Javascript Reactjs遇到两个具有相同键“NaN”的子项。密钥应该是唯一的
我尝试了不同的方法来消除遇到的两个孩子使用相同的钥匙,Javascript Reactjs遇到两个具有相同键“NaN”的子项。密钥应该是唯一的,javascript,reactjs,react-key-index,Javascript,Reactjs,React Key Index,我尝试了不同的方法来消除遇到的两个孩子使用相同的钥匙,NaN。密钥应该是唯一的,这是部分日志: in DynamicFields (at TableHeader.js) in th (at TableHeader.js) in TableHeader 这基本上就是TableHeader.js组件的这一部分,完整的代码粘贴在此页面的下方: return ( <th key={cleanTitle + - + index} ref={(th) =>
NaN
。密钥应该是唯一的,这是部分日志:
in DynamicFields (at TableHeader.js)
in th (at TableHeader.js)
in TableHeader
这基本上就是TableHeader.js组件的这一部分,完整的代码粘贴在此页面的下方:
return (
<th key={cleanTitle + - + index}
ref={(th) => th = th}
style={{width:width}}
data-col={cleanTitle}
>
<span className="header-cell" key={index*11}>{title} </span>
<DynamicFields key={header.index+title} parentIndex={(index + 3) + title} />
</th>
);
import React from "react";
import DynamicFields from "../DynamicFields";
const TableHeader = (props) => {
let FieldTypes = ["text", "dropdown"];
const renderTableHeader = () => {
headers.sort((a, b) => {
if (a.index > b.index) return 1;
return -1
});
const headerView = headers.map((header, index) => {
let title = header.title;
let cleanTitle = header.accessor;
let width = header.width;
return (
<th key={cleanTitle + - + index}
ref={(th) => th = th}
style={{width:width}}
data-col={cleanTitle}
>
<span className="header-cell" key={index*11}>{title} </span>
<DynamicFields key={header.index+title} parentIndex={(index + 3) + title} />
</th>
);
} );
return headerView;
}
return(
<React.Fragment>
{renderTableHeader()}
</React.Fragment>
)
}
返回(
th=th}
样式={{width:width}
数据列={cleanTitle}
>
{title}
);
我已经通读了关于keys和reactjs的文章,然后继续读,但是错误仍然没有停止
下面是呈现datatable时涉及的3个组件:
MyDatatable.js
import React from "react";
import TableHeader from "./TableHeader";
const MyDatatable = (props) => {
columnHeaders = [
{title: "Id" , accessor: 'id' , index: 0},
{title: "Name" , accessor: 'name', width: "300px", index: 2}
]
rowData = [
{id: 1, name: 'a', age: 29, qualification: 'B.com', rating: 3, profile: 'ps'},
{id: 2, name: 'b', age: 35, qualification: 'B.Sc', rating: 5, profile: 'h'}
]
const [headers, setHeaders] = React.useState(columnHeaders);
const [data, setData] = React.useState(rowData)
const renderContent = () => {
let contentView = data.map((row, rowIdx) => {
let id = row[keyField];
let tds = headers.map((header, index) => {
let content = row[header.accessor];
return (
<td key={index} data-id={id} data-row={rowIdx}>
{content}
</td>
);
});
return (
<tr key={rowIdx}>
{tds}
</tr>
);
//
}); //closes contentView variable
return contentView;
}
const renderTable = () => {
let title = props.title || "DataTable";
let contentView = renderContent();
return (
<table className="data-inner-table table-responsive">
<caption className="data-table-caption">
{title}
</caption>
<thead>
<tr>
<TableHeader headers={headers} />
</tr>
</thead>
<tbody>
{contentView}
</tbody>
</table>
)}
return (
<React.Fragment>
<div className={props.className}>
{renderTable() }
</div>
</React.Fragment>
)
}
从“React”导入React;
从“/TableHeader”导入TableHeader;
常量MyDatatable=(道具)=>{
列标题=[
{title:“Id”,访问器:'Id',索引:0},
{标题:“名称”,访问器:“名称”,宽度:“300px”,索引:2}
]
行数据=[
{id:1,姓名:'a',年龄:29岁,资格:'B.com',评级:3,个人资料:'ps'},
{id:2,姓名:'b',年龄:35岁,学历:'b.Sc',等级:5,档案:'h'}
]
const[headers,setHeaders]=React.useState(columnHeaders);
const[data,setData]=React.useState(rowData)
常量renderContent=()=>{
让contentView=data.map((行,rowIdx)=>{
设id=row[keyField];
设tds=headers.map((header,index)=>{
let content=行[header.accessor];
返回(
{content}
);
});
返回(
{tds}
);
//
});//关闭contentView变量
返回contentView;
}
常量可渲染=()=>{
让title=props.title | |“数据表”;
让contentView=renderContent();
返回(
{title}
{contentView}
)}
返回(
{renderable()}
)
}
TableHeader.js
import React from "react";
import DynamicFields from "../DynamicFields";
const TableHeader = (props) => {
let FieldTypes = ["text", "dropdown"];
const renderTableHeader = () => {
headers.sort((a, b) => {
if (a.index > b.index) return 1;
return -1
});
const headerView = headers.map((header, index) => {
let title = header.title;
let cleanTitle = header.accessor;
let width = header.width;
return (
<th key={cleanTitle + - + index}
ref={(th) => th = th}
style={{width:width}}
data-col={cleanTitle}
>
<span className="header-cell" key={index*11}>{title} </span>
<DynamicFields key={header.index+title} parentIndex={(index + 3) + title} />
</th>
);
} );
return headerView;
}
return(
<React.Fragment>
{renderTableHeader()}
</React.Fragment>
)
}
从“React”导入React;
从“./DynamicFields”导入DynamicFields;
const TableHeader=(道具)=>{
让FieldTypes=[“text”,“dropdown”];
常量renderTableHeader=()=>{
headers.sort((a,b)=>{
如果(a.index>b.index)返回1;
返回-1
});
const headerView=headers.map((header,index)=>{
让title=header.title;
让cleanTitle=header.accessor;
让宽度=页眉宽度;
返回(
th=th}
样式={{width:width}
数据列={cleanTitle}
>
{title}
);
} );
返回headerView;
}
返回(
{renderTableHeader()}
)
}
DynamicFields.js
import React, { useState, useEffect, useRef } from "react"
const DynamicFields = (props) => {
const optionsHash = ['Checkbox', 'Dropdown', 'boolean', 'Single line text'];
const [showDynamicField, setShowDynamicField ] = useState(false);
// const dropdownRef = useRef();
const handleShowDynamicField = (event) => {
setShowDynamicField(!showDynamicField);
};
return (
<React.Fragment>
<i className="bi bi-chevron-compact-down" onClick={handleShowDynamicField}></i>
{showDynamicField &&
optionsHash.map( (val, idx) => {
return(
<li key={val-idx} value={val} className="dropdown-item"> {val} </li>
)
})
}
</React.Fragment>
)
}
import React,{useState,useffect,useRef}来自“React”
常量动态字段=(道具)=>{
常量选项哈希=[“复选框”、“下拉列表”、“布尔值”、“单行文本”];
const[showDynamicField,setShowDynamicField]=使用状态(false);
//const dropdownRef=useRef();
常量handleShowDynamicField=(事件)=>{
设置showDynamicField(!showDynamicField);
};
返回(
{showDynamicField&&
选项哈希.map((val,idx)=>{
返回(
{val}
)
})
}
)
}
-
是减法运算符,这将导致键={val idx}
(字符串-数字=>NaN)出现问题。大概您想使用-作为分隔符,所以您应该将其作为字符串使用:
key={val+'-'+idx}
或key={${val}-${idx}}
在本例中,由于optionsHash
具有所有唯一的字符串,因此只需使用key={val}
即可
之所以
key={cleantTitle+-+index}
有效,是因为它的计算结果是cleantTitle+(+index)
,在字符串中添加一个负数,这是允许的(但容易混淆)。key={val idx}
您正在从字符串中减去一个数字,这是NaNThanks,让我检查一下。@Villa7_7添加它作为答案,所以我可以接受。谢谢,接得好。