我遇到一种情况，我正在为React中的表实现自定义下拉过滤器。我为每列设置了下拉值，并且有一个“应用”按钮。
为此，我维护了一个子组件，该组件接收下拉值并将选定的子组件发送回父组件。
发生过滤，但是当我再次打开此下拉列表时，复选框值丢失了。
有人可以告诉我我要去哪里了吗
我被困在这里
沙盒：https://codesandbox.io/s/nervous-elgamal-0zztb
我添加了带有适当注释的沙盒链接。请看一看。我有点新反应。
我们将不胜感激
import * as React from "react";
import { render } from "react-dom";
import ReactTable from "react-table";
import "./styles.css";
import "react-table/react-table.css";
import Child from "./Child";
interface IState {
data: {}[];
columns: {}[];
selectedValues: {};
optionsForColumns: {};
}
interface IProps {}
export default class App extends React.Component<IProps, IState> {
// Here I have hardcoded the values, but data and optionsForColumns comes from the backend and it is set inside componentDidMount
constructor(props: any) {
super(props);
this.state = {
data: [
{ firstName: "Jack", status: "Submitted", age: "14" },
{ firstName: "Simon", status: "Pending", age: "15" }
],
selectedValues: {},
columns: [],
optionsForColumns: {
firstName: [{ Jack: "4" }, { Simon: "5" }],
status: [{ Submitted: "5" }, { Pending: "7" }]
}
};
}
// Get the values for checkboxes that will be sent to child
getValuesFromKey = (key: any) => {
let data: any = this.state.optionsForColumns[key];
let result = data.map((value: any) => {
let keys = Object.keys(value);
return {
field: keys[0],
checked: false
};
});
return result;
};
// Get the consolidated values from child and then pass it for server side filtering
handleFilter = (fieldName: any, selectedValue: any, modifiedObj: any) =>
{
this.setState(
{
selectedValues: {
...this.state.selectedValues,
[fieldName]: selectedValue
}
},
() => this.handleColumnFilter(this.state.selectedValues)
);
};
// Function that will make server call based on the checked values from child
handleColumnFilter = (values: any) => {
// server side code for filtering
// After this checkbox content is lost
};
// Function where I configure the columns array for the table . (Also data and column fiter values will be set here, in this case I have hardcoded inside constructor)
componentDidMount() {
let columns = [
{
Header: () => (
<div>
<div>
<Child
key="firstName"
name="firstName"
options={this.getValuesFromKey("firstName")}
handleFilter={this.handleFilter}
/>
</div>
<span>First Name</span>
</div>
),
accessor: "firstName"
},
{
Header: () => (
<div>
<div>
<Child
key="status"
name="status"
options={this.getValuesFromKey("status")}
handleFilter={this.handleFilter}
/>
</div>
<span>Status</span>
</div>
),
accessor: "status",
},
{
Header: "Age",
accessor: "age"
}
];
this.setState({ columns });
}
//Rendering the data table
render() {
const { data, columns } = this.state;
return (
<div>
<ReactTable
data={data}
columns={columns}
/>
</div>
);
}
}
const rootElement = document.getElementById("root");
render(<App />, rootElement);
import * as React from "react";
import { Button, Checkbox, Icon } from "semantic-ui-react";
interface IProps {
options: any;
name: string;
handleFilter(val1: any, val2: any, val3: void): void;
}
interface IState {
showList: boolean;
selected: [];
checkboxOptions: any;
}
export default class Child extends React.Component<IProps, IState> {
constructor(props: any) {
super(props);
this.state = {
selected: [],
showList: false,
checkboxOptions: this.props.options.map((option: any) => option.checked)
};
}
// Checkbox change handler
handleValueChange = (event: React.FormEvent<HTMLInputElement>, data: any) => {
const i = this.props.options.findIndex(
(item: any) => item.field === data.name
);
const optionsArr = this.state.checkboxOptions.map(
(prevState: any, si: any) => (si === i ? !prevState : prevState)
);
this.setState({ checkboxOptions: optionsArr });
};
//Passing the checked values back to parent
passSelectionToParent = (event: any) => {
event.preventDefault();
const result = this.props.options.map((item: any, i: any) =>
Object.assign({}, item, {
checked: this.state.checkboxOptions[i]
})
);
const selected = result
.filter((res: any) => res.checked)
.map((ele: any) => ele.field);
console.log(selected);
this.props.handleFilter(this.props.name, selected, result);
};
//Show/Hide filter
toggleList = () => {
this.setState(prevState => ({ showList: !prevState.showList }));
};
//Rendering the checkboxes based on the local state, but still it gets lost after filtering happens
render() {
let { showList } = this.state;
let visibleFlag: string;
if (showList === true) visibleFlag = "visible";
else visibleFlag = "";
return (
<div>
<div style={{ position: "absolute" }}>
<div
className={"ui scrolling dropdown column-settings " + visibleFlag}
>
<Icon className="filter" onClick={this.toggleList} />
<div className={"menu transition " + visibleFlag}>
<div className="menu-item-holder">
{this.props.options.map((item: any, i: number) => (
<div className="menu-item" key={i}>
<Checkbox
name={item.field}
onChange={this.handleValueChange}
label={item.field}
checked={this.state.checkboxOptions[i]}
/>
</div>
))}
</div>
<div className="menu-btn-holder">
<Button size="small" onClick={this.passSelectionToParent}>
Apply
</Button>
</div>
</div>
</div>
</div>
</div>
);
}
}
答案 0 :(得分：0)
对不起，我在下面的回答是错误的。
在主要组件中，安装组件后，只需设置一次state.columns。此后再也不会更改。
但是，每次更改state.data时，将使用新数据 AND 并使用原始状态重新渲染主组件，并重新渲染ReactTable组件.columns，其中没有有关所选选项的信息。
我认为您应该在每次更新后重建列对象，并向子组件传递selectedOption之类的支持。
您的子道具取决于您的state.selectedValues和state.data。 您可以在render（）中重建列对象。我正在使用buildColumns方法从渲染中获取细节。
您在您的州不需要columns属性。
...
constructor(props) {
super(props);
this.state = {
data: [
{ firstName: "Jack", status: "Submitted", age: "14" },
{ firstName: "Simon", status: "Pending", age: "15" },
{ firstName: "Pete", status: "Approved", age: "16" },
{ firstName: "Lucas", status: "Rejected", age: "19" }
],
selectedValues: {},
};
}
...
buildColumns = ({ data, selectedValues = {} }) => {
const { firstName, status } = selectedValues
return [
{
Header: () => (
<div>
<div style={{ position: "absolute", marginLeft: "10px" }}>
<Child
key="firstName"
name="firstName"
options={this.getValuesFromKey(data, "firstName")}
selectedOption={firstName}
handleFilter={this.handleFilter}
/>
</div>
<span>First Name</span>
</div>
),
accessor: "firstName",
sortable: false,
show: true,
displayValue: " First Name"
},
{
Header: () => (
<div>
<div style={{ position: "absolute", marginLeft: "10px" }}>
<Child
key="status"
name="status"
options={this.getValuesFromKey(data, "status")}
selectedOption={status}
handleFilter={this.handleFilter}
/>
</div>
<span>Status</span>
</div>
),
accessor: "status",
sortable: false
},
{
Header: "Age",
accessor: "age"
}
];
}
render() {
const { data, selectedValues } = this.state;
const columns = this.buildColumns({ data, selectedValues })
return (
<div>
<ReactTable
data={data}
columns={columns}
defaultPageSize={10}
className="-striped -highlight"
/>
</div>
);
}
您仍然必须使用Child组件内的selectedOption道具来预先选中您的复选框。
旧的（和错误的）答案：
获取过滤数据并设置状态后，现在state.data已更改，它将重新渲染Child组件，该组件将从中派生道具。
这会将子组件的状态重新初始化为其{selected: []}值。
为防止这种情况，您应通过仅将状态保留在主组件中，并通过道具传递所选选项的信息来使子组件成为“受控组件”：https://reactjs.org/docs/forms.html#controlled-components