- 今天项目需要做一个二维码扫描，虽然有很多二维码扫描的第三方可以用，但是考虑到项目中的需要，所以我放弃了使用三方库，而采用了苹果原生的扫描。
- 原生的二维码扫描有一个坑，那就是扫描范围的确定。只要记得扫描范围是X与Y互换位置，W与H互换位置，就没有什么问题了。
- 下面进入正题：
1.因为使用原生二维码扫描，所以需要加入头文件添加delegate
#import <AVFoundation/AVFoundation.h>
<AVCaptureMetadataOutputObjectsDelegate>
2.接着是使用到的类
@property (strong,nonatomic)AVCaptureDevice * device;
@property (strong,nonatomic)AVCaptureDeviceInput * input;
@property (strong,nonatomic)AVCaptureMetadataOutput * output;
@property (strong,nonatomic)AVCaptureSession * session;
@property (weak, nonatomic) IBOutlet UIView *outputView;//xib中扫描的View
@property (strong,nonatomic)AVCaptureVideoPreviewLayer * preview;
@property (strong, nonatomic) NSTimer * timer;//为了做扫描动画的定时器
@property (strong, nonatomic) UIImageView * lineImage;//扫描动画的横线
3.懒加载一个扫描动画的图片
-(UIImageView *)lineImage{
if (!_lineImage) {
CGFloat outputW = self.outputView.frame.size.width;
_lineImage = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0,outputW, 2)];
_lineImage.image = [UIImage imageNamed:@"ray"];
}
return _lineImage;
}
4.使用前的设置，我将它设置在了viewDidLoad当中
-viewDidLoad{
[super viewDidLoad];
// 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];
//连接输入和输出
if ([_session canAddInput:self.input])
{
[_session addInput:self.input];
}
if ([_session canAddOutput:self.output])
{
[_session addOutput:self.output];
}
//设置条码类型
_output.metadataObjectTypes =@[AVMetadataObjectTypeQRCode];
//设置条码位置
CGFloat X = (ScreenW/2-100)/ScreenW;
CGFloat Y = (ScreenH/2-100)/ScreenH;
CGFloat W = 200/ScreenW;
CGFloat H = 200/ScreenH;
//设置扫描范围（注意，X与Y交互，W与H交换）
[_output setRectOfInterest:CGRectMake(Y, X, H, W)];
//添加扫描画面
_preview =[AVCaptureVideoPreviewLayer layerWithSession:_session];
_preview.videoGravity =AVLayerVideoGravityResizeAspectFill;
_preview.frame = CGRectMake(0, 0, ScreenW, ScreenH);//self.view.layer.bounds;
[self.view.layer insertSublayer:_preview atIndex:0];
//开始扫描
[_session startRunning];
//添加扫描动画定时器
[self.outputView addSubview:self.lineImage];
// Do any additional setup after loading the view from its nib.
_timer = [NSTimer scheduledTimerWithTimeInterval:2.5f
target:self
selector:@selector(lineAction)
userInfo:nil
repeats:YES];
}
5.二维码扫描的代理事件
-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
NSString *stringValue;
if ([metadataObjects count] >0){
//停止扫描
[_session stopRunning];
AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects objectAtIndex:0];
stringValue = metadataObject.stringValue;//stringValue是扫描拿到的内容，更具内容进行后续工作。
}
}
6.添加扫描动画的事件
- (void)lineAction{
CGFloat outputW = self.outputView.frame.size.width;
CGFloat outputH = self.outputView.frame.size.height;
[UIView animateWithDuration:2.4f animations:^{
CGRect frame = CGRectMake(0, outputH, outputW, 2);
self.lineImage.frame = frame;
} completion:^(BOOL finished) {
CGRect frame = CGRectMake(0, 0, outputW, 2);
self.lineImage.frame = frame;
}];
}
7.该变扫描视屏方向
_preview.connection.videoOrientation = [self videoOrientationFromCurrentDeviceOrientation];
-(AVCaptureVideoOrientation) videoOrientationFromCurrentDeviceOrientation {
switch (self.interfaceOrientation) {
case UIInterfaceOrientationPortrait: {
return AVCaptureVideoOrientationPortrait;
}
case UIInterfaceOrientationLandscapeLeft: {
return AVCaptureVideoOrientationLandscapeLeft;
}
case UIInterfaceOrientationLandscapeRight: {
return AVCaptureVideoOrientationLandscapeRight;
}
case UIInterfaceOrientationPortraitUpsideDown: {
return AVCaptureVideoOrientationPortraitUpsideDown;
}
default:return AVCaptureVideoOrientationPortrait;
}
}
- 搞定......
- 最后放上一张效果图
原生的扫描就是快，😄
