d3js阻止事件

<section class="core-concept">
    <h3>事件传播核心机制</h3>
    <div class="mechanism-diagram">
        <div class="event-flow">
            <span>捕获阶段</span>
            <svg width="100%" height="30">
                <path d="M 0 15 L 100 15" stroke="#4CAF50"></path>
            </svg>
            <span>目标阶段</span>
            <svg width="100%" height="30">
                <path d="M 0 15 L 100 15" stroke="#2196F3"></path>
            </svg>
            <span>冒泡阶段</span>
        </div>
    </div>
    <p>浏览器事件传播包含三个阶段：捕获→目标→冒泡，理解这个机制是掌握事件控制的基础。</p>
</section>
<section class="practice-section">
    <h3>实战解决方案</h3>
    <div class="code-example">
        <h4>1. 阻止事件冒泡</h4>
        <pre><code class="language-javascript">d3.select("#element")
.on("click", function(event) {
    d3.event.stopPropagation();
    // 业务逻辑代码
    console.log("元素点击事件已执行");
});</code></pre>
    </div>
    <div class="code-example">
        <h4>2. 禁止默认行为</h4>
        <pre><code class="language-javascript">d3.select("a.link")
.on("click", function(event) {
    d3.event.preventDefault();
    // 自定义导航逻辑
    handleCustomNavigation();
});</code></pre>
    </div>
    <div class="case-study">
        <h4>典型应用场景</h4>
        <ul class="case-list">
            <li>嵌套元素中的独立交互控制</li>
            <li>自定义右键菜单实现</li>
            <li>拖拽操作中的冲突避免</li>
            <li>表单验证失败时的提交阻止</li>
        </ul>
    </div>
</section>
<section class="qa-section">
    <h3>开发者常见问题解答</h3>
    <div class="qa-item">
        <p class="question">Q：如何同时阻止冒泡和默认行为？</p>
        <div class="answer">
            <pre><code class="language-javascript">d3.event
.stopPropagation()
.preventDefault();</code></pre>
        </div>
    </div>
    <div class="qa-item">
        <p class="question">Q：动态生成元素如何绑定事件控制？</p>
        <div class="answer">
            <p>推荐使用事件委托模式：</p>
            <pre><code class="language-javascript">d3.select("body")
.on("click", ".dynamic-element", function() {
    d3.event.stopPropagation();
    // 处理动态元素逻辑
});</code></pre>
        </div>
    </div>
</section>
<section class="best-practice">
    <h3>性能优化建议</h3>
    <ul class="optimization-tips">
        <li>避免在频繁触发的事件(如mousemove)中使用阻止</li>
        <li>使用CSS的<code>pointer-events</code>属性辅助控制</li>
        <li>及时移除不需要的事件监听器</li>
        <li>优先使用被动事件监听器提升滚动性能</li>
    </ul>
</section>
<div class="reference-section">
    <h3>参考文献</h3>
    <ul>
        <li>D3.js官方文档 - Event Handling</li>
        <li>MDN Web Docs - Event.stopPropagation()</li>
        <li>Google Developer - Event Optimization</li>
    </ul>
</div>
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