一、与webView进行交互,调用web页面中的需要传参的函数时,参数需要带单引号,或者双引号(双引号需要进行转义在转义字符前加\),在传递json字符串时不需要加单引号或双引号。
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-( void )webViewDidFinishLoad:(UIWebView *)webView |
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NSString *sendJsStr=[NSString stringWithFormat:@ "openFile(\"%@\")" ,jsDocPathStr]; |
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[webView stringByEvaluatingJavaScriptFromString:sendJsStr]; |
2、在该代理方法中判断与webView的交互,可通过html里定义的协议实现
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- ( BOOL )webView:(UIWebView*)webView shouldStartLoadWithRequest:(NSURLRequest*)request navigationType:(UIWebViewNavigationType)navigationType |
3、只有在webView加载完毕之后在能够调用对应页面中的js方法。(对应方法如第一条)
4、为webView添加背景图片
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approvalWebView.backgroundColor=[UIColor clearColor]; |
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approvalWebView.opaque=NO; //这句话很重要,webView是否是不透明的,no为透明 |
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//在webView下添加个imageView展示图片就可以了 |
5、获取webView页面内容信息
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NSString *docStr=[webView stringByEvaluatingJavaScriptFromString:@ "document.documentElement.textContent" ]; //获取web页面内容信息,此处获取的是个json字符串 |
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SBJsonParser *parserJson=[[[SBJsonParser alloc]init]autorelease]; |
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NSDictionary *contentDic=[parserJson objectWithString:docStr]; //将json字符串转化为字典 |
6、加载本地文件的方法
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NSString* path = [[NSBundle mainBundle] pathForResource:name ofType:@ "html" inDirectory:@ "mobile" ]; //mobile是根目录,name是文件名称,html是文件类型 |
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[webView loadRequest:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:path]]]; //加载本地文件 |
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NSString *resourcePath = [[NSBundle mainBundle] resourcePath]; |
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NSString *filePath = [resourcePath stringByAppendingPathComponent:@ "mobile.html" ]; |
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NSString *htmlstring=[[NSString alloc] initWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:nil]; |
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[uiwebview loadHTMLString:htmlstring baseURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] bundlePath]]]; |
7、将文件下载到本地址然后再用webView打开
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NSString *resourceDocPath = [[NSString alloc] initWithString:[[[[NSBundle mainBundle] resourcePath] stringByDeletingLastPathComponent] stringByAppendingPathComponent:@ "Documents" ]]; |
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self.filePath = [resourceDocPath stringByAppendingPathComponent:[NSString stringWithFormat:@ "maydoc%@" ,docType]]; |
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NSData *attachmentData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:theUrl]]; |
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[attachmentData writeToFile:filePath atomically:YES]; |
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NSURL *url = [NSURL fileURLWithPath:filePath]; |
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NSURLRequest *requestObj = [NSURLRequest requestWithURL:url]; |
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[attachmentWebView loadRequest:requestObj]; |
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NSFileManager *magngerDoc=[NSFileManager defaultManager]; |
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[magngerDoc removeItemAtPath:filePath error:nil]; |
8、处理webView展示txt文档乱码问题
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if ([theType isEqualToString:@ ".txt" ]) |
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//txt分带编码和不带编码两种,带编码的如UTF-8格式txt,不带编码的如ANSI格式txt |
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//不带的,可以依次尝试GBK和GB18030编码 |
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NSString* aStr = [[NSString alloc] initWithData:attachmentData encoding:NSUTF8StringEncoding]; |
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//用GBK<strong>进行</strong>编码 |
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aStr=[[NSString alloc] initWithData:attachmentData encoding:0x80000632]; |
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//用GBK编码不行,再用GB18030编码 |
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aStr=[[NSString alloc] initWithData:attachmentData encoding:0x80000631]; |
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//通过html语言<strong>进行</strong>排版 |
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NSString* responseStr = [NSString stringWithFormat: |
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"<title>Text View</title>" |
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[attachmentWebView loadHTMLString:responseStr baseURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] bundlePath]]]; |
9 、使用webView加载本地或网络文件整个流程
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1、 Loading a local PDF file into the web view |
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NSString *thePath = [[NSBundle mainBundle] pathForResource:@ "iPhone_User_Guide" ofType:@ "pdf" ]; |
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NSData *pdfData = [NSData dataWithContentsOfFile:thePath]; |
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[(UIWebView *)self.view loadData:pdfData MIMEType:@ "application/pdf" |
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textEncodingName:@ "utf-8" baseURL:nil]; |
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[self.myWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@ "http://www.apple.com/" ]]]; |
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2、The web-view delegate managing network loading |
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- ( void )webViewDidStartLoad:(UIWebView *)webView |
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// starting the load, show the activity indicator in the status bar |
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[UIApplication sharedApplication].networkActivityIndicatorVisible = YES; |
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- ( void )webViewDidFinishLoad:(UIWebView *)webView |
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// finished loading, hide the activity indicator in the status bar |
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[UIApplication sharedApplication].networkActivityIndicatorVisible = NO; |
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- ( void )webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error |
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// load error, hide the activity indicator in the status bar |
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[UIApplication sharedApplication].networkActivityIndicatorVisible = NO; |
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// report the error inside the webview |
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NSString* errorString = [NSString stringWithFormat: |
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@ "<html><center><font size=+5 color='red'>An error occurred:<br>%@</font></center></html>" , |
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error.localizedDescription]; |
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[self.myWebView loadHTMLString:errorString baseURL:nil]; |
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3、Stopping a load request when the web view is to disappear |
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- ( void )viewWillDisappear:( BOOL )animated |
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if ( [self.myWebView loading] ) { |
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[self.myWebView stopLoading]; |
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self.myWebView.delegate = nil; // disconnect the delegate as the webview is hidden |
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[UIApplication sharedApplication].networkActivityIndicatorVisible = NO; |
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引用自苹果官方文档(displaying web content) |
10、查找webView中的scrollview
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- ( void ) addScrollViewListener |
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UIScrollView* currentScrollView; |
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for (UIView* subView in self.webView.subviews) { |
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if ([subView isKindOfClass:[UIScrollView class ]]) { |
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currentScrollView = (UIScrollView*)subView; |
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currentScrollView.delegate = self; |
11、去掉webView的阴影,做成类似scrollView
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- ( void )clearBackgroundWithColor:(UIColor*)color |
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self.backgroundColor = color; |
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for (UIView* subView in [self subviews]) |
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if ([subView isKindOfClass:[UIScrollView class ]]) { |
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for (UIView* shadowView in [subView subviews]) |
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if ([shadowView isKindOfClass:[UIImageView class ]]) { |
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[shadowView setHidden:YES]; |
12、取消长按webView上的链接弹出actionSheet的问题
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-( void )webViewDidFinishLoad:(UIWebView *)webView |
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[webView stringByEvaluatingJavaScriptFromString:@ "document.documentElement.style.webkitTouchCallout = 'none';" ]; |
13、取消webView上的超级链接加载问题
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-( BOOL )webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType |
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if (navigationType==UIWebViewNavigationTypeLinkClicked) { |
14、一、webView在ios5.1之前的bug:在之前的工程中使用webView加载附件,webView支持doc,excel,ppt,pdf等格式,但这些附件必须先下载到本地然后在加载到webView上才可以显示, 当附件下载到本地之后刚刚开始加载到webView上时,此时退出附件页面会导致程序崩溃。会崩溃是由于webView控件内部没有把相关代理取消掉,所以导致退出之后程序崩溃。
二、webView在5.1上的bug:之前项目需求要webView可以左右活动,但在往webView上加载页面时导致页面加载不全,这个bug是由于webView本身的缓存所致。(还有待研究)
15、在使用webView进行新浪微博分享时,webView会自动保存登陆的cookie导致项目中的分享模块有些问题,删除 webView的cookie的方法
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-( void )deleteCookieForDominPathStr:(NSString *)thePath |
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//删除本地cookie,thePath为cookie路径通过打印cookie可知道其路径 |
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for (NSHTTPCookie *cookie in [[NSHTTPCookieStorage sharedHTTPCookieStorage] cookies]) { |
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if ([[cookie domain] isEqualToString:thePath]) { |
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[[NSHTTPCookieStorage sharedHTTPCookieStorage] deleteCookie:cookie]; |
16、在UIWebView中使用flashScrollIndicators
使用UIScrollView时,我们可以使用flashScrollIndicators方法显示滚动标识然后消失,告知用户此页面可以滚动,后面还有更多内容。UIWebView内部依赖于UIScrollView,但是其没有flashScrollIndicators方法,但可以通过其他途径使用此方法,如下所示。
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for (id subView in [webView subviews]) |
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{ if ([subView respondsToSelector:@selector(flashScrollIndicators)]) |
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[subView flashScrollIndicators]; |
上述代码片段可以到webViewDidFinishLoad回调中使用,加载完网页内容后flash显示滚动标识。
17、根据内容获取UIWebView的高度
有时候需要根据不同的内容调整UIWebView的高度,以使UIWebView刚好装下所有内容,不用拖动,后面也不会留白。有两种方式可根据加载内容获取UIWebView的合适高度,但都需要在网页内容加载完成后才可以,即需要在webViewDidFinishLoad回调中使用。
①.使用sizeThatFits方法。
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- ( void )webViewDidFinishLoad:(UIWebView *)webView |
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CGRect frame = webView.frame; |
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CGSize fittingSize = [webView sizeThatFits:CGSizeZero]; |
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frame.size = fittingSize; |
sizeThatFits方法有个问题,如果当前UIView的大小比刚好合适的大小还大,则返回当前的大小,不会返回最合适的大小值,所以使用sizeThatFits前,先将UIWebView的高度设为最小,即1,然后再使用sizeThatFits就会返回刚好合适的大小。
②、使用JavaScript
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- ( void )webViewDidFinishLoad:(UIWebView *)webView |
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{ CGRect frame = webView.frame; |
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NSString *fitHeight = [webview stringByEvaluatingJavaScriptFromString:@ "document.body.scrollHeight;" ]; |
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frame.size.height = [fitHeight floatValue]; |
参考:
Three useful UIWebView tweaks
How to determine UIWebView height based on content, within a variable height UITableView?
How to determine the content size of a UIWebView?
clientHeight,offsetHeight和scrollHeight区别