Reactjs 物料Ui日期选择器出现错误：应为字符串

我正在尝试使用材质UI的日期选择器在React项目中实现日期选择器。我最初试着按照网站上说的做。在这不起作用之后，我尝试了一种更简单的方法，并尝试了网站所说的。这两种方法都会产生以下错误：

Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.

Check the render method of `AddScreen`.

---

My CodeSandbox链接：（Datepicker在/Screens/AddScreen.js中实现）

您的代码中有两个问题：

包不匹配：

相反，您需要使用这些：

"@date-io/date-fns": "v1",
    "@material-ui/core": "latest",
    "@material-ui/icons": "latest",
    "@material-ui/pickers": "latest",

要使用

KeyboardTimePicker

，您还需要提供不存在的

MuiPickersUtilsProvider

下面是添加屏幕的代码

import "date-fns";
import React from "react";
import Grid from "@material-ui/core/Grid";
import DateFnsUtils from "@date-io/date-fns";
import {
  MuiPickersUtilsProvider,
  KeyboardTimePicker,
  KeyboardDatePicker
} from "@material-ui/pickers";

export default function MaterialUIPickers() {
  // The first commit of Material-UI
  const [selectedDate, setSelectedDate] = React.useState(
    new Date("2014-08-18T21:11:54")
  );

  const handleDateChange = (date) => {
    setSelectedDate(date);
  };

  return (
    <MuiPickersUtilsProvider utils={DateFnsUtils}>
      <Grid container justify="space-around">
        <KeyboardDatePicker
          disableToolbar
          variant="inline"
          format="MM/dd/yyyy"
          margin="normal"
          id="date-picker-inline"
          label="Date picker inline"
          value={selectedDate}
          onChange={handleDateChange}
          KeyboardButtonProps={{
            "aria-label": "change date"
          }}
        />
        <KeyboardDatePicker
          margin="normal"
          id="date-picker-dialog"
          label="Date picker dialog"
          format="MM/dd/yyyy"
          value={selectedDate}
          onChange={handleDateChange}
          KeyboardButtonProps={{
            "aria-label": "change date"
          }}
        />
        <KeyboardTimePicker
          margin="normal"
          id="time-picker"
          label="Time picker"
          value={selectedDate}
          onChange={handleDateChange}
          KeyboardButtonProps={{
            "aria-label": "change time"
          }}
        />
      </Grid>
    </MuiPickersUtilsProvider>
  );
}

导入“日期fns”；
从“React”导入React；
从“@material ui/core/Grid”导入网格；
从“@date io/date fns”导入DateFnsUtils；
进口{
MuiPickersUtilsProvider，
键盘时间选择器，
键盘日期选择器
}来自“@物料界面/选择器”；
导出默认函数MaterialUIPackers（）{
//物料界面的第一次提交
常量[selectedDate，setSelectedDate]=React.useState(
新日期（“2014-08-18T21:11:54”）
);
const handleDateChange=（日期）=>{
设置选定日期（日期）；
};
返回(
);
}

---

下面是正在运行的演示：

您的代码中有两个问题：

包不匹配：

相反，您需要使用这些：

"@date-io/date-fns": "v1",
    "@material-ui/core": "latest",
    "@material-ui/icons": "latest",
    "@material-ui/pickers": "latest",

要使用

KeyboardTimePicker

，您还需要提供不存在的

MuiPickersUtilsProvider

下面是添加屏幕的代码

import "date-fns";
import React from "react";
import Grid from "@material-ui/core/Grid";
import DateFnsUtils from "@date-io/date-fns";
import {
  MuiPickersUtilsProvider,
  KeyboardTimePicker,
  KeyboardDatePicker
} from "@material-ui/pickers";

export default function MaterialUIPickers() {
  // The first commit of Material-UI
  const [selectedDate, setSelectedDate] = React.useState(
    new Date("2014-08-18T21:11:54")
  );

  const handleDateChange = (date) => {
    setSelectedDate(date);
  };

  return (
    <MuiPickersUtilsProvider utils={DateFnsUtils}>
      <Grid container justify="space-around">
        <KeyboardDatePicker
          disableToolbar
          variant="inline"
          format="MM/dd/yyyy"
          margin="normal"
          id="date-picker-inline"
          label="Date picker inline"
          value={selectedDate}
          onChange={handleDateChange}
          KeyboardButtonProps={{
            "aria-label": "change date"
          }}
        />
        <KeyboardDatePicker
          margin="normal"
          id="date-picker-dialog"
          label="Date picker dialog"
          format="MM/dd/yyyy"
          value={selectedDate}
          onChange={handleDateChange}
          KeyboardButtonProps={{
            "aria-label": "change date"
          }}
        />
        <KeyboardTimePicker
          margin="normal"
          id="time-picker"
          label="Time picker"
          value={selectedDate}
          onChange={handleDateChange}
          KeyboardButtonProps={{
            "aria-label": "change time"
          }}
        />
      </Grid>
    </MuiPickersUtilsProvider>
  );
}

导入“日期fns”；
从“React”导入React；
从“@material ui/core/Grid”导入网格；
从“@date io/date fns”导入DateFnsUtils；
进口{
MuiPickersUtilsProvider，
键盘时间选择器，
键盘日期选择器
}来自“@物料界面/选择器”；
导出默认函数MaterialUIPackers（）{
//物料界面的第一次提交
常量[selectedDate，setSelectedDate]=React.useState(
新日期（“2014-08-18T21:11:54”）
);
const handleDateChange=（日期）=>{
设置选定日期（日期）；
};
返回(
);
}

以下是工作演示：