我想从我的选择中检索值,以便我可以提出发布请求。我从文本输入中获取没有问题,但由于某种原因我无法从下拉菜单选择中获取它。我最终得到一个
"TypeError: Cannot read property 'value' of undefined"
这是我正在使用的代码。
import React from "react";
import { Form, Input, Button, Select } from "antd";
const { Option } = Select;
class ItemForm extends React.Component {
handleFormSubmit = event => {
event.preventDefault();
const name = event.target.elements.name.value;
const description = event.target.elements.description.value;
const category = event.target.elements.category.value;
console.log(name, description, this.refs.category.value);
};
render() {
return (
<div>
<Form onSubmit={this.handleFormSubmit}>
<Form.Item label="Form Layout" />
<Form.Item label="Product Name">
<Input name="name" placeholder="Ex: Organic Apple..." />
</Form.Item>
<Form.Item label="Description">
<Input name="description" …Run Code Online (Sandbox Code Playgroud) 我正在尝试为我的TextInputin react native 添加辅助功能,以便将其读作手机号而不是数字,如下所示.
<TextInput
style={{height: 40, borderColor: 'gray', borderWidth: 1}}
editable={false}
accessibilityLabel={'26726855243'}
value={'26726855243'}
/>
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这是由Android TalkBack和iOS VoiceOver读取的数字.我试过在数字之间添加空格但仍然无效,accessibilityLabel={'26726855243'.split('').join(' ')}
嗨,我有一个代码,用于从richtextbox中查找单词并更改字体颜色,代码正常工作但ifi返回并将之前的文本编辑为我不想着色的内容,颜色不会消失.这是我的代码
Private Sub RichTextBox1_TextChanged(sender As Object, e As EventArgs) Handles RichTextBox1.TextChanged
Dim S As Integer = RichTextBox1.SelectionStart
Dim html() As String = {"<!DOCTYPE html>", "<html>", "</html>", "<head>", "</head>", "<body>", "</body>", "pre>", "</pre>", "<!DOCTYPE>", "<title>", "</title>", "<a>",
"<abbr>", "<address>", "<area>", "<article>", "<aside>", "<audio>", "<acronym>", "<applet>", "<b>", "<base>", "<bdi>", "<bdo>", "<blockquote>", "<body>", "<br>", "<button>", "<basefont>", "<bgsound>", "<big>", "<blink>"}
For i As Integer = 0 To html.Length - 1
Dim str As String = html(i)
Dim start As Integer = S - str.Length …Run Code Online (Sandbox Code Playgroud) 我遇到了问题FormData,它已经在几天前工作了,但是现在不起作用了,它提交了所有的输入,但提交按钮除外。这是我的登录表格。
<form action="" method="post" name="login_user">
<label for="username">Username/e-mail <span class="error" id="user-error"></span></label>
<input type="text" name="username" id="username" required>
<br>
<label for="passwd">Password <span class="error" id="passwd-error"></span></label>
<input type="password" name="passwd" id="passwd" required>
<br>
<p><input type="checkbox" checked name="remember"> Remember me <span class="forgot"><a href="<?php echo SITE_URL; ?>/reset">Forgotten password</a></span> </p>
<input type="submit" id="login" value="Login" name="login">
<p>Don't have an account? <a href="<?php echo SITE_URL; ?>/register/">Sign up</a></p>
</form>
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JS用于登录,使用MVC。
//ajax login
var login = document.forms.namedItem('login_user');
if (login) {
login.addEventListener('submit', function (e) {
if (validatePassword('passwd', 'passwd-error')) {
var data = …Run Code Online (Sandbox Code Playgroud) 我写了一个简单的生成器来创建商品。效果很好,但是我遇到了打印问题。当我尝试从AJAX请求打印页面时,我得到的索引页面不是来自AJAX请求的数据。
怎么了?
此外,来自AJAX的数据是正确的。
$.post({
type: "POST",
url: "generate.php",
data: {pid: pid, net: net, brutto: brutto, contractor: contractor, delivery: delivery, term: term},
}).done(function(data) {
window.print(data);
});
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PHP文件示例:
<?php
$foo = "foo";
ob_start();
?>
<p><?php echo $foo; ?></p>
<?php
$result = ob_get_flush();
echo $result;
?>
Run Code Online (Sandbox Code Playgroud) 我试图在单击“x”按钮时让警报消失,但似乎缺少某些东西使其无法工作,不确定它是什么。
<div class="alert alert-success alert-dismissible">
<button type = "button" class="close" data-dismiss = "alert">x</button>
You've done it!
</div>
Run Code Online (Sandbox Code Playgroud) 我想按类别在gridview中对电影分组。我有C#代码,我想将其转换为Visual Basic。
var moviesByCategories = movies.GroupBy(x => x.Category)
.Select(x => new MovieCategory { Title = x.Key, Items = x.ToList() });
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我尝试了以下代码,但它给了我一个错误。
Dim query = From film In movies Group film.Title By Category = film.Category Into grpTitle = Group
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UPDATE使用Plutonix建议的converter.telerik.com
Dim moviesByCategories = movies.GroupBy(Function(x) x.Category).[Select](Function(x) New MovieCategory() With { _
Key .Title = x.Key, _
Key .Items = x.ToList() _
})
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但是代码不起作用给出了以下错误

我的课程1. MoviePageViewModel
Public Class MoviesPageViewModel
Private _Items As List(Of MovieCategory)
Public Property Items() As List(Of MovieCategory)
Get
Return _Items …Run Code Online (Sandbox Code Playgroud) 我有一个像这样的数组:
"pages": [{
"key": "1",
"pages": [{
"key": "2",
"pages": [{
"key": "3"
}]
},
{
"key": "4",
"pages": [{
"key": "5"
}]
}]
}]
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其中键1和4处于同一级别,1包含2,其中包含3,键4包含5.我想要的结果是顺序[3,2,5,1,4].我尝试了以下递归,但我无法得到正确的顺序.
function fnGetAll (oTopDetailPage, array) {
var i;
for (i=0; i<oTopDetailPage.length; i++) {
array.push(oTopDetailPage[i]);
if(oTopDetailPage[i].pages) {
fnGetAllSubPages(oTopDetailPage[i].pages, array);
}
}
return array;
}
Run Code Online (Sandbox Code Playgroud) 该功能只是我需要实现的逻辑的一小部分,代码变得越来越长,我正在寻找创造性的方式以短格式编写此任务。
if (type === '30d') {
self.setState({
startDate: last30d,
endDate: now
},
() => {
this.fetchPeriod('income');
this.fetchPeriod('expense');
this.fetchSettings();
}
);
} else if (type === '15d') {
self.setState({
startDate: last15d,
endDate: now
},
() => {
this.fetchPeriod('income');
this.fetchPeriod('expense');
this.fetchSettings();
}
);
} else if (type === '7d') {
self.setState({
startDate: last7d,
endDate: now
},
() => {
this.fetchPeriod('income');
this.fetchPeriod('expense');
this.fetchSettings();
}
);
}
Run Code Online (Sandbox Code Playgroud) 我想在用 expo cli 构建的 ReactNative 应用程序中生成一个 uuid .. 当我UUIDGenerator从安装时React-native-uuid-generator,我得到undefined is not an object(evaluating ‘RNUUIDGenerator.getRandomUUID’..)
尝试了两个差异库,react-native-uuid和React-native-uuid-generator,同样的问题,认为这可能与 expo 不喜欢链接命令有关。
UUIDGenerator.getRandomUUID().then(uuid => console.log(uuid));
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期望打印新的 uuid,实际上收到错误消息。