原生微信小程序 实现鼠标拖拽的按钮效果

业务中需要实现鼠标拖拽一个按钮的功能，避免遮住页面中的内容，效果如下

最终效果

于是就封装了这样一个组件

组件封装

1.html部分

<view class="gtn-container" bindtap="gotoForm" bindtouchstart="buttonStart" catchtouchmove="buttonMove"
    style="top:{{buttonTop}}px;left:{{buttonLeft}}px">
    
    <van-icon name="plus" color="#fff" size="46rpx" />
view>

2.css

.gtn-container {
  position: fixed;
  /* bottom: 200rpx;
    right: 60rpx; */
  width: 104rpx;
  height: 104rpx;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: #FFAA00;
  border-radius: 50%;
  z-index: 9999;
}

3.json部分

{
  "component": true,
  "usingComponents": {
    "van-icon": "@vant/weapp/icon/index"
  }
}

4.核心js

//const { getStorage, setStorage } = require('~/utils/auth')
const { checkToken } = require('~/utils/isLogin')
let startPoint = null
Component({
  /**
   * 组件的属性列表
   */
  properties: {

  },

  /**
   * 组件的初始数据
   */
  data: {
    buttonTop: 0,
    buttonLeft: 0,
    windowHeight: 0,
    windowWidth: 0
  },
  pageLifetimes: {
    show() {
      wx.getSystemInfo({
        success: (res) => {
          console.log(res, 'info')
          //获取到设备的宽高
          let h = res.windowHeight, w = res.windowWidth
          this.setData({
            windowHeight: h,
            windowWidth: w,
            /* buttonLeft: getStorage('buttonLeft') ? getStorage('buttonLeft') : w * 0.7,
            buttonTop: getStorage('buttonTop') ? getStorage('buttonTop') : h * 0.7 */
            buttonLeft: w * 0.7,
            buttonTop: h * 0.7
          })
        }
      })
    },
    hide: function () {
      // 页面被隐藏
      /*  setStorage('buttonLeft', this.data.buttonLeft)
       setStorage('buttonTop', this.data.buttonTop) */
    },
  },
  /**
   * 组件的方法列表
   */
  methods: {
    gotoForm() {
      checkToken(() => {
        wx.navigateTo({
          url: '/pages/form/index'
        })
      })
    },
    buttonStart(e) {
      console.log(e, 'buttonStart')
      startPoint = e.touches[0]
    },
    buttonMove(e) {
      //计算拖动后的坐标
      let endPoint = e.touches[e.touches.length - 1],
        disX = endPoint.clientX - startPoint.clientX,
        disY = endPoint.clientY - startPoint.clientY
      startPoint = endPoint

      let buttonTop = this.data.buttonTop + disY,
        buttonLeft = this.data.buttonLeft + disX

      //判断是否超出屏幕
      if (buttonLeft + 52 >= this.data.windowWidth) {
        buttonLeft = this.data.windowWidth - 52
      }
      if (buttonLeft <= 0) {
        buttonLeft = 0
      }
      if (buttonTop + 52 >= this.data.windowHeight) {
        buttonTop = this.data.windowHeight - 52
      }
      if (buttonTop <= 0) {
        buttonTop = 0
      }

      this.setData({
        buttonTop,
        buttonLeft
      })
      // console.log(disX, disY, '999')
    }
  }
})

最后在页面中引入使用

{
  "usingComponents": {
    "zp-button": "/components/round-button/index",
  },
  "navigationBarTitleText": "首页"
}

就可以实现在小程序页面拖拽一个按钮的功能