js实现输入高亮@和#后面的内容

效果如下：支持连续输入

<!DOCTYPE html>
<html lang="zh-CN">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title></title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      min-height: 100vh;
      display: flex;
      justify-content: center;
      align-items: center;
      padding: 20px;
    }

    .container {
      width: 100%;
      max-width: 800px;
      background: white;
      border-radius: 16px;
      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
      overflow: hidden;
    }

    .content {
      padding: 30px;
    }

    .editor-container {
      position: relative;
      margin-bottom: 30px;
    }

    #editor {
      min-height: 200px;
      border: 2px solid #e0e0e0;
      border-radius: 8px;
      padding: 15px;
      font-size: 16px;
      line-height: 1.6;
      outline: none;
      transition: border-color 0.3s;
      background: white;
      overflow-y: auto;
    }

    #editor:focus {
      border-color: #3498db;
      box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
    }

    .highlight {
      background-color: #fff9c4;
      border-radius: 3px;
      padding: 0 2px;
      color: #e74c3c;
      font-weight: 500;
    }
  </style>
</head>

<body>
  <div class="container">
    <div class="content">
      <div class="editor-container">
        <div id="editor" contenteditable="true" placeholder="输入内容..."></div>
      </div>
    </div>
  </div>

  <script>
    const editor = document.getElementById('editor');
    function saveCursorPosition() {
      const selection = window.getSelection();
      if (selection.rangeCount === 0) return null;
      const range = selection.getRangeAt(0);
      const preCaretRange = range.cloneRange();
      preCaretRange.selectNodeContents(editor);
      preCaretRange.setEnd(range.endContainer, range.endOffset);
      return {
        startOffset: preCaretRange.toString().length,
        range: range
      };
    }
    function restoreCursorPosition(startOffset) {
      const selection = window.getSelection();
      selection.removeAllRanges();
      let charCount = 0;
      let nodeStack = [editor];
      let node, foundStart = false;
      let range = document.createRange();
      range.setStart(editor, 0);
      range.collapse(true);
      while (!foundStart && (node = nodeStack.pop())) {
        if (node.nodeType === Node.TEXT_NODE) {
          const nextCharCount = charCount + node.length;
          if (!foundStart && startOffset >= charCount && startOffset <= nextCharCount) {
            range.setStart(node, startOffset - charCount);
            foundStart = true;
          }
          charCount = nextCharCount
        } else {
          const children = node.childNodes;
          for (let i = children.length - 1; i >= 0; i--) {
            nodeStack.push(children[i])
          }
        }
      }

      if (foundStart) {
        range.collapse(true);
        selection.addRange(range);
      }
    }

    function applyHighlighting() {
      const cursorPosition = saveCursorPosition();
      const text = editor.textContent;
      const tags = [];
      editor.innerHTML = text.replace(/([@#][^\s]+)/g, (match) => {
        tags.push(match);
        return `<span class="highlight">${match}</span>`;
      });
      // 恢复光标位置
      if (cursorPosition) {
        restoreCursorPosition(cursorPosition.startOffset);
      }
    }

    let isComposing = false;
    editor.addEventListener('compositionstart', () => {
      isComposing = true;
    });

    editor.addEventListener('compositionend', () => {
      isComposing = false;
      applyHighlighting();
    });

    editor.addEventListener('input', () => {
      if (!isComposing) {
        applyHighlighting();
      }
    });
    applyHighlighting();
  </script>
</body>

</html>