昨天自定义表情键盘的时候发现写一些东西是必要的，不仅是之后方便本身查找，重要的是再一次梳理的时候会加深印象，并且会把当时不清不楚的东西从新拿出来思考一遍，温故知新吧。做为一个菜鸟，尝试写了个二维码扫面和长按识别。下面有连接：
其中用到的东西包括：git
info.plist 设置Privacy - Camera Usage Description - 是否容许此App使用你的相机？github
AVFoundation库web
AVCaptureDevice 设备session
AVCaptureDeviceInput 输入ide
AVCaptureMetadataOutput 输出svg
AVCaptureSession 连接输入及输出内容ui
AVCaptureVideoPreviewLayer 扫描预览layeratom
AVCaptureMetadataOutputObjectsDelegate 扫面代理方法查看扫描结果spa
CIDetector 长按识别扫描仪
CIQRCodeFeature 获取识别结果代理
代码：
import “ViewController.h”
import AVFoundation/AVFoundation.h
define WIDTH [UIScreen mainScreen].bounds.size.width
define HEIGHT [UIScreen mainScreen].bounds.size.height
`
@interface ViewController ()
@property (nonatomic,strong)AVCaptureSession * session;
@property (nonatomic,strong)UIView * scansoinView;
@property (nonatomic,strong)UIImageView * distinguishView;
@property (nonatomic,strong)UILabel * resultLab;
@end
@implementation ViewController
(void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
[self createUI];
// Do any additional setup after loading the view, typically from a nib.
}
-(void)createUI{
_resultLab = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, WIDTH, 64)];
_resultLab.backgroundColor = [UIColor blackColor];
_resultLab.text = @"扫描结果";//
_resultLab.textAlignment = NSTextAlignmentCenter;
_resultLab.textColor = [UIColor whiteColor];
_resultLab.numberOfLines = 0;
[self.view addSubview:_resultLab];
[self createScansionView];
[self createDistinguishView];
NSArray * array = @[@"扫描二维码",@"长按图片识别二维码"];
for (int i = 0; i<array.count; i++) {
UIButton * button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
button.frame = CGRectMake(30, HEIGHT-100 + i*50, WIDTH-60, 40);
[button setTitle:array[i] forState:UIControlStateNormal];
button.backgroundColor = [UIColor blackColor];
[button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
button.tag = 100+i;
[button addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button];
}
}
pragma mark ——————建立扫描页面
-(void)createScansionView{
NSString *mediaType = AVMediaTypeVideo;
AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:mediaType];
if(authStatus == AVAuthorizationStatusRestricted || authStatus == AVAuthorizationStatusDenied){
UIAlertView *alert =[[UIAlertView alloc]initWithTitle:@"获取权限" message:@"请在iPhone的“设置”-“隐私”-“相机”功能中，找到“XXXX”打开相机访问权限" delegate:nil cancelButtonTitle:@"肯定" otherButtonTitles: nil];
[alert show];
return;
}
_scansoinView = [[UIView alloc]initWithFrame:CGRectMake(0, 64, WIDTH, HEIGHT-184)];
_scansoinView.backgroundColor = [UIColor blackColor];
AVCaptureDevice * captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
AVCaptureDeviceInput * deviceInput = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:nil];
AVCaptureMetadataOutput * output = [[AVCaptureMetadataOutput alloc]init];
[output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
_session = [[AVCaptureSession alloc]init];
[_session setSessionPreset:AVCaptureSessionPresetHigh];
if ([_session canAddInput:deviceInput]) {
[_session addInput:deviceInput];
}
if ([_session canAddOutput:output]) {
[_session addOutput:output];
}
output.metadataObjectTypes = @[AVMetadataObjectTypeQRCode];
AVCaptureVideoPreviewLayer * previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:_session];
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
previewLayer.frame = _scansoinView.layer.bounds;
[_scansoinView.layer insertSublayer:previewLayer atIndex:0];
UILabel * xianLab = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, WIDTH, 1)];
xianLab.backgroundColor = [UIColor redColor];
[_scansoinView addSubview:xianLab];
[UIView animateWithDuration:2.5 delay:0.0 options:UIViewAnimationOptionRepeat animations:^{
xianLab.frame = CGRectMake(0, HEIGHT-184, WIDTH, 1);
} completion:nil];
[self.view addSubview:_scansoinView];
[_session startRunning];
}
pragma mark ——————建立识别页面
-(void)createDistinguishView{
_distinguishView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 64, WIDTH, HEIGHT-184)]; _distinguishView.image = [UIImage imageNamed:@"QRCodePic"]; _distinguishView.userInteractionEnabled = YES; UILongPressGestureRecognizer * longPress = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(distinguishClick:)]; [_distinguishView addGestureRecognizer:longPress]; _distinguishView.hidden = YES; [self.view addSubview:_distinguishView];
}
-(void)distinguishClick:(UILongPressGestureRecognizer *)longPress{
UIImageView * imageV = (UIImageView *)longPress.view;
//1. 初始化扫描仪，设置设别类型和识别质量
CIDetector*detector = [CIDetector detectorOfType:CIDetectorTypeQRCode context:nil options:@{ CIDetectorAccuracy : CIDetectorAccuracyHigh }];
//2. 扫描获取的特征组
NSArray *features = [detector featuresInImage:[CIImage imageWithCGImage:imageV.image.CGImage]];
//3. 获取扫描结果
CIQRCodeFeature *feature = [features objectAtIndex:0];
_resultLab.text = [NSString stringWithFormat:@"长按识别二维码结果:%@",feature.messageString];
NSLog(@"长按识别二维码结果：%@",feature.messageString);
}
-(void)buttonClick:(UIButton *)btn{
if (btn.tag == 100) {//扫描二维码
if (!_scansoinView.isHidden) {
return;
}
_scansoinView.hidden = NO;
_distinguishView.hidden = YES;
[_session startRunning];
}else{//识别二维码
if (!_distinguishView.isHidden) {
return;
}
[_session stopRunning];
_scansoinView.hidden = YES;
_distinguishView.hidden = NO;
}
}
-(void)captureOutput:(AVCaptureOutput )captureOutput didOutputMetadataObjects:(NSArray )metadataObjects fromConnection:(AVCaptureConnection *)connection{
[_session stopRunning]; AVMetadataMachineReadableCodeObject * codeOBJ = metadataObjects[0]; _resultLab.text = [NSString stringWithFormat:@"扫描结果:%@",codeOBJ.stringValue]; NSLog(@"扫描结果：metadataObjects = %@",codeOBJ.stringValue);
}
@end
`