Implementation of the QR code function under ios7

After Apple upgraded to IOS7, its PassBook comes with the QR code scanning function. Therefore, the QR code function does not need to be used in third-party libraries.

Before use, please first import AVFoundation. frameWork

// YHQViewController. m

// ReadQRCode

//

// Created by apple on 13-12-22.

// Copyright (c) 2013 apple. All rights reserved.

//

 

# Import "YHQViewController. h"

# Import <AVFoundation/AVFoundation. h>

 

@ InterfaceYHQViewController () <AVCaptureMetadataOutputObjectsDelegate>

 

// IBOutletUILabel * captureLabe is a line in the storyBoard you have created to display the information of the obtained QR code.

 

@ End

 

@ Implementation YHQViewController

 

-(Void) viewDidLoad

{

[SuperviewDidLoad];

# Pragma mark-read the QR code

-(Void) readQRcode

{

// 1. Camera Device

AVCaptureDevice * device = [avcapturedevicedefadevicdevicewithmediatype: AVMediaTypeVideo];

// 2. Set Input

// Because the simulator does not have a camera, it is best to make a judgment here

NSError * error = nil;

AVCaptureDeviceInput * input = [AVCaptureDeviceInputdeviceInputWithDevice: device error: & error];

NSLog (@ "no camera-% @", error. localizedDescription );

}

// 3. Set the output (Metadata)

AVCaptureMetadataOutput * output = [[AVCaptureMetadataOutputalloc] init];

// 3.1 set the output proxy

// Note: the main thread queue is used for synchronization. Other queues are used for synchronization, which may lead to poor user experience.

[Output setMetadataObjectsDelegate: selfqueue: dispatch_get_main_queue ()];

// [Output setMetadataObjectsDelegate: self queue: dispatch_get_global_queue (DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)];

// 4. Shooting sessions

AVCaptureSession * session = [[AVCaptureSessionalloc] init];

// Add session Input and Output

[Session addInput: input];

[Session addOutput: output];

// 4.1 set the output format

// Prompt: You must set the output of the session to output first, and then specify the output metadata type!

[Output setMetadataObjectTypes: @ [AVMetadataObjectTypeQRCode];

// 5. Set the preview layer (used to enable users to see the scan status)

AVCaptureVideoPreviewLayer * preview = [AVCaptureVideoPreviewLayerlayerWithSession: session];

// 5.1 set properties of the preview Layer

[Preview setVideoGravity: AVLayerVideoGravityResizeAspectFill];

// 5.2 set the preview layer size

[Preview setFrame: self. view. bounds];

// 5.3 add a layer to the view

[Self. view. layerinsertSublayer: preview atIndex: 0];

Self. previewLayer = preview;

// 6. Start the session

[Session startRunning];

Self. session = session;

}

 

# Pragma mark-output proxy method

// This method is used to identify the QRCode and complete the conversion.

// If the content of QRCode is greater, the conversion takes longer.

-(Void) captureOutput :( AVCaptureOutput *) captureOutput didOutputMetadataObjects :( NSArray *) metadataObjects fromConnection :( AVCaptureConnection *) connection

{

// Scan frequently and call the proxy method

// 1. If the scan is complete, stop the session

[Self. sessionstopRunning];

// 2. Delete the preview Layer

[Self. previewLayerremoveFromSuperlayer];

NSLog (@ "% @", metadataObjects );

// 3. Set the scan result to be displayed on the page

If (metadataObjects. count> 0 ){

AVMetadataMachineReadableCodeObject * obj = metadataObjects [0];

// Prompt: If you need to scan url or business card information, you can expand it here!

_ CaptureLabel. text = obj. stringValue;

}

}

// Click the link event of the button added in the storyBoard. When you click the button, the system prompts the user to open the camera and scan.

-(IBAction) capture {

// Scan the QR code

[SelfreadQRcode];

}

 

@ End