I mainly want to store the returned information in data when post returns, and find that it is not possible for setData to be written in wx.request. Finally, I can only use wx.setStorageSync storage. I just contacted Mini Program and soon wanted to ask the boss if there is any other way to save the return value.

var that=this;
Page({
  data: {
    mediaurl:"1"
  },
onLaunch: function() {
    var that = this;
    wx.request({
      url: "http://www.test.php/login",
      data: {
        UserCode: "wechart",
      },
      method: "post",
      success: function (res) {
        that.setData({
          mediaurl: ""
        })
      }
    })
    }
})