在现有HTML输入字段-UIWebView中加载图像/徽标

由于我是编程新手，我做过如下工作：

- (void)completeUserFieldsForWebView:(UIWebView *)webView withUsername:(NSString *)username {

// TextField Which has Value "email"
NSString *loadUsernameJS =
[NSString stringWithFormat:@"var inputFields = document.querySelectorAll(\"input[type='email']\"); \
 for (var i = inputFields.length >>> 0; i--;) { inputFields[i].value = '%@';}", username];

// TextField Which has Value "Text" if email is not found
NSString *loadText =
[NSString stringWithFormat:@"var inputFields = document.querySelectorAll(\"input[type='text']\"); \
 for (var i = inputFields.length >>> 0; i--;) { inputFields[i].value = '%@';}", username];
[webView stringByEvaluatingJavaScriptFromString: loadUsernameJS];
[webView stringByEvaluatingJavaScriptFromString: loadText];
}

根据我的输入填充所有文本字段

- (void)completePasswordFieldsForWebView:(UIWebView *)webView withPassword:(NSString *)password {

NSString *loadPasswordJS =
[NSString stringWithFormat:@"var passFields = document.querySelectorAll(\"input[type='password']\"); \
 for (var i = passFields.length>>> 0; i--;) { passFields[i].value ='%@';}", password];
[webView stringByEvaluatingJavaScriptFromString: loadPasswordJS];
}

这将填充UIWebView中特定HTML页面中的密码参数

问题是如何在特定的文本框中插入自己的图像

试试第一条：

  [webView stringByEvaluatingJavaScriptFromString:@"var script = document.createElement('script');"
         "script.type = 'text/javascript';"
         "script.text = \"function myFunction() { "
         "var field = document.getElementById('txtAdminPwd');"
         "field.style.backgroundImage='url(icon1.png)';"
         "}\";"
         "document.getElementsByTagName('head')[0].appendChild(script);"];

        [webView stringByEvaluatingJavaScriptFromString:@"myFunction();"];

没有成功

试试2号（@arun's）：

• 本地图像在我的项目外部

先生，谢谢你的努力，但它仍然不能解决通用方法

新测试： 我可以通过[inputNode GetAttributeName:@“id”][方法]获取id或类名

现在，如果我做这样的事情呢

 [webView stringByEvaluatingJavaScriptFromString:@"var script = document.createElement('script');"
         "script.type = 'text/javascript';"
         "script.text = \"function myFunction() { "
         "var field = document.getElementById('%@');"
         "field.style.backgroundImage = 'url('icon1.png')';"

         "}\";"
         "document.getElementsByTagName('head')[0].appendChild(script);",[inputNode getAttributeNamed:@"id"]];

        [webView stringByEvaluatingJavaScriptFromString:@"myFunction();"];

但这是一个错误我们不能通过一个论点吗？？离开：\

我的实际座右铭是在每个输入标签中显示本地图像（通用）

完成：

 NSString *strJSInjection = [NSString stringWithFormat:@".%@{  background-image:url(https://s29.postimg.org/qqxoigjbr/Arun_Photo.png); background-position: right top; background-repeat: no-repeat; background-size: contain; }",[inputNode getAttributeNamed:@"class"]];

        NSString *cssString = strJSInjection; // 1
         NSString *javascriptString = @"var style = document.createElement('style'); style.innerHTML = '%@'; document.head.appendChild(style)"; // 2
        NSString *javascriptWithCSSString = [NSString stringWithFormat:javascriptString, cssString]; // 3
        [webView stringByEvaluatingJavaScriptFromString:javascriptWithCSSString]; // 4

对于本地图像文件，您可以尝试以下代码段

NSString *url = [[NSBundle mainBundle] pathForResource:@"image" ofType:@"png"];
NSString *cssString =  [NSString stringWithFormat:@".textBox{  background-image:url(%@); background-position: right top; background-repeat: no-repeat; background-size: contain; }",url]; // 1

---

你知道要插入图像的textfield的类名或id吗？是的，我确实可以访问文本字段，我尝试注入javascript，但仍然没有成功。请尝试我的回答如果你在使用objective C之前将正确的路径放在本地图像文件中，你可以通过将代码放在这里来确认你的css和链接是否工作谢谢，我已经完成了，如果可能的话，请告诉我如何显示本地图像。我更新了本地文件的答案，你也可以试试。谢谢，在WKWebView中也可以这样做吗？有什么想法吗？

<input type="text" class="textBox" />

- (void)webViewDidFinishLoad:(UIWebView *)webView {
    NSString *cssString = @".textBox{  background-image:url(https://s29.postimg.org/qqxoigjbr/Arun_Photo.png); background-position: right top; background-repeat: no-repeat; background-size: contain; }"; // 1
    NSString *javascriptString = @"var style = document.createElement('style'); style.innerHTML = '%@'; document.head.appendChild(style)"; // 2
    NSString *javascriptWithCSSString = [NSString stringWithFormat:javascriptString, cssString]; // 3
    [webView stringByEvaluatingJavaScriptFromString:javascriptWithCSSString]; // 4
}

NSString *url = [[NSBundle mainBundle] pathForResource:@"image" ofType:@"png"];
NSString *cssString =  [NSString stringWithFormat:@".textBox{  background-image:url(%@); background-position: right top; background-repeat: no-repeat; background-size: contain; }",url]; // 1