iOS开发网络篇 —— OC加载HTML代码

html代码

图1

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样式一："<p><img src=\"/upload/image/20170609/1496978712941664.jpg\" title=\"1496978712941664.jpg\" alt=\"7.jpg\"/>测试内容信息无错</p>" 样式二：<h1 style=\"font-size: 32px; font-weight: bold; border-bottom: 2px solid rgb(204, 204, 204); padding: 0px 4px 0px 0px; text-align: left; margin: 0px 0px 10px;\">你好 <a href=\"https://baidu.com\" target=\"_self\" title=\"五六千可\"> 了的好莱坞去任何</a><img src=\"http://imgsrc.baidu.com/imgad/pic/item/caef76094b36acaf0accebde76d98d1001e99ce7.jpg\"/></h1><p><br/></p>

图2

一、情景1：加载到UILabel上面（转换成富文本即可）

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//1.将字符串转化为标准HTML字符串   NSString *str1 = [self htmlEntityDecode:htmlString]; //2.将HTML字符串转换为attributeString     NSAttributedString * attributeStr = [self attributedStringWithHTMLString:str1];  //3.使用label加载html字符串并将label添加到view上     self.label.attributedText = attributeStr;     [self.label setFrame:CGRectMake(100,100,200,300)];     [self.view addSubview:self.label]; //------html 转换成字符串 //将 &lt 等类似的字符转化为HTML中的“<”等 - (NSString *)htmlEntityDecode:(NSString *)string {     string = [string stringByReplacingOccurrencesOfString:@""" withString:@"\""];     string = [string stringByReplacingOccurrencesOfString:@"'" withString:@"'"];     string = [string stringByReplacingOccurrencesOfString:@"<" withString:@"<"];     string = [string stringByReplacingOccurrencesOfString:@">" withString:@">"];     string = [string stringByReplacingOccurrencesOfString:@"&" withString:@"&"]; // Do this last so that, e.g. @"<" goes to @"<" not @"<"     return string; } //------ 将html转换成富文本 //将HTML字符串转化为NSAttributedString富文本字符串 - (NSAttributedString *)attributedStringWithHTMLString:(NSString *)htmlString {     NSDictionary *options = @{ NSDocumentTypeDocumentAttribute : NSHTMLTextDocumentType,                                NSCharacterEncodingDocumentAttribute :@(NSUTF8StringEncoding) };     NSData *data = [htmlString dataUsingEncoding:NSUTF8StringEncoding];     return [[NSAttributedString alloc] initWithData:data options:options documentAttributes:nil error:nil]; } //图2 中的样式2 可以会出现显示空白，可以通过去除html标签来处理 //去掉 HTML 字符串中的标签 - (NSString *)filterHTML:(NSString *)html {　　NSScanner * scanner = [NSScanner scannerWithString:html];     NSString * text = nil;     while([scanner isAtEnd]==NO)     {         //找到标签的起始位置         [scanner scanUpToString:@"<" intoString:nil];         //找到标签的结束位置         [scanner scanUpToString:@">" intoString:&text];         //替换字符         html = [html stringByReplacingOccurrencesOfString:[NSString stringWithFormat:@"%@>",text] withString:@""];     }     return html; }

二、情景2：加载到UIWebView上面（替换html中部分的字符）

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//1.将字符串转化为标准HTML字符串，(此处的字符串不是标准的标签的HTML字符串,将字符串转换成标准的HTML字符串，这样才可以进行HTML字符串的加载)  NSString *str1 = [self htmlEntityDecode:htmlString];//调用情景1的方法 //2.UIWebView 加载HTML字符串  UIWebView * webView = [[UIWebView alloc] initWithFrame:CGRectMake(20, 150, self.view.frame.size.width-20, 400)];  [webView loadHTMLString:str1 baseURL:nil];  [self.view addSubview:webView];<br>

三、缓存html用RNCachingURLProtocol库。