Vue 3.0 自定义 Composition API 管理状态
自定义 Composition API 用于管理状态,先明确一个思路,Composition API 封装的是将视图与状态解耦,所以状态解耦是我们封装的第一目标,首先我们需要分析有哪些必要状态、有哪些必要处理函数,进而在组件中使用即可。
在 Vue 3 中,自定义 Composition API 通过组合函数来封装逻辑,提供了一种更灵活和可重用的方式来管理组件状态。
下面是两个详细的例子,分别展示了如何封装拖拽逻辑和动画逻辑。
1. 封装拖拽逻辑 useDrag
1.1. 创建组件useDrag
import { ref, onMounted, onUnmounted } from 'vue';export function useDrag() {const position = ref({ x: 0, y: 0 });const isDragging = ref(false);const onMouseDown = (event) => {isDragging.value = true;position.value = { x: event.clientX, y: event.clientY };}const onMouseMove = (event) => {if (isDragging.value) {const deltaX = event.clientX - position.value.x;const deltaY = event.clientY - position.value.y;position.value = { x: event.clientX, y: event.clientY };document.documentElement.style.setProperty('--drag-x', ~$(deltaX)px');document.documentElement.style.setProperty('--drag-y', ~$(deltaY)px');}};const onMouseUp = () => {isDragging.value = false;};onMounted(() => {window.addEventListener('mousemove', onMouseMove);window.addEventListener('mouseup', onMouseUp);});onUnmounted(() => {window.removeEventListener('mousemove', onMouseMove);window.removeEventListener('mouseup', onMouseUp);});return {position,onMouseDown};
}
1.2. 使用组件useDrag
<template><div class="draggable" @mousedown="onMousedown">Drag me!</div>
</template><script>
import { useDrag } from './useDrag';export default {setup() {const { onMouseDown } = useDrag();return {onMousedown: onMouseDown};}
};
</script><style>
.draggable {position: absolute;top: calc(50% + var(--drag-y, 0px));left: calc(50% + var(--drag-x, 0px));transform: translate(-50%, -50%);background-color: lightblue;padding: 20px;cursor: grab;
}
</style>
1.3. useDrag总结
1. 状态管理:position 用于跟踪拖拽元素的位置,isDragging 用于指示是否正在拖拽;
2. 事件处理:
(1). onMouseDown:记录初始化位置并设置拖拽状态;
(2). onMouseMove:根据鼠标移动更新位置,并通过 CSS 变量更新元素位置;
(3). onMouseUp:结束拖拽;
3. 生命周期管理:在组件挂载和卸载时分别添加和移除事件监听器;
2. 封装动画逻辑useAnimation
2.1. 创建组件useAnimation
import { ref, onMounted, onUnmounted } from 'vue';export function useAnimation(animationName, duration) {const isAnimating = ref(false);const startAnimation = () => {isAnimating.value = true;setTimeout(() => {isAnimating.value = false;}, duration);};return {isAnimating,startAnimation};
}
2.2. 使用组件useAnimation
<template><div :class="{ animated: isAnimating }" @click="startAnimation">Click me to animate!</div>
</template><script>
import { useAnimation } from './useAnimation';export default {setup() {const { isAnimating, startAnimation } = useAnimation('fade', 1000);return {isAnimating,startAnimation};}
};
</script><style>
.animated {animation: fade 1s;
}@keyframes fade {0% { opacity: 0; }100% { opacity: 1; }
}
</style>
2.3. useAnimation总结
1. 状态管理:isAnimating 用于指示动画状态;
2. 动画控制:startAnimation 函数用于触发动画,并在动画结束后重置状态;