react怎么实现表头固定

components/ScrollableTable/interface.tsx

import * as React from 'react';
export declare type AlignType = 'left' | 'center' | 'right';
export interface ColumnType {
  align?: AlignType;
  className?: string;
  dataKey?: string;
  fixed?: boolean;
  title?: React.ReactNode;
  width?: number;
  render?: (value: any, record: any, index: number) => React.ReactNode;
}
export interface TableProps {
  className?: string;
  style?: React.CSSProperties;
  columns?: ColumnType[];
  dataSource?: any[];
  width?: number;
  height?: number;
}

components/ScrollableTable/index.tsx

import React, { FunctionComponent, useRef } from 'react';
import { TableProps, ColumnType } from './interface';
import './index.less';
const ScrollableTable: FunctionComponent<any> = (props: TableProps) => {
  const style: React.CSSProperties = props.style || {};
  const maxHeight: string = props.width ? (props.height + &#39;px&#39;) : &#39;unset&#39;;
  const columns: ColumnType[] = props.columns || [];
  const dataSource: any[] = props.dataSource || [];
  let maxWidth: number = 0;
  if (props.width) style.width = props.width;
  if (columns.length === 0) {
    columns.push({
      dataKey: &#39;key&#39;
    });
  }
  columns.forEach((column: ColumnType) => {
    const width: number = column.width || 50;
    maxWidth += width;
  });
  const fixedColumns: number[][] = getFixedColumns(columns);
  const leftFixedColumns: number[] = fixedColumns[0];
  const rightFixedColumns: number[] = fixedColumns[1];
  const tableBody: any = useRef();
  const handleScroll = (target: any) => {
    const scrollLeft: number = target.scrollLeft;
    const tableHeaders: any = target.parentElement.getElementsByClassName(&#39;st-table-header&#39;);
    if (tableHeaders.length > 0) {
      tableHeaders[0].scrollLeft = scrollLeft;
    }
  };
  return (
    <div
      className={classNames(&#39;st-table-container&#39;, props.className)}
      style={style}
    >
      <div className="st-table-header">
        <table>
          <colgroup>
            {
              renderCols(columns)
            }
          </colgroup>
          <thead className="st-table-thead">
            <tr>
              {
                columns.map((column: ColumnType, index: number) => {
                  const align: any = column.align || undefined;
                  const title: React.ReactNode = column.title || &#39;&#39;;
                  const fixed: string = leftFixedColumns.includes(index) ? &#39;left&#39; : (rightFixedColumns.includes(index) ? &#39;right&#39; : &#39;&#39;);
                  const fixedClassName: string = fixed ? (&#39;st-table-cell-fix-&#39; + fixed) : &#39;&#39;;
                  return (
                    <th
                      key={index}
                      className={classNames(&#39;st-table-cell&#39;, fixedClassName, column.className)}
                      style={{textAlign: align}}
                    >
                      {title}
                    </th>
                  );
                })
              }
            </tr>
          </thead>
        </table>
      </div>
      <div
        ref={tableBody}
        className="st-table-body"
        style={{maxHeight: maxHeight}}
        onScroll={(e: any) => handleScroll(e.currentTarget)}
      >
        <table style={{width: maxWidth, minWidth: &#39;100%&#39;}}>
          <colgroup>
              {
                renderCols(columns)
              }
            </colgroup>
            <tbody className="st-table-tbody">
              {
                dataSource.map((record: any, index: number) => (
                  <tr key={index} className="st-table-row">
                    {
                      renderCells(columns, leftFixedColumns, rightFixedColumns, record, index)
                    }
                  </tr>
                ))
              }
            </tbody>
        </table>
      </div>
    </div>
  );
};
function classNames(...names: (string | undefined)[]) {
  const currentNames: string[] = [];
  names.forEach((name: (string | undefined)) => {
    if (name) currentNames.push(name);
  });
  return currentNames.join(&#39; &#39;);
}
function getFixedColumns(columns: ColumnType[]) {
  const total: number = columns.length;
  const leftFixedColumns: number[] = [];
  const rightFixedColumns: number[] = [];
  if (columns[0].fixed) {
    for (let i = 0; i < total; i++) {
      if (columns[i].fixed) {
        leftFixedColumns.push(i);
      } else {
        break;
      }
    }
  }
  if (columns[total - 1].fixed) {
    for (let i = total - 1; i >= 0; i--) {
      if (columns[i].fixed) {
        if (!leftFixedColumns.includes(i)) rightFixedColumns.push(i);
      } else {
        break;
      }
    }
  }
  return [leftFixedColumns, rightFixedColumns];
}
function renderCols(columns: ColumnType[]) {
  return columns.map((column: ColumnType, index: number) => {
    const width: number = column.width || 50;
    return (
      <col
        key={index}
        style={{width: width, minWidth: width}}
      />
    );
  });
}
function renderCells(columns: ColumnType[], leftFixedColumns: number[], rightFixedColumns: number[], record: any, index: number) {
  return columns.map((column: ColumnType, index: number) => {
    const align: any = column.align || undefined;
    const fixed: string = leftFixedColumns.includes(index) ? &#39;left&#39; : (rightFixedColumns.includes(index) ? &#39;right&#39; : &#39;&#39;);
    const className: string = classNames(&#39;st-table-cell&#39;, column.className, fixed ? (&#39;st-table-cell-fix-&#39; + fixed) : &#39;&#39;);
    const rawValue: any = (column.dataKey && column.dataKey in record) ? record[column.dataKey] : undefined;
    let value: any = undefined;
    if (column.render) {
      value = column.render(rawValue, record, index);
    } else {
      value = (rawValue === undefined || rawValue === null) ? &#39;&#39; : String(rawValue);
    }
    return (
      <td
        key={index}
        className={className}
        style={{textAlign: align}}
      >
        {value}
      </td>
    );
  });
}
export default ScrollableTable;

components/ScrollableTable/index.less

.st-table-container {
  border: 1px solid #f0f0f0;
  border-right: 0;
  border-bottom: 0;
  font-size: 14px;
  .st-table-header {
    border-right: 1px solid #f0f0f0;
    overflow: hidden;
    table {
      border-collapse: separate;
      border-spacing: 0;
      table-layout: fixed;
      width: 100%;
      thead.st-table-thead {
        tr {
          th.st-table-cell {
            background: #fafafa;
            border-bottom: 1px solid #f0f0f0;
            border-right: 1px solid #f0f0f0;
            color: rgba(0, 0, 0, .85);
            font-weight: 500;
            padding: 8px;
            text-align: left;
            &:last-child {
              border-right: 0;
            }
          }
        }
      }
    }
  }
  .st-table-body {
    overflow: auto scroll;
    border-bottom: 1px solid #f0f0f0;
    border-right: 1px solid #f0f0f0;
    table {
      border-collapse: separate;
      border-spacing: 0;
      table-layout: fixed;
      tbody.st-table-tbody {
        tr.st-table-row {
          td.st-table-cell  {
            border-bottom: 1px solid #f0f0f0;
            border-right: 1px solid #f0f0f0;
            color: rgba(0, 0, 0, .65);
            padding: 8px;
            text-align: left;
            &:last-child {
              border-right: 0;
            }
          }
          &:last-child {
            td.st-table-cell  {
              border-bottom: 0;
            }
          }
        }
      }
    }
  }
  table {
    .st-table-cell {
      &.st-table-cell-fix-left {
        background: #fff;
        position: sticky;
        left: 0;
        z-index: 2;
      }
      &.st-table-cell-fix-right {
        background: #fff;
        position: sticky;
        right: 0;
        z-index: 2;
      }
    }
  }
}

views/Test/index.tsx
import React, { FunctionComponent } from 'react';
import Page from '../../components/Page';
import ScrollableTable from '../../components/ScrollableTable';
import StoreProvider from '../../stores/products/context';
import './index.less';
const Test: FunctionComponent<any> = (props: any) => {
  let records: any[] = [{
    id: 1,
    productName: &#39;淡泰&#39;,
    amount1: 198,
    amount2: 200,
    amount3: 205.5,
    currency: &#39;人民币&#39;,
    ca: &#39;Amy&#39;
  }, {
    productName: &#39;方润&#39;,
    amount1: 105.5,
    amount2: 100,
    amount3: 108,
    currency: &#39;港元&#39;,
    ca: &#39;Baby&#39;
  }, {
    productName: &#39;医疗基金-1&#39;,
    amount1: 153,
    amount2: 150,
    amount3: 155,
    currency: &#39;人民币&#39;,
    ca: &#39;Emily&#39;
  }, {
    productName: &#39;医疗基金-2&#39;,
    amount1: 302,
    amount2: 300,
    amount3: 290,
    currency: &#39;美元&#39;,
    ca: &#39;Baby&#39;
  }, {
    productName: &#39;医疗基金-3&#39;,
    amount1: 108.8,
    amount2: 100,
    amount3: 130,
    currency: &#39;人民币&#39;,
    ca: &#39;Amy&#39;
  }, {
    productName: &#39;医疗基金-4&#39;,
    amount1: 205,
    amount2: 200,
    amount3: 208,
    currency: &#39;美元&#39;,
    ca: &#39;吴丹&#39;
  }, {
    productName: &#39;医疗基金-5&#39;,
    amount1: 315.5,
    amount2: 300,
    amount3: 280,
    currency: &#39;人民币&#39;,
    ca: &#39;Baby&#39;
  }, {
    productName: &#39;医疗基金-6&#39;,
    amount1: 109,
    amount2: 95,
    amount3: 106,
    currency: &#39;人民币&#39;,
    ca: &#39;Emily&#39;
  }, {
    productName: &#39;恒大私募债&#39;,
    amount1: 213,
    amount2: 200,
    amount3: 208,
    currency: &#39;港元&#39;,
    ca: &#39;吴丹&#39;
  }];
  const totalRecord: any = {
    productName: &#39;合计&#39;,
    amount1: {},
    amount2: {},
    amount3: {}
  };
  records.forEach((record: any) => {
    const currency: string = record.currency;
    [&#39;amount1&#39;, &#39;amount2&#39;, &#39;amount3&#39;].forEach((key: string) => {
      const value: any = totalRecord[key];
      if (!(currency in value)) value[currency] = 0;
      value[currency] += record[key];
    });
  });
  records.push(totalRecord);
  const columns: any[] = [{
    dataKey: &#39;productName&#39;,
    title: &#39;产品名称&#39;,
    width: 90,
    fixed: true
  }, {
    dataKey: &#39;amount1&#39;,
    title: <React.Fragment>上周缴款金额<br/>（万）</React.Fragment>,
    width: 140,
    align: &#39;center&#39;,
    className: &#39;amount&#39;,
    render: calculateTotal
  }, {
    dataKey: &#39;amount2&#39;,
    title: <React.Fragment>上周预约金额<br/>（万）</React.Fragment>,
    width: 140,
    align: &#39;center&#39;,
    className: &#39;amount&#39;,
    render: calculateTotal
  }, {
    dataKey: &#39;amount3&#39;,
    title: <React.Fragment>待本周跟进金额<br/>（万）</React.Fragment>,
    width: 140,
    align: &#39;center&#39;,
    className: &#39;amount&#39;,
    render: calculateTotal
  }, {
    dataKey: &#39;currency&#39;,
    title: &#39;币种&#39;,
    width: 80
  }, {
    dataKey: &#39;ca&#39;,
    title: &#39;CA&#39;,
    width: 80
  }];
  return (
    <StoreProvider>
      <Page
        {...props}
        title="销售统计"
        className="test"
      >
        <div style={{padding: 15}}>
          <ScrollableTable
            width={window.innerWidth - 30}
            height={196}
            columns={columns}
            dataSource={records}
          />
        </div>
      </Page>
    </StoreProvider>
  );
};
function calculateTotal(value: any) {
  if (value instanceof Object) {
    const keys: any[] = Object.keys(value);
    return (
      <React.Fragment>
        {
          keys.map((key: string, index: number) => (
            <span key={index}>
              {`${value[key].toFixed(2)}万${key}`}
            </span>
          ))
        }
      </React.Fragment>
    )
  }
  return value.toFixed(2);
}
export default Test;

views/Test/index.less

.st-table-container {
  .st-table-body {
    td.st-table-cell.amount {
      padding-right: 20px !important;
      text-align: right !important;
      span {
        display: block;
      }
    }
  }
}