iOS7之前，开发者进行扫码编程时，一般会借助第三方库。扫描二维码 OC 的开源库有 ZBar和ZXing，iOS7之后，系统的AVMetadataObject类中，为我们提供了解析二维码的接口。经过测试，使用原生API扫描和处理的效率非常高，远远高于第三方库。
二维码扫描
在开始之前最重要的一步是要先导入原生的音视频框架即 AVFoundation.framework 。
以下是笔者封装的二维码扫描视图QRView
QRView.h 头文件
#import <UIKit/UIKit.h>
@class QRView;
@protocol QRViewDelegate <NSObject>
/**
* 代理回调扫描结果
*
* @param view 扫一扫视图
* @param result 扫描结果
*/
- (void)qrView:(QRView*)view ScanResult:(NSString*)result;
@end
@interface QRView : UIView
@property(nonatomic,assign)id<QRViewDelegate> delegate;
@property(nonatomic,assign,readonly)CGRect scanViewFrame;
- (void)startScan;
- (void)stopScan;
@end
QRView.m 实现文件
#import "QRView.h"
#import <AVFoundation/AVFoundation.h>
@interface QRView ()<AVCaptureMetadataOutputObjectsDelegate>
@end
@implementation QRView
{
AVCaptureSession *_session;
UIImageView *_scanView;
UIImageView *_lineView;
}
- (instancetype)initWithFrame:(CGRect)frame{
self = [super initWithFrame:frame];
if (self) {
[self initView];
}
return self;
}
- (void)initView
{
UIImage *scanImage = [UIImage imageNamed:@"scanscanBg"];
CGFloat width = CGRectGetWidth(self.frame);
CGFloat height = CGRectGetHeight(self.frame);
CGFloat scanW = 200;
CGRect scanFrame = CGRectMake(width/2.-100, height/2.-100, scanW, scanW);
_scanViewFrame = scanFrame;
_scanView = [[UIImageView alloc]initWithImage:scanImage];
_scanView.backgroundColor = [UIColor clearColor];
_scanView.frame = scanFrame;
[self addSubview:_scanView];
//获取摄像设备
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
//闪光灯
if ([device hasFlash] && [device hasTorch]) {
[device lockForConfiguration:nil];
[device setFlashMode:AVCaptureFlashModeAuto];
[device setTorchMode:AVCaptureTorchModeAuto];
[device unlockForConfiguration];
}
//创建输入流
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
//创建输出流
AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc]init];
//设置代理 刷新线程
[output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
output.rectOfInterest = [self rectOfInterestByScanViewRect:_scanView.frame];
//初始化连接对象
_session = [[AVCaptureSession alloc]init];
//采集率
_session.sessionPreset = AVCaptureSessionPresetHigh;
if (input) {
[_session addInput:input];
}
if (output) {
[_session addOutput:output];
//设置扫码支持的编码格式
NSMutableArray *array = [[NSMutableArray alloc]initWithCapacity:0];
if ([output.availableMetadataObjectTypes containsObject:AVMetadataObjectTypeQRCode]) {
[array addObject:AVMetadataObjectTypeQRCode];
}
if ([output.availableMetadataObjectTypes containsObject:AVMetadataObjectTypeEAN13Code]) {
[array addObject:AVMetadataObjectTypeEAN13Code];
}
if ([output.availableMetadataObjectTypes containsObject:AVMetadataObjectTypeEAN8Code]) {
[array addObject:AVMetadataObjectTypeEAN8Code];
}
if ([output.availableMetadataObjectTypes containsObject:AVMetadataObjectTypeCode128Code]) {
[array addObject:AVMetadataObjectTypeCode128Code];
}
output.metadataObjectTypes = array;
}
AVCaptureVideoPreviewLayer *layer = [AVCaptureVideoPreviewLayer layerWithSession:_session];
layer.videoGravity = AVLayerVideoGravityResizeAspectFill;
layer.frame = self.bounds;
[self.layer insertSublayer:layer above:0];
[self bringSubviewToFront:_scanView];
[self setOverView];
[_session startRunning];
[self loopDrawLine];
}
//设置扫描区域
- (CGRect)rectOfInterestByScanViewRect:(CGRect)rect{
CGFloat width = CGRectGetWidth(self.frame);
CGFloat height = CGRectGetHeight(self.frame);
CGFloat x = (height - CGRectGetHeight(rect))/2/height;
CGFloat y = (width - CGRectGetWidth(rect))/2/width;
CGFloat w = CGRectGetHeight(rect)/height;
CGFloat h = CGRectGetWidth(rect)/width;
return CGRectMake(x, y, w, h);
}
#pragma mark - 添加模糊效果
- (void)setOverView
{
CGFloat width = CGRectGetWidth(self.frame);
CGFloat height = CGRectGetHeight(self.frame);
CGFloat x = CGRectGetMinX(_scanView.frame);
CGFloat y = CGRectGetMinY(_scanView.frame);
CGFloat w = CGRectGetWidth(_scanView.frame);
CGFloat h = CGRectGetHeight(_scanView.frame);
[self creatView:CGRectMake(0, 0, width, y)];
[self creatView:CGRectMake(0, y + h, width, height - y)];
[self creatView:CGRectMake(0, y, x, h)];
[self creatView:CGRectMake(x + w, y, x, h)];
}
- (void)creatView:(CGRect)rect{
CGFloat alpha = 0.5;
UIView *view = [[UIView alloc]initWithFrame:rect];
view.backgroundColor = [UIColor grayColor];
view.alpha = alpha;
[self addSubview:view];
}
#pragma mark - 动画
- (void)loopDrawLine {
UIImage *lineImage = [UIImage imageNamed:@"scanLine"];
CGFloat x = CGRectGetMinX(_scanView.frame);
CGFloat y = CGRectGetMinY(_scanView.frame);
CGFloat w = CGRectGetWidth(_scanView.frame);
CGFloat h = CGRectGetHeight(_scanView.frame);
CGRect start = CGRectMake(x, y, w, 2);
CGRect end = CGRectMake(x, y + h - 2, w, 2);
if (!_lineView) {
_lineView = [[UIImageView alloc]initWithImage:lineImage];
_lineView.frame = start;
[self addSubview:_lineView];
}else{
_lineView.frame = start;
}
__weak typeof(self) weakSelf = self;
[UIView animateWithDuration:2 animations:^{
_lineView.frame = end;
} completion:^(BOOL finished) {
[weakSelf loopDrawLine];
}];
}
#pragma mark - AVCaptureMetadataOutputObjectsDelegate
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
if (metadataObjects.count>0) {
AVMetadataMachineReadableCodeObject *metadataObject = [metadataObjects firstObject];
if ([_delegate respondsToSelector:@selector(qrView:ScanResult:)]) {
[_delegate qrView:self ScanResult:metadataObject.stringValue];
}
}
}
- (void)startScan{
_lineView.hidden = NO;
[_session startRunning];
}
- (void)stopScan{
_lineView.hidden = YES;
[_session stopRunning];
}
@end
调用示例:
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
QRView *qrView = [[QRView alloc]initWithFrame:self.view.bounds];
qrView.delegate = self;
[self.view addSubview:qrView];
}
//代理回调扫描结果
- (void)qrView:(QRView *)view ScanResult:(NSString *)result
{
[view stopScan];
NSLog(@"扫描结果:%@",result);
}
扫一扫示例图片
生成二维码
生成二维码UIImage+QRCode
UIImage+QRCode.h 文件
#import <UIKit/UIKit.h>
@interface UIImage (QRCode)
+ (UIImage *)qrImageByContent:(NSString *)content;
//pre
+ (UIImage *)qrImageWithContent:(NSString *)content size:(CGFloat)size;
/**
* 色值 0~255
*/
+ (UIImage *)qrImageWithContent:(NSString *)content size:(CGFloat)size red:(NSInteger)red green:(NSInteger)green blue:(NSInteger)blue;
+ (UIImage *)qrImageWithContent:(NSString *)content logo:(UIImage *)logo size:(CGFloat)size red:(NSInteger)red green:(NSInteger)green blue:(NSInteger)blue;
@end
UIImage+QRCode.m 文件
#import "UIImage+QRCode.h"
#import <AVFoundation/AVFoundation.h>
@implementation UIImage (QRCode)
void ProviderReleaseData (void *info, const void *data, size_t size){
free((void*)data);
}
+ (CIImage *)qrByContent:(NSString *)content {
CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
NSData *stringData = [content dataUsingEncoding:NSUTF8StringEncoding];
[qrFilter setValue:stringData forKey:@"inputMessage"];
[qrFilter setValue:@"H" forKey:@"inputCorrectionLevel"];
CIImage *image = qrFilter.outputImage;
return image;
}
+ (UIImage *)qrImageWithContent:(NSString *)content size:(CGFloat)size {
CIImage *image = [UIImage qrByContent:content];
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);
CGContextRelease(bitmapRef);
CGImageRelease(bitmapImage);
return [UIImage imageWithCGImage:scaledImage];
}
+ (UIImage *)qrImageWithContent:(NSString *)content size:(CGFloat)size red:(NSInteger)red green:(NSInteger)green blue:(NSInteger)blue {
UIImage *image = [UIImage qrImageWithContent:content size:size];
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);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(rgbImageBuf, imageWidth, imageHeight, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast);
CGContextDrawImage(context, CGRectMake(0, 0, imageWidth, imageHeight), image.CGImage);
// 遍历像素
int pixelNum = imageWidth * imageHeight;
uint32_t* pCurPtr = rgbImageBuf;
for (int i = 0; i < pixelNum; i++, pCurPtr++){
if ((*pCurPtr & 0xFFFFFF00) < 0x99999900) // 将白色变成透明
{
// 改成下面的代码，会将图片转成想要的颜色
uint8_t* ptr = (uint8_t*)pCurPtr;
ptr[3] = red; //0~255
ptr[2] = green;
ptr[1] = blue;
}
else
{
uint8_t* ptr = (uint8_t*)pCurPtr;
ptr[0] = 0;
}
}
// 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];
// 清理空间
CGImageRelease(imageRef);
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
return resultUIImage;
}
+ (UIImage *)qrImageWithContent:(NSString *)content logo:(UIImage *)logo size:(CGFloat)size red:(NSInteger)red green:(NSInteger)green blue:(NSInteger)blue {
UIImage* resultUIImage = [self qrImageWithContent:content size:size red:red green:green blue:blue];
// 添加logo
CGFloat logoW = resultUIImage.size.width / 5.;
CGRect logoFrame = CGRectMake(logoW * 2, logoW * 2, logoW, logoW);
UIGraphicsBeginImageContext(resultUIImage.size);
[resultUIImage drawInRect:CGRectMake(0, 0, resultUIImage.size.width, resultUIImage.size.height)];
[logo drawInRect:logoFrame];
UIImage *kk = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return kk;
}
+ (UIImage *)qrImageByContent:(NSString *)content {
NSData *stringData = [content dataUsingEncoding:NSUTF8StringEncoding];
CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
[qrFilter setValue:stringData forKey:@"inputMessage"];
[qrFilter setValue:@"M" forKey:@"inputCorrectionLevel"];
CIImage *qrImage = qrFilter.outputImage;
CGSize size = CGSizeMake(300, 300);
CGImageRef cgImage = [[CIContext contextWithOptions:nil] createCGImage:qrImage fromRect:qrImage.extent];
UIGraphicsBeginImageContext(size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetInterpolationQuality(context, kCGInterpolationNone);
CGContextScaleCTM(context, 1, -1);
CGContextDrawImage(context, CGContextGetClipBoundingBox(context), cgImage);
UIImage *codeImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGImageRelease(cgImage);
return codeImage;
}
@end
调用示例:
UIImageView *imgView = [[UIImageView alloc] initWithFrame:CGRectZero];
imgView.frame = CGRectMake(0, 0, 200, 200);
imgView.center = self.view.center;
imgView.layer.shadowColor = [UIColor blackColor].CGColor;
imgView.layer.shadowOffset = CGSizeMake(1, 2);
imgView.layer.shadowRadius = 1;
imgView.layer.shadowOpacity = 0.5;
[self.view addSubview:imgView];
imgView.image = [UIImage qrImageByContent:@"www.baidu.com"];
生成的二维码示例
项目地址:https://github.com/524429264/QRCodeDemo
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