iOS UIWebView 二维码识别

来源：互联网发布：nfs windows 外网编辑：程序博客网时间：2024/05/22 13:05
1.第一种方法，在代理中加入js实现该功能.在webview的代理方法中实现
#pragma mark UIWebViewDelegate 方法- (void)webViewDidFinishLoad:(UIWebView *)webView{    // 标题不存在时从网页获取    if (!self.title) {        NSString *htmlTitle = @"document.title";        self.title = [_webView stringByEvaluatingJavaScriptFromString:htmlTitle];    }    //  add by zcj 实现图片长按识别功能    static NSString* const kTouchJavaScriptString=    @"document.ontouchstart=function(event){\    x=event.targetTouches[0].clientX;\    y=event.targetTouches[0].clientY;\    document.location=\"myweb:touch:start:\"+x+\":\"+y;};\    document.ontouchmove=function(event){\    x=event.targetTouches[0].clientX;\    y=event.targetTouches[0].clientY;\    document.location=\"myweb:touch:move:\"+x+\":\"+y;};\    document.ontouchcancel=function(event){\    document.location=\"myweb:touch:cancel\";};\    document.ontouchend=function(event){\    document.location=\"myweb:touch:end\";};";    [webView stringByEvaluatingJavaScriptFromString:kTouchJavaScriptString];//注入js方法    // ]end}
#pragma mark UIWebViewDelegate 方法- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{    if (![request.URL.absoluteString isEqualToString:_url])    {        [_backButton setHidden:NO];    }    // add by zcj 实现图片长按识别功能    NSString *requestString =  request.URL.absoluteString;     NSArray *components = [requestString componentsSeparatedByString:@":"];     if ([components count] > 1 && [(NSString *)[components objectAtIndex:0]     isEqualToString:@"myweb"]) {     if([(NSString *)[components objectAtIndex:1] isEqualToString:@"touch"])     {     //NSLog(@"you are touching!");     if ([(NSString *)[components objectAtIndex:2] isEqualToString:@"start"])     {     _gesState = UIGestureRecognizerStateBegan;     float ptX  =[[components objectAtIndex:3]floatValue];     float ptY =[[components objectAtIndex:4]floatValue];     NSString *js = [NSString stringWithFormat:@"document.elementFromPoint(%f, %f).tagName", ptX, ptY];     NSString * tagName = [self.webView stringByEvaluatingJavaScriptFromString:js];     if ([tagName isEqualToString:@"IMG"]) {     self.imgURL = [NSString stringWithFormat:@"document.elementFromPoint(%f, %f).src", ptX, ptY];     }     if (self.imgURL) {     [self performSelector:@selector(handleLongTouch) withObject:nil afterDelay:1.0];     }     }     else if ([(NSString *)[components objectAtIndex:2] isEqualToString:@"move"])     {     _gesState = UIGestureRecognizerStateChanged;     }     }     else if ([(NSString*)[components objectAtIndex:2]isEqualToString:@"end"]) {     _gesState = UIGestureRecognizerStateEnded;     }     }// ]end    return YES;}
// add by zcj#pragma mark 实现图片长按识别二维码- (void)handleLongTouch {    if (self.imgURL && _gesState == UIGestureRecognizerStateBegan) {        UIAlertController *alertController = [UIAlertController alertControllerWithTitle:nil message:nil preferredStyle:UIAlertControllerStyleActionSheet];        NSString *urlToSave = [self.webView stringByEvaluatingJavaScriptFromString:self.imgURL];        NSData* data = [NSData dataWithContentsOfURL:[NSURL URLWithString:urlToSave]];        UIImage* image = [UIImage imageWithData:data];        NSDictionary *options = [[NSDictionary alloc] initWithObjectsAndKeys:                                 @"CIDetectorAccuracy", @"CIDetectorAccuracyHigh",nil];        CIDetector *detector = nil;        if (IOS8_Later)// 宏定义在pct文件中，这里用[[UIDevice currentDevice].systemVersion floatValue] >= 8.0替换            detector = [CIDetector detectorOfType:CIDetectorTypeQRCode                                          context:nil                                          options:options];        NSArray *features = [detector featuresInImage:[CIImage imageWithCGImage:image.CGImage]] ;        // 识别图中二维码        UIAlertAction *judgeCode = [UIAlertAction actionWithTitle:@"识别图中二维码" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {            CIQRCodeFeature *feature = [features objectAtIndex:0];            NSString *scannedResult = feature.messageString;            if ([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:scannedResult]]){                // 在这里打开这个网址，注意这个scannedResult是string类型。以下是我自己项目里的网页控制器              /*                WebBrowser *webBrowser = [[WebBrowser alloc] initWithNibName:@"WebBrowser" bundle:[Util mainBundle]];                [webBrowser loadWebWithTitle:nil urlAddress:scannedResult];                [self.navigationController pushViewController:webBrowser animated:YES];                [webBrowser release];                */            }else{                [Util Alert:@"无法识别的网址" title:@"温馨提示"];            }        }];        // 保存图片到手机        UIAlertAction *saveImage = [UIAlertAction actionWithTitle:@"保存到手机" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {            UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);        }];        // 取消        UIAlertAction *cancell = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {        }];        if (features.count >= 1) {            [alertController addAction:judgeCode];        }        [alertController addAction:saveImage];        [alertController addAction:cancell];        [self presentViewController:alertController animated:YES completion:nil];    }} // ]end
2.第二种方法，通过添加长按手势，结合js实现该功能
// 首先，在代理方法中为改webview添加长按手势
- (void)webViewDidFinishLoad:(UIWebView *)webView{    // add by zcj 实现图片长按识别功能    UILongPressGestureRecognizer* longPressed = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressed:)];    longPressed.delegate = self;    [self.webView addGestureRecognizer:longPressed];    // ]end}// add by zcj 长按识别图中二维码- (void)longPressed:(UILongPressGestureRecognizer*)recognizer{    if (recognizer.state != UIGestureRecognizerStateBegan) {        return;    }    CGPoint touchPoint = [recognizer locationInView:self.webView];    // 获取手势所在图片的URL，js中图片的地址是用src引用的    NSString *imgURL = [NSString stringWithFormat:@"document.elementFromPoint(%f, %f).src", touchPoint.x, touchPoint.y];    NSString *urlToSave = [self.webView stringByEvaluatingJavaScriptFromString:imgURL];    if (urlToSave.length == 0) {        return;    }    [self showImageOptionsWithUrl:urlToSave];}
// 然后，根据获得的图片URL进行相应的操作
- (void)showImageOptionsWithUrl:(NSString *)imgURL{    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:nil message:nil preferredStyle:UIAlertControllerStyleActionSheet];    NSData* data = [NSData dataWithContentsOfURL:[NSURL URLWithString:imgURL]];    UIImage* image = [UIImage imageWithData:data];    NSDictionary *options = [[NSDictionary alloc] initWithObjectsAndKeys:                             @"CIDetectorAccuracy", @"CIDetectorAccuracyHigh",nil];    CIDetector *detector = nil;    if (IOS8_Later)        detector = [CIDetector detectorOfType:CIDetectorTypeQRCode                                      context:nil                                      options:options];    NSArray *features = [detector featuresInImage:[CIImage imageWithCGImage:image.CGImage]];    // 识别图中二维码    UIAlertAction *judgeCode = [UIAlertAction actionWithTitle:@"识别图中二维码" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {        CIQRCodeFeature *feature = [features objectAtIndex:0];        NSString *scannedResult = feature.messageString;        if ([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:scannedResult]]){            // 这里和第一种方法一样，根据scannedResult做相应的操作即可。下面是我项目中的浏览器控制器打开这个网页。            WebBrowser *webBrowser = [[WebBrowser alloc] initWithNibName:@"WebBrowser" bundle:[Util mainBundle]];            [webBrowser loadWebWithTitle:nil urlAddress:scannedResult];            [self.navigationController pushViewController:webBrowser animated:YES];            [webBrowser release];        }else{            [Util Alert:@"无法识别的网址" title:@"温馨提示"];        }    }];    // 保存图片到手机    UIAlertAction *saveImage = [UIAlertAction actionWithTitle:@"保存图片到手机" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {        UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);    }];    // 取消    UIAlertAction *cancell = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {    }];    if (features.count >= 1) {        [alertController addAction:judgeCode];    }    [alertController addAction:saveImage];    [alertController addAction:cancell];    [self presentViewController:alertController animated:YES completion:nil];}// 功能：显示图片保存结果- (void)image:(UIImage *)image didFinishSavingWithError:(NSError*)error contextInfo:(void*)contextInfo{    if (error){        [Util Alert:@"保存图片失败" title:@"温馨提示"];    }else {      // 这一句仅仅是提示保存成功        [CJUtil showInBottomWithTitle:@"保存成功" backgroundColor:nil textColor:nil];    }}// ]end
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