React实现antdM的级联菜单实例

├─ src
│  ├─ App.js
│  ├─ components
│  │  └─ Cascader
│  │     ├─ CascaderContent // content部分
│  │     │  ├─ CascaderContent.js
│  │     │  └─ style.js
│  │     ├─ CascaderHead // head部分
│  │     │  ├─ CascaderHead.js
│  │     │  └─ style.js
│  │     ├─ index.js // 入口
│  │     ├─ style.js
│  │     ├─ Cascader.js
│  │     └─ testData // 测试数据
│  │        └─ data.js
│  ├─ index.css
│  └─ index.js

import React, { useMemo, useState } from "react";
import { useCallback, useEffect } from "react";
import { Wrapper } from "./style";
const classPrefix = `antdm-cascader-view`
export const CascaderContent = function ({ visible = false, ...props }) {
  // 当前页
  const [tabActiveIndex, setTabActiveIndex] = useState(0);
  // 初始值
  const [value, setValue] = useState(props.value || props.defaultValue || []);
  // loading效果
  const [loading, setLoading] = useState(true);
  const levels = useMemo(() => {
    const ret = []
    let currentOptions = props.options
    let reachedEnd = false
    for (const v of value) {
      const target = currentOptions.find(option => option.value === v)
      ret.push({
        selected: target,
        options: currentOptions,
      })
      // 没有下一项的时候中止遍历
      if (!target || !Array.isArray(target.children) || target.children.length === 0) {
        reachedEnd = true
        break
      }
      currentOptions = target.children
    }
    if (!reachedEnd) {
      ret.push({
        selected: undefined,
        options: currentOptions,
      })
    }
    return ret;
  }, [props.options, value])
  // 点击选项的时候
  const onChange = useCallback((item, index) => {
    if (item?.disabled) {
      return
    }
    const newValue = [...value.slice(0, index), item.value];
    setValue(newValue);
    props.onSelect?.(newValue)
  }, [value, props.onSelect])
  // 选中数据后，切换下一级菜单
  useEffect(() => {
    const max = levels.length - 1
    if (tabActiveIndex > max) {
      setTabActiveIndex(max)
    }
  }, [tabActiveIndex, levels])
  useEffect(() => {
    setTabActiveIndex(levels.length - 1)
  }, [value])
  useEffect(() => {
    if (visible) {
      setValue(props.value || props.defaultValue || []);
    }
  }, [visible])
  useEffect(() => {
    setValue(props.value || props.defaultValue || [])
  }, [props.value, props.defaultValue])
  // 设置定时器，使用loading效果
  useEffect(() => {
    const timer = setTimeout(() => {
      if (props.options?.length === 0) {
        setLoading(false)
      }
      return () => {
        clearTimeout(timer)
      }
    }, 3000);
  }, [])
  // 数据加载完毕后取消loading效果
  useEffect(() => {
    if (props.options.length !== 0) {
      setLoading(false)
    }
  }, [props.options])
  return <Wrapper>
    <div className={classPrefix}>
      <div className={`${classPrefix}-tabs`}>
        {levels.map((item, index) => {
          return <div
            key={index}
            onClick={() => { setTabActiveIndex(index) }}
            className={`${classPrefix}-tab ${tabActiveIndex === index && classPrefix + "-tab-active"}`}>
            {item?.selected?.label ? item?.selected?.label : item?.selected?.label === "" ? "" : "请选择"}
          </div>
        })}
      </div>
      <div className={`${classPrefix}-content`}>
        {!loading ? levels.map((item, index) => {
          return <div
            key={index.toString()}
            style={{ display: index === tabActiveIndex ? "block" : "none" }}
            className={`${classPrefix}-list`} >
            {item.options.map((o, i) => {
              return <div key={i.toString()} className={`${classPrefix}-item ${o.value === item?.selected?.value && classPrefix + "-item-active"}`}>
                <div
                  onClick={() => onChange(o, index)}
                  className={`${classPrefix}-item-main ${o?.disabled && classPrefix + "-item-disabled"}`}>
                  {o.label}
                </div>
                {o.value === item?.selected?.value && <div className={`${classPrefix}-item-extra`}>✓</div>}
              </div>
            })}
          </div>
        }) : "loading..."}
      </div>
    </div>
  </Wrapper>
}

import React from "react";
import { Wrapper } from "./style";
const classPrefix = `antdm-cascader`
export const CascaderHead = function (props) {
  return <Wrapper>
    <div className={classPrefix}>
      <div className={`${classPrefix}-header`}>
        <a
          className={`${classPrefix}-header-button`}
          onClick={() => {
            props.onCancel?.()
          }}
        >
          {props.cancelText || "取消"}
        </a>
        <div className={`${classPrefix}-header-title`}>{props.title}</div>
        <a
          className={`${classPrefix}-header-button ${props.canCommit ? '' : classPrefix + '-header-confirm-disable'}`}
          onClick={() => {
            props.canCommit && props.onConfirm?.();
          }}
        >
          {props.confirmText || "确定"}
        </a>
      </div>
    </div>
  </Wrapper>
}

import React, { useState, useCallback, useEffect } from "react";
import { Popup } from "antd-mobile";
import { CascaderHead } from "./CascaderHead/CascaderHead";
import { CascaderContent } from "./CascaderContent/CascaderContent";
import { Wrapper } from "./style";
export const CascaderModal = function (props) {
  const [value, setValue] = useState(props.value || props.defaultValue || []);
  const [canCommit, setCanCommit] = useState(false);
  const onChange = useCallback((v) => {
    setValue(v);
    props.onSelect?.(v)
  }, [props.onSelect])
  // 将选择的数据提交出去
  const onConfirm = useCallback(() => {
    props.onConfirm?.(value)
  }, [props.onConfirm, value])
  // 取消
  const onCancel = useCallback(() => {
    props.onCancel?.()
  }, [props.onCancel])
  useEffect(() => {
    if (value.length === 0) {
      return;
    }
    let children = props.options;
    let i = 0;
    for (i; i < value.length; i++) {
      const obj = children.find(item => item.value === value[i]);
      if (!obj) {
        children = undefined;
        break;
      } else {
        children = obj.children
      }
    }
    setCanCommit(!Array.isArray(children) || children.length === 0)
  }, [value, props.options])
  useEffect(() => {
    setValue(props.value || props.defaultValue || [])
  }, [props.value, props.defaultValue])
  useEffect(() => {
    if (props.visible) {
      setCanCommit(false);
    }
  }, [props.visible])
  return <Wrapper>
    <Popup
      className="antdm-cascader-modal"
      visible={props.visible}
      onClose={onCancel}
      animationType="slide-up"
      popup={true}
    >
      <CascaderHead {...props} canCommit={canCommit} onCancel={onCancel} onConfirm={onConfirm} />
      <CascaderContent {...props} visible={props.visible} onSelect={onChange} />
    </Popup>
  </Wrapper>
}