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test-repo/docs/.vitepress/theme/components/appendix/component-state-management/EventBusDemo.vue
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<template>
<div class="event-bus-demo">
<div class="demo-header">
<h4>事件总线通信演示</h4>
<p class="hint">观察多个独立组件如何通过事件总线进行通信注意内存管理的重要性</p>
</div>
<div class="architecture-view">
<div class="central-hub" :class="{ active: isTransmitting }">
<div class="hub-core">
<div class="hub-icon">🔌</div>
<div class="hub-label">Event Bus</div>
<div class="hub-status">{{ isTransmitting ? '传输中...' : '待机' }}</div>
</div>
<div class="hub-rings">
<div class="ring ring-1"></div>
<div class="ring ring-2"></div>
<div class="ring ring-3"></div>
</div>
</div>
<div class="connected-components">
<div
v-for="comp in components"
:key="comp.id"
class="component-node"
:class="{ active: comp.isActive, emitting: comp.isEmitting, listening: comp.isListening }"
:style="{ top: comp.y + '%', left: comp.x + '%' }"
>
<div class="node-header">
<span class="node-icon">{{ comp.icon }}</span>
<span class="node-name">{{ comp.name }}</span>
</div>
<div class="node-status">
<span class="status-dot" :class="{ active: comp.isListening }"></span>
{{ comp.isListening ? '监听中' : '未监听' }}
</div>
<button class="emit-btn" @click="emitEvent(comp)">
发送事件
</button>
</div>
</div>
<svg class="connection-lines" viewBox="0 0 100 100" preserveAspectRatio="none">
<defs>
<marker id="arrowhead" markerWidth="6" markerHeight="6" refX="5" refY="3" orient="auto">
<polygon points="0 0, 6 3, 0 6" :fill="isTransmitting ? 'var(--vp-c-brand)' : 'var(--vp-c-divider)'" />
</marker>
</defs>
<line
v-for="(comp, index) in components"
:key="index"
class="connection-line"
:class="{ active: comp.isEmitting || isTransmitting }"
:x1="comp.x"
:y1="comp.y"
x2="50"
y2="50"
marker-end="url(#arrowhead)"
/>
</svg>
</div>
<div class="event-log">
<div class="log-header">
<h5>📨 事件日志</h5>
<button class="clear-btn" @click="clearLogs">清空</button>
</div>
<div class="log-content">
<div v-if="logs.length === 0" class="empty-log">
暂无事件记录点击组件上的"发送事件"按钮开始测试
</div>
<div
v-for="(log, index) in logs"
:key="index"
class="log-item"
:class="log.type"
>
<span class="log-time">{{ log.time }}</span>
<span class="log-type">{{ log.type === 'emit' ? '发送' : '接收' }}</span>
<span class="log-from">{{ log.from }}</span>
<span class="log-arrow"></span>
<span class="log-to">{{ log.to }}</span>
<span class="log-data">{{ log.data }}</span>
</div>
</div>
</div>
<div class="memory-warning">
<div class="warning-icon"></div>
<div class="warning-content">
<h6>内存泄漏风险提醒</h6>
<p>使用 Event Bus 如果组件销毁前没有取消订阅$off会导致内存泄漏推荐在 beforeUnmount 钩子中清理订阅</p>
<pre><code>// 正确做法
export default {
created() {
this.$bus.$on('event', this.handler)
},
beforeUnmount() {
this.$bus.$off('event', this.handler) // 必须取消订阅
}
}</code></pre>
</div>
</div>
</div>
</template>
<script setup>
import { ref, reactive, onBeforeUnmount } from 'vue'
// 组件定义
const components = reactive([
{ id: 1, name: 'Header', icon: '📌', x: 15, y: 15, isActive: false, isEmitting: false, isListening: true },
{ id: 2, name: 'Sidebar', icon: '📑', x: 85, y: 15, isActive: false, isEmitting: false, isListening: true },
{ id: 3, name: 'ProductList', icon: '🛍️', x: 15, y: 85, isActive: false, isEmitting: false, isListening: true },
{ id: 4, name: 'Cart', icon: '🛒', x: 85, y: 85, isActive: false, isEmitting: false, isListening: true }
])
const isTransmitting = ref(false)
const logs = ref([])
// 格式化时间
const formatTime = () => {
const now = new Date()
return `${now.getHours().toString().padStart(2, '0')}:${now.getMinutes().toString().padStart(2, '0')}:${now.getSeconds().toString().padStart(2, '0')}.${now.getMilliseconds().toString().padStart(3, '0')}`
}
// 添加日志
const addLog = (type, from, to, data) => {
logs.value.unshift({
type,
time: formatTime(),
from,
to,
data: JSON.stringify(data)
})
if (logs.value.length > 50) {
logs.value = logs.value.slice(0, 50)
}
}
// 发送事件
const emitEvent = (comp) => {
// 触发发送动画
comp.isEmitting = true
isTransmitting.value = true
// 记录发送日志
addLog('emit', comp.name, 'Event Bus', { event: 'user:action', payload: { from: comp.name } })
// 模拟其他组件接收
components.forEach(target => {
if (target.id !== comp.id && target.isListening) {
setTimeout(() => {
target.isActive = true
addLog('receive', 'Event Bus', target.name, { event: 'user:action', payload: { from: comp.name } })
setTimeout(() => {
target.isActive = false
}, 500)
}, 300 + Math.random() * 200)
}
})
// 清理动画状态
setTimeout(() => {
comp.isEmitting = false
isTransmitting.value = false
}, 1000)
}
// 清空日志
const clearLogs = () => {
logs.value = []
}
onBeforeUnmount(() => {
// 模拟清理订阅
components.forEach(comp => {
comp.isListening = false
})
})
</script>
<style scoped>
.event-bus-demo {
border: 1px solid var(--vp-c-divider);
border-radius: 8px;
padding: 20px;
background: var(--vp-c-bg-soft);
}
.demo-header {
margin-bottom: 20px;
}
.demo-header h4 {
margin: 0 0 8px 0;
color: var(--vp-c-text-1);
}
.hint {
margin: 0;
font-size: 14px;
color: var(--vp-c-text-2);
}
.architecture-view {
position: relative;
min-height: 400px;
background: var(--vp-c-bg);
border-radius: 8px;
padding: 20px;
margin-bottom: 20px;
overflow: hidden;
}
.central-hub {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
z-index: 10;
}
.hub-core {
position: relative;
z-index: 2;
width: 100px;
height: 100px;
background: linear-gradient(135deg, var(--vp-c-brand), var(--vp-c-brand-light));
border-radius: 50%;
display: flex;
flex-direction: column;
align-items: center;
justify-content: center;
box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
transition: all 0.3s ease;
}
.central-hub.active .hub-core {
transform: scale(1.1);
box-shadow: 0 0 30px var(--vp-c-brand);
}
.hub-icon {
font-size: 28px;
margin-bottom: 2px;
}
.hub-label {
font-size: 11px;
font-weight: 600;
color: white;
text-align: center;
}
.hub-status {
font-size: 9px;
color: rgba(255, 255, 255, 0.8);
margin-top: 2px;
}
.hub-rings {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
}
.ring {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
border: 2px solid var(--vp-c-divider);
border-radius: 50%;
opacity: 0.3;
transition: all 0.3s ease;
}
.central-hub.active .ring {
border-color: var(--vp-c-brand);
opacity: 0.6;
}
.ring-1 { width: 140px; height: 140px; }
.ring-2 { width: 180px; height: 180px; }
.ring-3 { width: 220px; height: 220px; }
.central-hub.active .ring-1 { animation: pulse1 1s ease infinite; }
.central-hub.active .ring-2 { animation: pulse2 1s ease infinite 0.2s; }
.central-hub.active .ring-3 { animation: pulse3 1s ease infinite 0.4s; }
@keyframes pulse1 {
0%, 100% { transform: translate(-50%, -50%) scale(1); opacity: 0.6; }
50% { transform: translate(-50%, -50%) scale(1.05); opacity: 0.3; }
}
@keyframes pulse2 {
0%, 100% { transform: translate(-50%, -50%) scale(1); opacity: 0.4; }
50% { transform: translate(-50%, -50%) scale(1.05); opacity: 0.2; }
}
@keyframes pulse3 {
0%, 100% { transform: translate(-50%, -50%) scale(1); opacity: 0.2; }
50% { transform: translate(-50%, -50%) scale(1.05); opacity: 0.1; }
}
.connected-components {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
pointer-events: none;
}
.component-node {
position: absolute;
background: var(--vp-c-bg);
border: 2px solid var(--vp-c-divider);
border-radius: 8px;
padding: 12px;
min-width: 120px;
pointer-events: auto;
transition: all 0.3s ease;
cursor: pointer;
}
.component-node:hover {
transform: translateY(-2px);
box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}
.component-node.active {
border-color: #22c55e;
background: #f0fdf4;
box-shadow: 0 0 0 3px #bbf7d0;
}
.component-node.emitting {
border-color: var(--vp-c-brand);
animation: emitPulse 0.5s ease;
}
@keyframes emitPulse {
0%, 100% { transform: scale(1); }
50% { transform: scale(1.05); }
}
.node-header {
display: flex;
align-items: center;
gap: 6px;
margin-bottom: 6px;
}
.node-icon {
font-size: 16px;
}
.node-name {
font-weight: 600;
font-size: 12px;
color: var(--vp-c-text-1);
}
.node-status {
display: flex;
align-items: center;
gap: 4px;
font-size: 11px;
color: var(--vp-c-text-2);
margin-bottom: 8px;
}
.status-dot {
width: 6px;
height: 6px;
border-radius: 50%;
background: var(--vp-c-divider);
transition: all 0.3s ease;
}
.status-dot.active {
background: #22c55e;
box-shadow: 0 0 4px #22c55e;
animation: blink 1.5s ease infinite;
}
@keyframes blink {
0%, 100% { opacity: 1; }
50% { opacity: 0.5; }
}
.emit-btn {
width: 100%;
padding: 6px 10px;
background: var(--vp-c-brand);
color: white;
border: none;
border-radius: 4px;
font-size: 11px;
cursor: pointer;
transition: all 0.2s ease;
}
.emit-btn:hover {
background: var(--vp-c-brand-dark);
}
.connection-lines {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
pointer-events: none;
}
.connection-line {
stroke: var(--vp-c-divider);
stroke-width: 2;
fill: none;
transition: all 0.3s ease;
}
.connection-line.active {
stroke: var(--vp-c-brand);
stroke-width: 3;
filter: drop-shadow(0 0 4px var(--vp-c-brand));
}
.event-log {
margin-top: 20px;
background: var(--vp-c-bg);
border: 1px solid var(--vp-c-divider);
border-radius: 8px;
overflow: hidden;
}
.log-header {
display: flex;
justify-content: space-between;
align-items: center;
padding: 12px 16px;
background: var(--vp-c-bg-soft);
border-bottom: 1px solid var(--vp-c-divider);
}
.log-header h5 {
margin: 0;
font-size: 14px;
color: var(--vp-c-text-1);
}
.clear-btn {
padding: 4px 12px;
background: transparent;
border: 1px solid var(--vp-c-divider);
border-radius: 4px;
font-size: 12px;
color: var(--vp-c-text-2);
cursor: pointer;
transition: all 0.2s ease;
}
.clear-btn:hover {
border-color: var(--vp-c-brand);
color: var(--vp-c-brand);
}
.log-content {
max-height: 200px;
overflow-y: auto;
padding: 8px;
}
.empty-log {
text-align: center;
padding: 40px;
color: var(--vp-c-text-3);
font-size: 13px;
}
.log-item {
display: flex;
align-items: center;
gap: 8px;
padding: 8px 12px;
margin-bottom: 4px;
border-radius: 4px;
font-size: 12px;
font-family: monospace;
animation: slideIn 0.3s ease;
}
@keyframes slideIn {
from {
opacity: 0;
transform: translateX(-10px);
}
to {
opacity: 1;
transform: translateX(0);
}
}
.log-item.emit {
background: #eff6ff;
border-left: 3px solid #3b82f6;
}
.log-item.receive {
background: #f0fdf4;
border-left: 3px solid #22c55e;
}
.log-time {
color: var(--vp-c-text-3);
font-size: 11px;
}
.log-type {
padding: 2px 6px;
border-radius: 3px;
font-size: 10px;
font-weight: 600;
}
.log-item.emit .log-type {
background: #dbeafe;
color: #1d4ed8;
}
.log-item.receive .log-type {
background: #bbf7d0;
color: #15803d;
}
.log-from,
.log-to {
color: var(--vp-c-text-2);
}
.log-arrow {
color: var(--vp-c-divider);
}
.log-data {
color: var(--vp-c-brand);
max-width: 200px;
overflow: hidden;
text-overflow: ellipsis;
white-space: nowrap;
}
.memory-warning {
margin-top: 20px;
padding: 16px;
background: #fffbeb;
border: 1px solid #fcd34d;
border-radius: 8px;
display: flex;
gap: 12px;
}
.warning-icon {
font-size: 24px;
flex-shrink: 0;
}
.warning-content h6 {
margin: 0 0 4px 0;
color: #92400e;
font-size: 14px;
}
.warning-content p {
margin: 0 0 8px 0;
color: #a16207;
font-size: 13px;
line-height: 1.5;
}
.warning-content pre {
margin: 0;
padding: 12px;
background: #fef3c7;
border-radius: 4px;
font-size: 12px;
overflow-x: auto;
}
.warning-content code {
color: #92400e;
font-family: monospace;
}
</style>