实现过程如下：
Step1:需要导入：AVFoundation Framework 包含头文件：
#import <AVFoundation/AVFoundation.h>
Step2:设置捕获会话
设置 AVCaptureSession 和 AVCaptureVideoPreviewLayer 成员
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#import <AVFoundation/AVFoundation.h>
static const char *kScanQRCodeQueueName = "ScanQRCodeQueue";
@interface ViewController () <AVCaptureMetadataOutputObjectsDelegate>
.....
@property (nonatomic) AVCaptureSession *captureSession;
@property (nonatomic) AVCaptureVideoPreviewLayer *videoPreviewLayer;
@property (nonatomic) BOOL lastResult;
@end
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Step3:创建会话，读取输入流
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- (BOOL)startReading
{
// 获取 AVCaptureDevice 实例
NSError * error;
AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
// 初始化输入流
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error];
if (!input) {
NSLog(@"%@", [error localizedDescription]);
return NO;
}
// 创建会话
_captureSession = [[AVCaptureSession alloc] init];
// 添加输入流
[_captureSession addInput:input];
// 初始化输出流
AVCaptureMetadataOutput *captureMetadataOutput = [[AVCaptureMetadataOutput alloc] init];
// 添加输出流
[_captureSession addOutput:captureMetadataOutput];
// 创建dispatch queue.
dispatch_queue_t dispatchQueue;
dispatchQueue = dispatch_queue_create(kScanQRCodeQueueName, NULL);
[captureMetadataOutput setMetadataObjectsDelegate:self queue:dispatchQueue];
// 设置元数据类型 AVMetadataObjectTypeQRCode
[captureMetadataOutput setMetadataObjectTypes:[NSArray arrayWithObject:AVMetadataObjectTypeQRCode]];
// 创建输出对象
_videoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:_captureSession];
[_videoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
[_videoPreviewLayer setFrame:_sanFrameView.layer.bounds];
[_sanFrameView.layer addSublayer:_videoPreviewLayer];
// 开始会话
[_captureSession startRunning];
return YES;
}
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Step4:停止读取
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- (void)stopReading
{
// 停止会话
[_captureSession stopRunning];
_captureSession = nil;
}
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Step5:获取捕获数据
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-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects
fromConnection:(AVCaptureConnection *)connection
{
if (metadataObjects != nil && [metadataObjects count] > 0) {
AVMetadataMachineReadableCodeObject *metadataObj = [metadataObjects objectAtIndex:0];
NSString *result;
if ([[metadataObj type] isEqualToString:AVMetadataObjectTypeQRCode]) {
result = metadataObj.stringValue;
} else {
NSLog(@"不是二维码");
}
[self performSelectorOnMainThread:@selector(reportScanResult:) withObject:result waitUntilDone:NO];
}
}
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Step6:处理结果
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- (void)reportScanResult:(NSString *)result
{
[self stopReading];
if (!_lastResult) {
return;
}
_lastResut = NO;
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"二维码扫描"
message:result
delegate:nil
cancelButtonTitle:@"取消"
otherButtonTitles: nil];
[alert show];
// 以下处理了结果，继续下次扫描
_lastResult = YES;
}
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以上基本就是二维码的获取流程