImage *sImage = [UIImage imageNamed:@"麦稻首页4"];

//

//    UIImageView *sImageView = [[UIImageView alloc]initWithFrame:CGRectMake(50, 50, 60, 60)];

//    [self.view addSubview:sImageView];

//    sImageView.image = sImage;

//    // 类似于clip，使用masksToBounds阴影效果无效

//    sImageView.layer.masksToBounds = YES;

//    //图层的圆角半径

//    sImageView.layer.cornerRadius = 50;

CGFloat sImageW = 100;

CGFloat sImageH= sImageW;

CGFloat sImageX = (qrUIImage.size.width - sImageW) * 0.5;

CGFloat sImgaeY = (qrUIImage.size.height - sImageH) * 0.5;

[sImage drawInRect:CGRectMake(sImageX, sImgaeY, sImageW, sImageH)];

//获取当前画得的这张图片

UIImage *finalyImage = UIGraphicsGetImageFromCurrentImageContext();

//关闭图形上下文

UIGraphicsEndImageContext();

//设置图片

self.erweimaImageView.image = finalyImage;