iOS原生二維碼處理

前期準備

#import <CoreImage/CoreImage.h>
#import <AssetsLibrary/AssetsLibrary.h>
#import <AVFoundation/AVFoundation.h>

@interface QRViewController ()<AVCaptureMetadataOutputObjectsDelegate>

@property (nonatomic, strong) UIImageView *QRimageV;

@property (strong,nonatomic)AVCaptureDevice * device;
@property (strong,nonatomic)AVCaptureDeviceInput * input;
@property (strong,nonatomic)AVCaptureMetadataOutput * output;
@property (strong,nonatomic)AVCaptureSession * session;
@property (strong,nonatomic)AVCaptureVideoPreviewLayer * preview;

@end

生成二維碼

//生成二維碼
- (void)getQRImage{
    //1.創建濾鏡
    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    //濾鏡回覆默認設置
    [filter setDefaults];


    //2.給濾鏡添加數據
    NSString *str = @"my name is WX";
    NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];
    [filter setValue:data forKeyPath:@"inputMessage"];//使用kvc形式給filter賦值

    //3.生成二維碼
    CIImage *image = [filter outputImage];

    //4.顯示二維碼
//    self.QRimageV.image = [UIImage imageWithCIImage:image]; //圖片會模糊
    self.QRimageV.image = [self createNonInterpolatedUIImageFormCIImage:image withSize:200];

}

處理二維碼圖片模糊問題

//處理二維碼不清晰問題
- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size {

    CGRect extent = CGRectIntegral(image.extent);

    //設置比例
    CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));

    // 創建bitmap（位圖）;
    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);

    // 保存bitmap到圖片
    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);

    CGContextRelease(bitmapRef);

    CGImageRelease(bitmapImage);

    return [UIImage imageWithCGImage:scaledImage];

}

保存二維碼圖片到本地

//保存圖片
- (void)saveImage:(UIImage *)image{
    __block ALAssetsLibrary *lib = [[ALAssetsLibrary alloc] init];
    [lib writeImageToSavedPhotosAlbum:image.CGImage metadata:nil completionBlock:^(NSURL *assetURL, NSError *error) {

        NSLog(@"assetURL = %@, error = %@", assetURL, error);
        lib = nil;

    }];

}

掃描二維碼

//掃描二維碼
- (void)scanQR{

    // Device
    _device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    // Input
    _input = [AVCaptureDeviceInput deviceInputWithDevice:self.device error:nil];

    // Output
    _output = [[AVCaptureMetadataOutput alloc]init];
    [_output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];

    // Session
    _session = [[AVCaptureSession alloc]init];
    [_session setSessionPreset:AVCaptureSessionPresetHigh];

    //連接輸入輸出
    if ([_session canAddInput:self.input])
    {
        [_session addInput:self.input];
    }

    if ([_session canAddOutput:self.output])
    {
        [_session addOutput:self.output];
    }


    //設置條形碼類型
    _output.metadataObjectTypes =@[AVMetadataObjectTypeQRCode];

    //添加掃描畫面
    _preview =[AVCaptureVideoPreviewLayer layerWithSession:_session];
    _preview.videoGravity =AVLayerVideoGravityResizeAspectFill;
    _preview.frame =self.view.layer.bounds;
    [self.view.layer insertSublayer:_preview atIndex:0];

    //開始掃面
    [_session startRunning];

}

實現掃描之後的代理方法

#pragma 實現掃描後的代理方法
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
    NSString *stringValue;
    if ([metadataObjects count] >0){
        //停止掃描
        [_session stopRunning];
        AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects objectAtIndex:0];
        stringValue = metadataObject.stringValue;

        NSLog(@"stringValue==%@",stringValue);  //二維碼中的內容
    }
}