寫在前面:建議將代碼復制到Xcode中方便閱讀
1.第一種方法，在代理中加入js實現該功能
.在webview的代理方法中實現
#pragma mark UIWebViewDelegate 方法
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
// 標題不存在時從網頁獲取
if (!self.title) {
NSString *htmlTitle = @"document.title";
self.title = [_webView stringByEvaluatingJavaScriptFromString:htmlTitle];
}
// add by zcj 實現圖片長按識別功能
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 實現圖片長按識別功能
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 實現圖片長按識別二維碼
- (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)// 宏定義在pct文件中，這里用[[UIDevice currentDevice].systemVersion floatValue] >= 8.0替換
detector = [CIDetector detectorOfType:CIDetectorTypeQRCode
context:nil
options:options];
NSArray *features = [detector featuresInImage:[CIImage imageWithCGImage:image.CGImage]] ;
// 識別圖中二維碼
UIAlertAction *judgeCode = [UIAlertAction actionWithTitle:@"識別圖中二維碼" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
CIQRCodeFeature *feature = [features objectAtIndex:0];
NSString *scannedResult = feature.messageString;
if ([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:scannedResult]]){
// 在這里打開這個網址，注意這個scannedResult是string類型。以下是我自己項目里的網頁控制器
/*
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:@"無法識別的網址" title:@"溫馨提示"];
}
}];
// 保存圖片到手機
UIAlertAction *saveImage = [UIAlertAction actionWithTitle:@"保存到手機" 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.第二種方法，通過添加長按手勢，結合js實現該功能
// 首先，在代理方法中為改webview添加長按手勢
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
// add by zcj 實現圖片長按識別功能
UILongPressGestureRecognizer* longPressed = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressed:)];
longPressed.delegate = self;
[self.webView addGestureRecognizer:longPressed];
// ]end
}
// add by zcj 長按識別圖中二維碼
- (void)longPressed:(UILongPressGestureRecognizer*)recognizer
{
if (recognizer.state != UIGestureRecognizerStateBegan) {
return;
}
CGPoint touchPoint = [recognizer locationInView:self.webView];
// 獲取手勢所在圖片的URL，js中圖片的地址是用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，根據獲得的圖片URL進行相應的操作
- (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]];
// 識別圖中二維碼
UIAlertAction *judgeCode = [UIAlertAction actionWithTitle:@"識別圖中二維碼" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
CIQRCodeFeature *feature = [features objectAtIndex:0];
NSString *scannedResult = feature.messageString;
if ([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:scannedResult]]){
// 這里和第一種方法一樣，根據scannedResult做相應的操作即可。下面是我項目中的瀏覽器控制器打開這個網頁。
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:@"無法識別的網址" title:@"溫馨提示"];
}
}];
// 保存圖片到手機
UIAlertAction *saveImage = [UIAlertAction actionWithTitle:@"保存圖片到手機" 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：顯示圖片保存結果
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError*)error contextInfo:(void*)contextInfo
{
if (error){
[Util Alert:@"保存圖片失敗" title:@"溫馨提示"];
}else {
// 這一句僅僅是提示保存成功
[CJUtil showInBottomWithTitle:@"保存成功" backgroundColor:nil textColor:nil];
}
}
// ]end
