小编net*_*911的帖子

这是一个工作代码：

const AppRouter = () => (
<BrowserRouter>
  <div>
    <Header />
    <Switch>
      <Route path="/" component={DashboardPage} exact={true} />
      <Route path="/:id" component={ViewerPage} /> // <-- Exclude Header component from this page
      <Route path="/create" component={CreatePage} />
      <Route path="/edit/:id" component={EditPage} />
      <Route path="/help" component={HelpPage} />
      <Route component={NotFoundPage} />
    </Switch>
  </div>
</BrowserRouter>
);

export default AppRouter;

我似乎无法弄清楚如何从 ViewerPage 组件页面中排除 Header 组件。有没有办法做到这一点？

我试图找出如何根据使用javascript在另一个输入字段中输入的内容自动填充输入值.这是我的代码:

<script>
add = document.getElementById('address').value;
city = document.getElementById('city').value;
state = document.getElementById('state').value;
zip = document.getElementById('zip').value;
compAdd = add+" "+city+" "+state+" "+zip;
function showAdd(){
    document.getElementById('shipadd1').value=compAdd;
    document.getElementById('add1').innerHTML=compAdd;
}
</script>

<form action="" onchange="showAdd();">

Home Address: <input id="address" name="address" type="text"  /><br/>
Apt or Suite Number: <input id="suite" name="suite" type="text" /><br/>
City/Town: <input id="city" name="city" type="text" /><br/>
State:<select id="state" name="state" value="">...</select><br/>
Zip:<input id="zip" name="zip" type="text" value=""/><br/>


<p> Select Shipping Address Below: </p>

<input type="checkbox" id="shipping-address-1" name="address1" value=""><span id="shiadd1">(Print auto-populated shipping address here...)</span>

<input type="checkbox" id="shipping-address-2" name="address2" …

我有隐藏输入标签的变量名称和值，我想在单击提交按钮时将其附加到表单中。我该如何编码？

这是我的代码：

<script type="text/javascript">

hname="reference";
hvalue="1";

function insertInput(){
document.write( "<input type='hidden' name='" + hname + " ' value=' " + hvalue + " '/><br/>");
}

</script>


<form id="form1">
    <p><label>Username:</label> <input type="text" name="username" size="10"/></p>
    <p><label>Password:</label> <input type="password" name="password" size="10"/></p>

    <p id="hidden"><!-- Insert Hidden input tag here --></p>

    <button type="submit' onClick="insertInput();">Log In</button>  
</form>

我似乎无法让它工作。

我一直试图让countDown()函数在render()函数中自动运行,但似乎无法搞清楚.这是代码:

import React from 'react';
import ReactDOM from 'react-dom';

class Counter extends React.Component {
  constructor(props) {
    super(props);
    this.countDown = this.countDown.bind(this);
    this.state = {
      count: 5,
      message: ''
    }
  }
  countDown() {
    setInterval(() => {
      if (this.state.count <= 0) {
        clearInterval(this);
        this.setState(() => {
          return {message: "Click here to skip this ad"}
        }) 
      } else {
        this.setState((prevState) => {
          return {count: prevState.count - 1}
        }) 
      }
    }, 1000)
  }  
  render() {
    return (
      <div>
        <h1 onLoad={this.countDown}>
          {this.state.message ? this.state.message : this.state.count} …

如何使用JavaScript在我想要的每个页面的内容部分中插入第二个通用(无添加ID或类)"p"节点/标记之后出现的自定义"div"元素？

例如:

<div id="main-content">
  <p>1st paragraph content.....</p>
  <p>2nd paragraph content.....</p>
  <p>3rd paragraph content.....</p>
</div>

输出:

<div id="main-content">
  <p>1st paragraph content.....</p>
  <p>2nd paragraph content.....</p>
  <div id="custom-div">Content here...</div>
  <p>3rd paragraph content.....</p>
</div>