IOS生成二维码、扫二维码

有好多生成二维码以及扫二维码的第三方库，我这种方法是用系统自带的，他有个缺点就是生成的二维码太模糊，我这里进行了处理，遍历整个像素，对二维码进行颜色填充，使黑色加深

一、生成二维码

//1. 创建二维码滤镜
    CIFilter *filer = [CIFilter filterWithName:@"CIQRCodeGenerator"];

    //2.还原滤镜的初始设置
    [filer setDefaults];

    //3.将要隐藏在二维码中的字符串变成data
    NSData *data = [@"123456" dataUsingEncoding:NSUTF8StringEncoding];

    [filer setValue:data forKey:@"inputMessage"];

    //5.生成二维码
    CIImage *outputImage = [filer outputImage];
    UIImage *image=[self createNonInterpolatedUIImageFormCIImage:outputImage withSize:250.0f];
    //6.填充颜色后的二维码
    codeImage =[self imageBlackToTransparent:image];

下面两个方法是处理二维码颜色的

#pragma mark - 二维码图片
//返回需要大小的UIImage
- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size {
    CGRect extent = CGRectIntegral(image.extent);
    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:image fromRect:extent];
    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
    CGContextScaleCTM(bitmapRef, scale, scale);
    CGContextDrawImage(bitmapRef, extent, bitmapImage);
    // 保存bitmap到图片
    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
    return [UIImage imageWithCGImage:scaledImage];
}
void ProviderReleaseData (void *info, const void *data, size_t size){
    free((void*)data);
}
//对二维码进行颜色填充
- (UIImage*)imageBlackToTransparent:(UIImage*)image{
    const int imageWidth = image.size.width;
    const int imageHeight = image.size.height;
    size_t      bytesPerRow = imageWidth * 4;
    uint32_t* rgbImageBuf = (uint32_t*)malloc(bytesPerRow * imageHeight);
    // create context
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(rgbImageBuf, imageWidth, imageHeight, 8, bytesPerRow, colorSpace,
                                                 kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast);
    CGContextDrawImage(context, CGRectMake(0, 0, imageWidth, imageHeight), image.CGImage);
    // 输出图片
    CGDataProviderRef dataProvider = CGDataProviderCreateWithData(NULL, rgbImageBuf, bytesPerRow * imageHeight, ProviderReleaseData);
    CGImageRef imageRef = CGImageCreate(imageWidth, imageHeight, 8, 32, bytesPerRow, colorSpace,
                                        kCGImageAlphaLast | kCGBitmapByteOrder32Little, dataProvider,
                                        NULL, true, kCGRenderingIntentDefault);
    CGDataProviderRelease(dataProvider);
    UIImage* resultUIImage = [UIImage imageWithCGImage:imageRef];
    return resultUIImage;
}

运行效果：

中间的头像是叠在二维码上的，不会影响扫描结果，这里很简单就不共享代码了

二、扫二维码

导入#import
遵守协议

//
//  ScanQRCodeViewController.h
//  IM
//
//  Created by admin on 15/12/18.
//  Copyright © 2015年 ZBY. All rights reserved.
//

#import "BaseViewController.h"
#import 

@interface ScanQRCodeViewController : BaseViewController


@property (strong, nonatomic)  UIView *viewPreview;
@property (strong, nonatomic)  UILabel *lblStatus;
@property (strong, nonatomic)  UIButton *startBtn;

@property (strong, nonatomic) UIView *boxView;
@property (nonatomic) BOOL isReading;
@property (strong, nonatomic) CALayer *scanLayer;

-(BOOL)startReading;
-(void)stopReading;

//捕捉会话
@property (nonatomic, strong) AVCaptureSession *captureSession;
//展示layer
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *videoPreviewLayer;


@end

//
//  ScanQRCodeViewController.m
//  IM
//
//  Created by admin on 15/12/18.
//  Copyright © 2015年 ZBY. All rights reserved.
//

#import "ScanQRCodeViewController.h"
#import "AddContactsViewController.h"

#define SCANVIEW_EdgeTop 50.0
#define SCANVIEW_EdgeLeft 50.0

#define TINTCOLOR_ALPHA 0.4  //浅色透明度
#define DARKCOLOR_ALPHA 1  //深色透明度
@interface ScanQRCodeViewController ()

@end

@implementation ScanQRCodeViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    [self initBar:@"设置" titleName:@"扫描二维码"];

    _viewPreview = [[UIView alloc]initWithFrame:CGRectMake(0, 64, WIDTH, HEIGHT-204)];
    [self.view addSubview:_viewPreview];
    _startBtn = [[UIButton alloc] initWithFrame:CGRectMake(0, HEIGHT-140, WIDTH, 40)];
    [_startBtn setTitle:@"开始扫描" forState:UIControlStateNormal];
    _startBtn.backgroundColor = MYCOLOR;
    [_startBtn addTarget:self action:@selector(startStopReading:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:_startBtn];
    _lblStatus = [[UILabel alloc] initWithFrame:CGRectMake(10, HEIGHT-100, WIDTH-20, 100)];
    //_lblStatus.backgroundColor = [UIColor whiteColor];
    _lblStatus.numberOfLines = 0;
    _lblStatus.textAlignment = NSTextAlignmentCenter;
    _lblStatus.font = [UIFont systemFontOfSize:15];
    [self.view addSubview:_lblStatus];

    _captureSession = nil;
    _isReading = NO;

    [self startReading];
}

- (BOOL)startReading {
    NSError *error;
    //1.初始化捕捉设备（AVCaptureDevice），类型为AVMediaTypeVideo
    AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    //2.用captureDevice创建输入流
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error];
    if (!input) {
        NSLog(@"%@", [error localizedDescription]);
        return NO;
    }
    //3.创建媒体数据输出流
    AVCaptureMetadataOutput *captureMetadataOutput = [[AVCaptureMetadataOutput alloc] init];
    //4.实例化捕捉会话
    _captureSession = [[AVCaptureSession alloc] init];
    //4.1.将输入流添加到会话
    [_captureSession addInput:input];
    //4.2.将媒体输出流添加到会话中
    [_captureSession addOutput:captureMetadataOutput];
    //5.创建串行队列，并加媒体输出流添加到队列当中
    dispatch_queue_t dispatchQueue;
    dispatchQueue = dispatch_queue_create("myQueue", NULL);
    //5.1.设置代理
    [captureMetadataOutput setMetadataObjectsDelegate:self queue:dispatchQueue];
    //5.2.设置输出媒体数据类型为QRCode
    [captureMetadataOutput setMetadataObjectTypes:[NSArray arrayWithObject:AVMetadataObjectTypeQRCode]];
    //6.实例化预览图层
    _videoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:_captureSession];
    //7.设置预览图层填充方式
    [_videoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
    //8.设置图层的frame
    [_videoPreviewLayer setFrame:_viewPreview.layer.bounds];
    //9.将图层添加到预览view的图层上
    [_viewPreview.layer addSublayer:_videoPreviewLayer];
    //10.设置扫描范围
    captureMetadataOutput.rectOfInterest = CGRectMake(0.2f, 0.2f, 0.8f, 0.8f);
    //10.1.扫描框
    _boxView = [[UIView alloc] initWithFrame:CGRectMake(40, (HEIGHT-204)/4, WIDTH-80, (HEIGHT-204)/2)];
    _boxView.layer.borderColor = [UIColor greenColor].CGColor;
    _boxView.layer.borderWidth = 1.0f;
    [_viewPreview addSubview:_boxView];
    //10.2.扫描线
    _scanLayer = [[CALayer alloc] init];
    _scanLayer.frame = CGRectMake(0, 0, _boxView.bounds.size.width, 1);
    _scanLayer.backgroundColor = [UIColor brownColor].CGColor;
    [_boxView.layer addSublayer:_scanLayer];
    NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:0.2f target:self selector:@selector(moveScanLayer:) userInfo:nil repeats:YES];
    [timer fire];

    //10.开始扫描
    [_captureSession startRunning];
    return YES;
}

//实现AVCaptureMetadataOutputObjectsDelegate协议方法

#pragma mark - AVCaptureMetadataOutputObjectsDelegate
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
    //判断是否有数据
    if (metadataObjects != nil && [metadataObjects count] > 0) {
        AVMetadataMachineReadableCodeObject *metadataObj = [metadataObjects objectAtIndex:0];
        //停止扫描
        [self performSelectorOnMainThread:@selector(stopReading) withObject:nil waitUntilDone:NO];
        NSLog(@"账号=%@",[metadataObj stringValue]);
        //扫一扫加好友
        //判断回传的数据类型
        if ([[metadataObj type] isEqualToString:AVMetadataObjectTypeQRCode]) {
            [_lblStatus performSelectorOnMainThread:@selector(setText:) withObject:@"正在添加好友" waitUntilDone:NO];
            _isReading = NO;

            //添加联系人
            dispatch_async(dispatch_get_main_queue(), ^{
                [self addContacts:[metadataObj stringValue]];

            });

        }

    }
}
#pragma mark  添加联系人
-(void)addContacts:(NSString *)account{
        AddContactsViewController *addController=[[AddContactsViewController alloc]init];
        addController.userAccount=account;
        addController.onControllerTitle=@"扫一扫";
        [self.navigationController pushViewController:addController animated:YES];
}

- (void)moveScanLayer:(NSTimer *)timer
{
    CGRect frame = _scanLayer.frame;
    if (_boxView.frame.size.height < _scanLayer.frame.origin.y) {
        frame.origin.y = 0;
        _scanLayer.frame = frame;
    }else{
        frame.origin.y += 5;
        [UIView animateWithDuration:0.1 animations:^{
            _scanLayer.frame = frame;
        }];
    }
}

- (void)startStopReading:(id)sender {
    if (!_isReading) {
        if ([self startReading]) {
            [_startBtn setTitle:@"停止扫描" forState:UIControlStateNormal];
            [_lblStatus setText:@"正在扫描..."];
        }
    }
    else{
        [self stopReading];
        [_startBtn setTitle:@"开始扫描" forState:UIControlStateNormal];
    }
    _isReading = !_isReading;
}

-(void)stopReading{
    [_captureSession stopRunning];
    _captureSession = nil;
    [_scanLayer removeFromSuperlayer];
    [_videoPreviewLayer removeFromSuperlayer];
}


-(void)viewWillAppear:(BOOL)animated{
    [_startBtn setTitle:@"开始扫描" forState:UIControlStateNormal];
    [_lblStatus performSelectorOnMainThread:@selector(setText:) withObject:@"" waitUntilDone:NO];
}


@end