一：生成二维码
1.根据一个字符串生成一个二维码 根据
#import <CoreImage/CoreImage.h>这个框架写的
在按钮的点击事件写
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *imv; @end
// 1. 实例化二维码滤镜
CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"]; // 2. 恢复滤镜的默认属性
[filter setDefaults]; // 3. 将字符串转换成NSData
NSData *data = [@"http://www.baidu.com" dataUsingEncoding:NSUTF8StringEncoding]; // 4. 通过KVO设置滤镜inputMessage数据
[filter setValue:data forKey:@"inputMessage"];
// 5. 获得滤镜输出的图像
CIImage *outputImage = [filter outputImage];
UIImage *i = [UIImage imageWithCIImage:outputImage]; // 6. 将CIImage转换成UIImage，并放大显示
self.imv.image = i;
2.此时 就根据你写的字符串 会 生成一个对应的二维码了 但是有点模糊有没有 ？？
解决的方法来啦
//7.把图片变的更清晰
CGRect extent = CGRectIntegral(outputImage.extent);
CGFloat size = 100;
CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent)); // 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:outputImage fromRect:extent];
CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
CGContextScaleCTM(bitmapRef, scale, scale);
CGContextDrawImage(bitmapRef, extent, bitmapImage); // 保存bitmap到图片
CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
CGContextRelease(bitmapRef);
CGImageRelease(bitmapImage);
UIImage *i = [UIImage imageWithCGImage:scaledImage];
清晰的有没有，^O^
3.微信的二维码名片是不是有自己的logo哇，怎么弄捏
UIImage *logoImage = [UIImage imageNamed:@"1111.png"];
UIView *QRCodeView = [[UIView alloc] init];
QRCodeView.frame = CGRectMake(0, 0, 100 , 100);
if (logoImage != nil) {
// 增加logo
i = [self addImageToSuperImage:i withSubImage:logoImage andSubImagePosition:CGRectMake(20, 20, 20, 20)];
}
QRCodeView.layer.contents = (__bridge id)i.CGImage;
这样就可以加上logo了
二：扫描二维码
用
#import <AVFoundation/AVFoundation.h>这个框架写
@interface ViewController ()<AVCaptureMetadataOutputObjectsDelegate>
@property(nonatomic,strong)AVCaptureSession *session;
@property(nonatomic,strong)AVCaptureVideoPreviewLayer *previewLayer;
@end
- (void)viewDidLoad {
[super viewDidLoad];
// 1. 实例化拍摄设备
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
// 2. 设置输入设备
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
// 3. 设置元数据输出
// 3.1 实例化拍摄元数据输出
AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
// 3.3 设置输出数据代理
[output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
// 4. 添加拍摄会话
// 4.1 实例化拍摄会话
AVCaptureSession *session = [[AVCaptureSession alloc] init];
// 4.2 添加会话输入
[session addInput:input];
// 4.3 添加会话输出
[session addOutput:output];
// 4.3 设置输出数据类型，需要将元数据输出添加到会话后，才能指定元数据类型，否则会报错
[output setMetadataObjectTypes:@[AVMetadataObjectTypeQRCode]];
self.session = session;
// 5. 视频预览图层
// 5.1 实例化预览图层, 传递_session是为了告诉图层将来显示什么内容
AVCaptureVideoPreviewLayer *preview = [AVCaptureVideoPreviewLayer layerWithSession:_session];
preview.videoGravity = AVLayerVideoGravityResizeAspectFill;
preview.frame = self.view.bounds;
// 5.2 将图层插入当前视图
[self.view.layer insertSublayer:preview atIndex:100];
self.previewLayer = preview;
// 6. 启动会话
[_session startRunning];
}
代理方法
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
// 会频繁的扫描，调用代理方法
// 1. 如果扫描完成，停止会话
[self.session stopRunning];
// 2. 删除预览图层
[self.previewLayer removeFromSuperlayer]; NSLog(@"%@", metadataObjects);
// 3. 设置界面显示扫描结果 if (metadataObjects.count > 0) {
AVMetadataMachineReadableCodeObject *obj = metadataObjects[0];
// 提示：如果需要对url或者名片等信息进行扫描，可以在此进行扩展！
// _label.text = obj.stringValue;
NSLog(@"%@", obj.stringValue);
} }
三：最后封装了一下生成二维码的代码 代价可以直接用
-(UIImage *)superCIImageWith:(NSString*)urlString andSuperSize:(CGFloat)puserSize andlogoImage:(UIImage *)logoImage andLogoImageLocation:(CGRect)rect
{
// 1. 实例化二维码滤镜
CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
// 2. 恢复滤镜的默认属性
[filter setDefaults]; // 3. 将字符串转换成NSData
NSData *data = [urlString dataUsingEncoding:NSUTF8StringEncoding]; // 4. 通过KVO设置滤镜inputMessage数据
[filter setValue:data forKey:@"inputMessage"]; // 5. 获得滤镜输出的图像
CIImage *outputImage = [filter outputImage]; // UIImage *i = [UIImage imageWithCIImage:outputImage];
// 6. 将CIImage转换成UIImage，并放大显示 //7.把图片变的更清晰
CGRect extent = CGRectIntegral(outputImage.extent);
CGFloat scale = MIN(puserSize/CGRectGetWidth(extent), puserSize/CGRectGetHeight(extent)); // 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:outputImage fromRect:extent];
CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
CGContextScaleCTM(bitmapRef, scale, scale);
CGContextDrawImage(bitmapRef, extent, bitmapImage); // 保存bitmap到图片
CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
CGContextRelease(bitmapRef);
CGImageRelease(bitmapImage);
UIImage *i = [UIImage imageWithCGImage:scaledImage]; UIView *QRCodeView = [[UIView alloc] init];
QRCodeView.frame = CGRectMake(0, 0, 400 , 400); if (logoImage != nil) {
// 增加logo
i = [self addImageToSuperImage:i withSubImage:logoImage andSubImagePosition:rect];
} QRCodeView.layer.contents = (__bridge id)i.CGImage;
return i; }