JavaScript：如何在表格中设置拖放步骤答案

【问题标题】：JavaScript: how to set drag-and-drop step in tableJavaScript：如何在表格中设置拖放步骤
【发布时间】：2017-08-03 10:30:14
【问题描述】：

我有这样的代码：

<div class="table-area">
  <table>
    <thead>
      <tr>
      <th>someDate</th>
      <th>1</th>
      <th>2</th>
      <th>3</th>
      </tr>
    </thead>

    <tbody>
      <tr>
        <td>someDateVal1</td>
        <td class="data-cell"></td>
        <td class="data-cell"></td>
        <td class="data-cell"></td>
      </tr>
      <tr>
        <td>someDateVal2</td>
        <td class="data-cell"></td>
        <td class="data-cell"></td>
        <td class="data-cell"></td>
      </tr>
    </tbody>
  </table>

  <div class="table-area-selected"
    draggable="true"></div>
</div>

和js：

$(function() {

  var selected = $('.table-area-selected');

  var cell = $('table').find('.data-cell');


  selected.css('width', $(cell[0]).outerWidth() * 2);
  selected.css('height', $(cell[0]).outerHeight());


  selected.css('top', $(cell[0]).position().top);
  selected.css('left', $(cell[0]).position().left);

  $('.table-area-selected').on('dragstart', function(event) {
    console.log('drag', event);
  });

  $('table').on('drop', function(event) {
    var selected = $('.table-area-selected');

    var cell = event.target;

    console.log('drop', event);


    selected.css('width', $(cell).outerWidth() * 2);
    selected.css('height', $(cell).outerHeight());


    selected.css('top', $(cell).position().top);
    selected.css('left', $(cell).position().left);
  });

  $('table').on('dragover', function(event) {
    event.preventDefault();
  });


});

https://plnkr.co/edit/NpRHbgHnUgGfgAOJnSTw?p=preview

是否可以像其他日程插件一样拖动这个项目？像这样：https://dhtmlx.com/docs/products/demoApps/room-reservation-html5-js-php/

因为现在我的矩形是空闲的。我需要在表格网格上设置它的动作：像这样： https://www.screencast.com/t/EXKQwTwTwkb 而不是这个： https://www.screencast.com/t/g6jbP4s9hBX2

可以吗？

【问题讨论】：

标签： javascript jquery html drag-and-drop

【解决方案1】：

在这种情况下，我个人不会使用 HTML 5 拖放，我会选择鼠标事件。

请注意，我写的是 2 列跨度；如果您希望它更灵活，则需要对其进行调整。

$(function() {

  var isDragging = false;

  var $selected = $('.table-area-selected');

  var $cells = $('table').find('.data-cell');
  var colSpan = 2;
  var $currentCell = $($cells[0]);
  var cellWidth = $currentCell.outerWidth();

  $selected.css('width', cellWidth * colSpan);
  $selected.css('height', $currentCell.outerHeight() - 2); // fiddle factor
  $selected.css('top', $currentCell.position().top);
  $selected.css('left', $currentCell.position().left);

  // drag start
  $selected.mousedown(dragStart);

  // drag end
  $(window).mouseup(dragEnd);

  // drag over cells
  $cells.mouseenter(draggingIntoNewCell);
  $selected.mousemove(draggingInSelectedCell);


  function dragStart() {
    isDragging = true;
  }

  function dragEnd() {
    isDragging = false;
  }

  function draggingIntoNewCell() {
    $currentCell = $(this);
    reposition($currentCell);
  }

  // find if we've moved into the next column under this selection
  function draggingInSelectedCell(e) {

    if (isDragging) {

      // find relative position within selection div
      var relativeXPosition = (e.pageX - $(this).offset().left);

      if (relativeXPosition > cellWidth) { // moved into next column
        $currentCell = $currentCell.next();
        reposition($currentCell);
      }
    }
  }

  function reposition($cell) {

    // only reposition if not the last cell in the table (otherwise can't span 2 cols)    
    if (isDragging && $cell.next().hasClass('data-cell')) {
      $selected.css('top', $cell.position().top);
      $selected.css('left', $cell.position().left);
    }
  }

});

table th,
table td {
  padding: 8px 40px;
  border: 1px solid #cecece;
  position: relative;
  -moz-user-select: none;
  -webkit-user-select: none;
  -ms-user-select: none;
}

.table-area-selected {
  position: absolute;
  background: green;
  border: 1px solid blue;
  cursor: pointer;
}

<!DOCTYPE html>
<html>

<head>
  <script data-require="jquery@*" data-semver="3.1.1" src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
</head>

<body>
  <h1>Hello Plunker!</h1>

  <div class="table-area">
    <table>
      <thead>
        <tr>
          <th>someDate</th>
          <th>1</th>
          <th>2</th>
          <th>3</th>
          <th>4</th>
        </tr>
      </thead>

      <tbody>
        <tr>
          <td>someDateVal1</td>
          <td class="data-cell"></td>
          <td class="data-cell"></td>
          <td class="data-cell"></td>
          <td class="data-cell"></td>
        </tr>
        <tr>
          <td>someDateVal2</td>
          <td class="data-cell"></td>
          <td class="data-cell"></td>
          <td class="data-cell"></td>
          <td class="data-cell"></td>
        </tr>
      </tbody>
    </table>

    <div class="table-area-selected"></div>
  </div>
</body>

</html>

演示：http://plnkr.co/edit/RIhDiu9bI00SJysKvMuu?p=preview

【讨论】：

我最初使用 HTML Drag & Drop 尝试过这个，但找不到任何方法让它做你想要的。

【解决方案2】：

只是一个更简单的示例，但您可以使用多个选择框。 Colspan 可以与 .data-cell 大小相关。我还添加了user-select: none; css 属性以避免在拖动时随机选择文本。

$(function() {
  var dragging = false;
  var selected = null;
  var cell = $('table').find('.data-cell');

  $('.table-area-selected').each(function(index) {
    $(this).css('top', $(cell.get(index)).position().top);
    $(this).css('left', $(cell.get(index)).position().left);

    $(this).css('width', $(cell.get(index)).innerWidth());
    $(this).css('height', $(cell.get(index)).innerHeight());
  });

  $('.table-area-selected').on('mousedown', function(event) {
    console.log('mousedown');
    selected = $(this);
    dragging = true;

  });

  $(window).on('mouseup', function(event) {
    console.log('mouseup');
    selected = null;
    dragging = false;
  });

  $('.data-cell').on('mouseover', function(event) {
    var cell = $(this);
    if (dragging) {
      selected.css('top', cell.position().top);
      selected.css('left', cell.position().left);

      selected.css('width', cell.innerWidth());
      selected.css('height', cell.innerHeight());
      console.log('dragged a selection box : ' + selected);
    }
  });

});

table th,
table td {
  padding: 10px 50px;
  border: 1px solid #cecece;
}

.table-area {
  position: relative;
  -webkit-user-select: none;
  /* Chrome, Opera, Safari */
  -moz-user-select: none;
  /* Firefox 2+ */
  -ms-user-select: none;
  /* IE 10+ */
  user-select: none;
  /* Standard syntax */
}

.table-area-selected {
  position: absolute;
  background: green;
  border: 1px solid blue;
  cursor: pointer;
}

.data-cell {}

<!DOCTYPE html>
<html>

<head>
  <script data-require="jquery@*" data-semver="3.1.1" src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
  <link rel="stylesheet" href="style.css" />
  <script src="script.js"></script>
</head>

<body>
  <h1>Hello Plunker!</h1>

  <div class="table-area">
    <table>
      <thead>
        <tr>
          <th>someDate</th>
          <th>1</th>
          <th>2</th>
          <th>3</th>
        </tr>
      </thead>

      <tbody>
        <tr>
          <td>someDateVal1</td>
          <td class="data-cell"></td>
          <td class="data-cell"></td>
          <td class="data-cell"></td>
        </tr>
        <tr>
          <td>someDateVal2</td>
          <td class="data-cell"></td>
          <td class="data-cell"></td>
          <td class="data-cell"></td>
        </tr>
      </tbody>
    </table>

    <div class="table-area-selected"></div>
    <div class="table-area-selected"></div>
  </div>
</body>

</html>

【讨论】：