手写一个二维码分享

生成一个二维码的小demo,只需要传入url网址就行了.

- (UIImage*)getImageWith:(NSString*)url{

// 1、创建滤镜对象

CIFilter*filter = [CIFilterfilterWithName:@"CIQRCodeGenerator"];

//恢复滤镜的默认属性

[filtersetDefaults];

// 2、设置数据

NSString*string_data = url;

//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 = [string_datadataUsingEncoding:NSUTF8StringEncoding];

//设置过滤器的输入值, KVC赋值

[filtersetValue:qrImageDataforKey:@"inputMessage"];

// 3、获得滤镜输出的图像

CIImage*outputImage = [filteroutputImage];

//图片小于(27,27),我们需要放大

outputImage = [outputImageimageByApplyingTransform:CGAffineTransformMakeScale(20,20)];

// 4、将CIImage类型转成UIImage类型

UIImage*start_image = [UIImageimageWithCIImage:outputImage];

// - - - - - - - - - - - - - - - -添加中间小图标- - - - - - - - - - - - - - - -

// 5、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(start_image.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

[start_imagedrawInRect:CGRectMake(0,0, start_image.size.width, start_image.size.height)];

//再把小图片画上去

NSString*icon_imageName =@"520";

UIImage*icon_image = [UIImageimageNamed:icon_imageName];

CGFloaticon_imageW =200;

CGFloaticon_imageH = icon_imageW;

CGFloaticon_imageX = (start_image.size.width- icon_imageW) *0.5;

CGFloaticon_imageY = (start_image.size.height- icon_imageH) *0.5;

[icon_imagedrawInRect:CGRectMake(icon_imageX, icon_imageY, icon_imageW, icon_imageH)];

// 6、获取当前画得的这张图片

UIImage*final_image =UIGraphicsGetImageFromCurrentImageContext();

// 7、关闭图形上下文

UIGraphicsEndImageContext();

// 8、借助UIImageView显示二维码

return_qrCodeImage.image= final_image;

//CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];

//NSData *data = [url dataUsingEncoding:NSUTF8StringEncoding];

//[filter setValue:data forKey:@"inputMessage"];

//CIImage *outImage = filter.outputImage;

//CIContext *context = [CIContext contextWithOptions:nil];

//CGRect extent = outImage.extent;

//CGImageRef bitmapImage = [context createCGImage:outImage fromRect:extent];

//CGFloat scale = MIN(250/CGRectGetWidth(extent), 250/CGRectGetHeight(extent));

//CGContextRef bitmapRef = CGBitmapContextCreate(nil, 250, 250, 8, 0, CGColorSpaceCreateDeviceGray(), (CGBitmapInfo)kCGImageAlphaNone);

//CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);

//CGContextScaleCTM(bitmapRef, scale, scale);

//CGContextDrawImage(bitmapRef, extent, bitmapImage);

//CGImageRef scaleImage = CGBitmapContextCreateImage(bitmapRef);

//CGContextRelease(bitmapRef);

//CGImageRelease(bitmapImage);

//return _qrCodeImage.image = [UIImage imageWithCGImage:scaleImage];

}

最后运行结果如下图: