有關(guān)二維碼的介紹渔期，我這里不做過多說明， 可以直接去基維百科查看尘颓，附上鏈接QR code.
IOS7之前，開發(fā)者進(jìn)行掃碼編程時晦譬，一般會借助第三方庫疤苹。常用的是ZBarSDKa和ZXingObjC，IOS7之后敛腌，系統(tǒng)的AVMetadataObject類中卧土，為我們提供了解析二維碼的接口惫皱。經(jīng)過測試，使用原生API掃描和處理的效率非常高尤莺，遠(yuǎn)遠(yuǎn)高于第三方庫旅敷。
官方提供的接口非常簡單，直接看代碼颤霎，主要使用的是AVFoundation媳谁。
@interfaceViewController()//用于處理采集信息的代理
{
AVCaptureSession* session;//輸入輸出的中間橋梁
}
@end
@implementationViewController
- (void)viewDidLoad {
[superviewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
//獲取攝像設(shè)備
AVCaptureDevice* device = [AVCaptureDevicedefaultDeviceWithMediaType:AVMediaTypeVideo];
//創(chuàng)建輸入流
AVCaptureDeviceInput* input = [AVCaptureDeviceInputdeviceInputWithDevice:device error:nil];
if(!input)return;
//創(chuàng)建輸出流
AVCaptureMetadataOutput* output = [[AVCaptureMetadataOutputalloc]init];
//設(shè)置代理 在主線程里刷新
[output setMetadataObjectsDelegate:selfqueue:dispatch_get_main_queue()];
//設(shè)置有效掃描區(qū)域
CGRectscanCrop=[selfgetScanCrop:_scanWindow.bounds readerViewBounds:self.view.frame];
output.rectOfInterest = scanCrop;
//初始化鏈接對象
_session = [[AVCaptureSessionalloc]init];
//高質(zhì)量采集率
[_session setSessionPreset:AVCaptureSessionPresetHigh];
[_session addInput:input];
[_session addOutput:output];
//設(shè)置掃碼支持的編碼格式(如下設(shè)置條形碼和二維碼兼容)
output.metadataObjectTypes=@[AVMetadataObjectTypeQRCode,AVMetadataObjectTypeEAN13Code,AVMetadataObjectTypeEAN8Code,AVMetadataObjectTypeCode128Code];
AVCaptureVideoPreviewLayer* layer = [AVCaptureVideoPreviewLayerlayerWithSession:_session];
layer.videoGravity=AVLayerVideoGravityResizeAspectFill;
layer.frame=self.view.layer.bounds;
[self.view.layer insertSublayer:layer atIndex:0];
//開始捕獲
[_session startRunning];
}
-(void)captureOutput:(AVCaptureOutput*)captureOutput didOutputMetadataObjects:(NSArray*)metadataObjects fromConnection:(AVCaptureConnection*)connection{
if(metadataObjects.count>0) {
//[session stopRunning];
AVMetadataMachineReadableCodeObject* metadataObject = [metadataObjects objectAtIndex :0];
//輸出掃描字符串
NSLog(@"%@",metadataObject.stringValue);
}
}
一些初始化的代碼加上實現(xiàn)代理方法便完成了二維碼掃描的工作，這里我們需要注意的是友酱， 在二維碼掃描的時候晴音， 我們一般都會在屏幕中間放一個方框，用來顯示二維碼掃描的大小區(qū)間缔杉，這里我們在個AVCaptureMetadataOutput類中有一個rectOfInterest屬性锤躁，它的作用就是設(shè)置掃描范圍。
這個CGRect參數(shù)和普通的Rect范圍不太一樣壮吩，它的四個值的范圍都是0-1进苍，表示比例。
rectOfInterest都是按照橫屏來計算的 所以當(dāng)豎屏的情況下 x軸和y軸要交換一下鸭叙。
寬度和高度設(shè)置的情況也是類似觉啊。
我們在上面設(shè)置有效掃描區(qū)域的方法如下
#pragma mark-> 獲取掃描區(qū)域的比例關(guān)系
-(CGRect)getScanCrop:(CGRect)rect readerViewBounds:(CGRect)readerViewBounds
{
CGFloatx,y,width,height;
x = (CGRectGetHeight(readerViewBounds)-CGRectGetHeight(rect))/2/CGRectGetHeight(readerViewBounds);
y = (CGRectGetWidth(readerViewBounds)-CGRectGetWidth(rect))/2/CGRectGetWidth(readerViewBounds);
width =CGRectGetHeight(rect)/CGRectGetHeight(readerViewBounds);
height =CGRectGetWidth(rect)/CGRectGetWidth(readerViewBounds);
returnCGRectMake(x, y, width, height);
}
讀取主要用到CoreImage 不過要強調(diào)的是讀取二維碼的功能只有在iOS8之后才支持，我們需要在相冊中調(diào)用一個二維碼沈贝，將其讀取杠人，代碼如下
#pragma mark-> 我的相冊
-(void)myAlbum{
NSLog(@"我的相冊");
if([UIImagePickerControllerisSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]){
//1.初始化相冊拾取器
UIImagePickerController*controller = [[UIImagePickerControlleralloc] init];
//2.設(shè)置代理
controller.delegate =self;
//3.設(shè)置資源：
/**
UIImagePickerControllerSourceTypePhotoLibrary,相冊
UIImagePickerControllerSourceTypeCamera,相機
UIImagePickerControllerSourceTypeSavedPhotosAlbum,照片庫
*/
controller.sourceType =UIImagePickerControllerSourceTypeSavedPhotosAlbum;
//4.隨便給他一個轉(zhuǎn)場動畫
controller.modalTransitionStyle=UIModalTransitionStyleFlipHorizontal;
[selfpresentViewController:controller animated:YEScompletion:NULL];
}else{
UIAlertView* alert = [[UIAlertViewalloc]initWithTitle:@"提示"message:@"設(shè)備不支持訪問相冊，請在設(shè)置->隱私->照片中進(jìn)行設(shè)置宋下！"delegate:nilcancelButtonTitle:@"確定"otherButtonTitles:nil,nil];
[alert show];
}
}
完成相冊代理嗡善， 我們在代理中添加讀取二維碼方法
#pragma mark-> imagePickerController delegate
- (void)imagePickerController:(UIImagePickerController*)picker didFinishPickingMediaWithInfo:(NSDictionary*)info
{
//1.獲取選擇的圖片
UIImage*image = info[UIImagePickerControllerOriginalImage];
//2.初始化一個監(jiān)測器
CIDetector*detector = [CIDetectordetectorOfType:CIDetectorTypeQRCodecontext:niloptions:@{CIDetectorAccuracy:CIDetectorAccuracyHigh}];
[picker dismissViewControllerAnimated:YEScompletion:^{
//監(jiān)測到的結(jié)果數(shù)組
NSArray*features = [detector featuresInImage:[CIImageimageWithCGImage:image.CGImage]];
if(features.count >=1) {
/**結(jié)果對象 */
CIQRCodeFeature*feature = [features objectAtIndex:0];
NSString*scannedResult = feature.messageString;
UIAlertView* alertView = [[UIAlertViewalloc]initWithTitle:@"掃描結(jié)果"message:scannedResult delegate:nilcancelButtonTitle:@"確定"otherButtonTitles:nil,nil];
[alertView show];
}
else{
UIAlertView* alertView = [[UIAlertViewalloc]initWithTitle:@"提示"message:@"該圖片沒有包含一個二維碼！"delegate:nilcancelButtonTitle:@"確定"otherButtonTitles:nil,nil];
[alertView show];
}
}];
}
因為沒用真機学歧，所以這里沒有給出太多的截圖罩引， 用模擬器讀取自帶圖片，結(jié)果如下
生成
生成二維碼枝笨，其實也是用到CoreImage袁铐，但是步驟繁瑣一些，代碼如下
#pragma mark-> 二維碼生成
-(void)create{
UIImage*image=[UIImageimageNamed:@"6824500_006_thumb.jpg"];
NSString*tempStr;
if(self.textField.text.length==0){
tempStr=@"ddddddddd";
}else{
tempStr=self.textField.text;
}
UIImage*tempImage=[QRCodeGenerator qrImageForString:tempStr imageSize:360Topimg:image withColor:RandomColor];
_outImageView.image=tempImage;
}
+(UIImage*)qrImageForString:(NSString*)string imageSize:(CGFloat)size Topimg:(UIImage*)topimg withColor:(UIColor*)color{
if(![string length]) {
returnnil;
}
QRcode *code = QRcode_encodeString([string UTF8String],0, QR_ECLEVEL_L, QR_MODE_8,1);
if(!code) {
returnnil;
}
// create context
CGColorSpaceRefcolorSpace =CGColorSpaceCreateDeviceRGB();
CGContextRefctx =CGBitmapContextCreate(0, size, size,8, size *4, colorSpace, kCGImageAlphaPremultipliedLast);
CGAffineTransformtranslateTransform =CGAffineTransformMakeTranslation(0, -size);
CGAffineTransformscaleTransform =CGAffineTransformMakeScale(1,-1);
CGContextConcatCTM(ctx,CGAffineTransformConcat(translateTransform, scaleTransform));
// draw QR on this context
[QRCodeGenerator drawQRCode:code context:ctx size:size withPointType:0withPositionType:0withColor:color];
// get image
CGImageRefqrCGImage =CGBitmapContextCreateImage(ctx);
UIImage* qrImage = [UIImageimageWithCGImage:qrCGImage];
if(topimg)
{
UIGraphicsBeginImageContext(qrImage.size);
//Draw image2
[qrImage drawInRect:CGRectMake(0,0, qrImage.size.width, qrImage.size.height)];
//Draw image1
floatr=qrImage.size.width*35/240;
[topimg drawInRect:CGRectMake((qrImage.size.width-r)/2, (qrImage.size.height-r)/2,r, r)];
qrImage=UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
// some releases
CGContextRelease(ctx);
CGImageRelease(qrCGImage);
CGColorSpaceRelease(colorSpace);
QRcode_free(code);
returnqrImage;
}
+ (void)drawQRCode:(QRcode *)code context:(CGContextRef)ctx size:(CGFloat)size withPointType:(QRPointType)pointType withPositionType:(QRPositionType)positionType withColor:(UIColor*)color {
unsignedchar*data =0;
intwidth;
data = code->data;
width = code->width;
floatzoom = (double)size / (code->width +2.0* qr_margin);
CGRectrectDraw =CGRectMake(0,0, zoom, zoom);
// draw
constCGFloat*components;
if(color) {
components =CGColorGetComponents(color.CGColor);
}else{
components =CGColorGetComponents([UIColorblackColor].CGColor);
}
CGContextSetRGBFillColor(ctx, components[0], components[1], components[2],1.0);
NSLog(@"aad :%f? bbd :%f? ccd:%f",components[0],components[1],components[2]);
for(inti =0; i < width; ++i) {
for(intj =0; j < width; ++j) {
if(*data &1) {
rectDraw.origin =CGPointMake((j + qr_margin) * zoom,(i + qr_margin) * zoom);
if(positionType == QRPositionNormal) {
switch(pointType) {
caseQRPointRect:
CGContextAddRect(ctx, rectDraw);
break;
caseQRPointRound:
CGContextAddEllipseInRect(ctx, rectDraw);
break;
default:
break;
}
}elseif(positionType == QRPositionRound) {
switch(pointType) {
caseQRPointRect:
CGContextAddRect(ctx, rectDraw);
break;
caseQRPointRound:
if((i>=0&& i<=6&& j>=0&& j<=6) || (i>=0&& i<=6&& j>=width-7-1&& j<=width-1) || (i>=width-7-1&& i<=width-1&& j>=0&& j<=6)) {
CGContextAddRect(ctx, rectDraw);
}else{
CGContextAddEllipseInRect(ctx, rectDraw);
}
break;
default:
break;
}
}
}
++data;
}
}
CGContextFillPath(ctx);
}
在textField輸入横浑，生成下圖
這個功能有很多的地方在用剔桨， 最讓人熟知的我想便是微信了，其實實現(xiàn)方法還是很簡單的徙融。
#pragma mark-> 長按識別二維碼
-(void)dealLongPress:(UIGestureRecognizer*)gesture{
if(gesture.state==UIGestureRecognizerStateBegan){
_timer.fireDate=[NSDatedistantFuture];
UIImageView*tempImageView=(UIImageView*)gesture.view;
if(tempImageView.image){
//1. 初始化掃描儀洒缀，設(shè)置設(shè)別類型和識別質(zhì)量
CIDetector*detector = [CIDetectordetectorOfType:CIDetectorTypeQRCodecontext:niloptions:@{CIDetectorAccuracy:CIDetectorAccuracyHigh}];
//2. 掃描獲取的特征組
NSArray*features = [detector featuresInImage:[CIImageimageWithCGImage:tempImageView.image.CGImage]];
//3. 獲取掃描結(jié)果
CIQRCodeFeature*feature = [features objectAtIndex:0];
NSString*scannedResult = feature.messageString;
UIAlertView* alertView = [[UIAlertViewalloc]initWithTitle:@"掃描結(jié)果"message:scannedResult delegate:nilcancelButtonTitle:@"確定"otherButtonTitles:nil,nil];
[alertView show];
}else{
UIAlertView* alertView = [[UIAlertViewalloc]initWithTitle:@"掃描結(jié)果"message:@"您還沒有生成二維碼"delegate:nilcancelButtonTitle:@"確定"otherButtonTitles:nil,nil];
[alertView show];
}
}elseif(gesture.state==UIGestureRecognizerStateEnded){
_timer.fireDate=[NSDatedistantPast];
}
}
我們用剛才生成的二維碼進(jìn)行長按識別，效果如下
本文demo下載地址請點這里Demo,
轉(zhuǎn)自mokey1422所寫的仿支付寶二維碼。
系統(tǒng)原生的二維碼掃描掃描識別速度树绩，要比第三方好用得多萨脑，在沒有特殊原因的情況下，比如7.0系統(tǒng)以下葱峡，我希望大家都能用系統(tǒng)原生的方法砚哗。
文章若有問題請給予指正龙助，感謝砰奕。
