Javascript 如何在react js中使用变量 从“React”导入React 从“反应路由器”导入{Link} var结果;var反应;var-jsonString;var-msg; var xhr=new XMLHttpRequest(); var xhrPost=newXMLHttpRequest(); 函数xhrGetCall(getUrl){ xhr.onreadystatechange=函数(){ if(xhr.readyState==XMLHttpRequest.DONE){ 结果=xhr.responseText; jsonString=JSON.parse(结果); log('检索到的API数据:'+jsonString); 返回结果; } } open('GET',getUrl,true); setRequestHeader(“访问控制允许原点”,true); setRequestHeader('Content-Type','application/json'); xhr.send(空); xhr.onerror=函数(xhr、textStatus、errorshown){ log('数据加载失败:('+JSON.stringify(xhr)); }; }; 函数xhrPostCall(jsonInput、postrl){ xhrPost.open(“POST”,postrl,true); setRequestHeader(“内容类型”、“应用程序/json”); xhrPost.onreadystatechange=函数(){ if(xhrPost.readyState==XMLHttpRequest.DONE&&xhrPost.status==200){ msg=“成功!”; console.log('posting successful'+jsonInput); } 否则{ msg=“失败!”; 警报('消息为:'+消息); console.log('posting unsuccessful'+消息); } } xhrPost.send(jsonInput); 返回味精; } 类AddDetailsModel扩展了React.Component{ 建造师(道具){ 超级(道具); this.state={用户名:'}; this.handleChangeUserName=this.handleChangeUserName.bind(this); this.handleSubmit=this.handleSubmit.bind(this); this.handleClick=this.handleClick.bind(this); xhrGetCall(this.props.getUrl); xhr.onload=函数(){ response=JSON.parse(xhr.responseText); this.setState({apireutvalue:jsonToHtmlSelect(response)}); }.约束(本); } componentDidMount(){ } handleChangeUserName(事件){ this.setState({UserName:event.target.value}); } handleSubmit(事件){ var str={“UserName”:this.state.UserName}; var json=json.stringify(str); xhrPostCall(json,this.props.postrl); this.setState({msg:xhrPostCall()}); 日志(“测试:msg:+msg”); $('#AddDetailsModal').on('hidden.bs.modal',function(e){ $(本) .find(“输入,文本区域”) .val(“”) (完) .find(“输入[type=checkbox],输入[type=radio]”) .prop(“选中的”,“”) .end(); }) } render(){ 返回( &时代; 添加详细信息 姓名: 取消 提交 &时代; 消息标题 {msg} 取消 ); } } 导出默认AddDetailsModel;
我已经制作了一个react组件“AddDetailsModal”,它是引导表单模式,在handleSubmit()函数成功或失败提交表单时,另一个模式“AddMsgModal”应该显示消息 我无法访问react js的render()中函数xhrPostCall中声明的msg变量Javascript 如何在react js中使用变量 从“React”导入React 从“反应路由器”导入{Link} var结果;var反应;var-jsonString;var-msg; var xhr=new XMLHttpRequest(); var xhrPost=newXMLHttpRequest(); 函数xhrGetCall(getUrl){ xhr.onreadystatechange=函数(){ if(xhr.readyState==XMLHttpRequest.DONE){ 结果=xhr.responseText; jsonString=JSON.parse(结果); log('检索到的API数据:'+jsonString); 返回结果; } } open('GET',getUrl,true); setRequestHeader(“访问控制允许原点”,true); setRequestHeader('Content-Type','application/json'); xhr.send(空); xhr.onerror=函数(xhr、textStatus、errorshown){ log('数据加载失败:('+JSON.stringify(xhr)); }; }; 函数xhrPostCall(jsonInput、postrl){ xhrPost.open(“POST”,postrl,true); setRequestHeader(“内容类型”、“应用程序/json”); xhrPost.onreadystatechange=函数(){ if(xhrPost.readyState==XMLHttpRequest.DONE&&xhrPost.status==200){ msg=“成功!”; console.log('posting successful'+jsonInput); } 否则{ msg=“失败!”; 警报('消息为:'+消息); console.log('posting unsuccessful'+消息); } } xhrPost.send(jsonInput); 返回味精; } 类AddDetailsModel扩展了React.Component{ 建造师(道具){ 超级(道具); this.state={用户名:'}; this.handleChangeUserName=this.handleChangeUserName.bind(this); this.handleSubmit=this.handleSubmit.bind(this); this.handleClick=this.handleClick.bind(this); xhrGetCall(this.props.getUrl); xhr.onload=函数(){ response=JSON.parse(xhr.responseText); this.setState({apireutvalue:jsonToHtmlSelect(response)}); }.约束(本); } componentDidMount(){ } handleChangeUserName(事件){ this.setState({UserName:event.target.value}); } handleSubmit(事件){ var str={“UserName”:this.state.UserName}; var json=json.stringify(str); xhrPostCall(json,this.props.postrl); this.setState({msg:xhrPostCall()}); 日志(“测试:msg:+msg”); $('#AddDetailsModal').on('hidden.bs.modal',function(e){ $(本) .find(“输入,文本区域”) .val(“”) (完) .find(“输入[type=checkbox],输入[type=radio]”) .prop(“选中的”,“”) .end(); }) } render(){ 返回( &时代; 添加详细信息 姓名: 取消 提交 &时代; 消息标题 {msg} 取消 ); } } 导出默认AddDetailsModel;,javascript,reactjs,Javascript,Reactjs,我已经制作了一个react组件“AddDetailsModal”,它是引导表单模式,在handleSubmit()函数成功或失败提交表单时,另一个模式“AddMsgModal”应该显示消息 我无法访问react js的render()中函数xhrPostCall中声明的msg变量 请告诉我如何在那里访问该变量?首先使用类似labriry的工具创建一些ajax请求 Second-如果您想自己创建它,请使用Promise创建异步操作: import React from 'react' import
请告诉我如何在那里访问该变量?首先使用类似labriry的工具创建一些ajax请求 Second-如果您想自己创建它,请使用
Promise
创建异步操作:
import React from 'react'
import { Link } from 'react-router'
var result;var response;var jsonString ;var msg;
var xhr = new XMLHttpRequest();
var xhrPost = new XMLHttpRequest();
function xhrGetCall(getUrl){
xhr.onreadystatechange = function() {
if (xhr.readyState == XMLHttpRequest.DONE) {
result = xhr.responseText;
jsonString = JSON.parse(result);
console.log('API data retrieved:'+jsonString);
return result;
}
}
xhr.open('GET', getUrl, true);
xhr.setRequestHeader("Access-Control-Allow-Origin", true);
xhr.setRequestHeader( 'Content-Type', 'application/json' );
xhr.send(null);
xhr.onerror = function(xhr, textStatus, errorThrown) {
console.log( 'The data failed to load :('+JSON.stringify(xhr));
};
};
function xhrPostCall(jsonInput, postUrl){
xhrPost.open("POST",postUrl, true);
xhrPost.setRequestHeader("Content-type", "application/json");
xhrPost.onreadystatechange = function() {
if(xhrPost.readyState == XMLHttpRequest.DONE && xhrPost.status == 200) {
msg="succesful!";
console.log('posting succesful'+jsonInput);
}
else {
msg="failed!";
alert('msg is:'+msg);
console.log('posting unsuccesful'+msg);
}
}
xhrPost.send(jsonInput);
return msg;
}
class AddDetailsModal extends React.Component {
constructor(props) {
super(props);
this.state = {UserName: ''};
this.handleChangeUserName = this.handleChangeUserName.bind(this);
this.handleSubmit = this.handleSubmit.bind(this);
this.handleClick=this.handleClick.bind(this);
xhrGetCall(this.props.getUrl);
xhr.onload = function() {
response = JSON.parse(xhr.responseText);
this.setState({apiReturnValue:jsonToHtmlSelect(response)});
}.bind(this);
}
componentDidMount(){
}
handleChangeUserName(event) {
this.setState({UserName: event.target.value});
}
handleSubmit(event) {
var str = {"UserName": this.state.UserName};
var json = JSON.stringify(str);
xhrPostCall(json,this.props.postUrl);
this.setState({msg:xhrPostCall()});
console.log("testing: msg:"+msg);
$('#AddDetailsModal').on('hidden.bs.modal', function (e) {
$(this)
.find("input,textarea")
.val('')
.end()
.find("input[type=checkbox], input[type=radio]")
.prop("checked", "")
.end();
})
}
render() {
return (
<div>
<div id="AddDetailsModal" className="modal fade" role="dialog">
<div className="modal-dialog">
<div className="modal-content">
<div className="modal-header">
<button type="button" className="close" data-dismiss="modal">×</button>
<h4 className="modal-title">Add Details</h4>
</div>
<div className="modal-body">
<div className="form-group">
<label className="col-sm-0 control-label" htmlFor="textinput"> Name : </label>
<input type="text" value={this.state.UserName} onChange={this.handleChangeUserName} placeholder="Name" className="form-control"></input>
</div>
<div className="modal-footer">
<button type="submit" className="btn btn-default" data-dismiss="modal">Cancel</button>
<button type="submit" value="submit" onClick={this.handleSubmit} className="btn btn-primary" data-dismiss="modal" data-toggle="modal" href="#AddMsgModal">Submit</button>
</div>
</div>
</div>
</div>
<div id="AddMsgModal" className="modal fade" role="dialog">
<div className="modal-dialog">
<div className="modal-content">
<div className="modal-header">
<button type="button" className="close" data-dismiss="modal">×</button>
<h4 className="modal-title">Message Heading</h4>
</div>
<div className="alert alert-success">
{msg}
</div>
<div className="modal-footer">
<button type="submit" className="btn btn-default" data-dismiss="modal">Cancel</button>
</div>
</div>
</div>
</div>
</div>
);
}
}
export default AddDetailsModal;
然后在组件中:
return new Promise((resolve) => {
//perform some async actions
resolve(result)
})
在声明过程中,您需要在组件的属性中添加msg变量
,然后在组件中,您可以通过this.props.msg
在渲染函数中访问它。您能解释一下吗?AddDetailsModal表单是一个表单,在提交时,我打开AddMsgModal并将此{msg}显示到该模式中。
fetchData().then((result) => this.setState({msg: result})