小程序绘制多张网络图片

downfile:function(url){

  return new Promise(function(resolve,reject){

    wx.downloadFile({

      url:url,

      success:function(res){

        resolve(res.tempFilePath)

      }

    })

  })

var promise1 = that.downfile(“网络图片”);

    Promise.all([promise1]).then(res => {

      ctx.drawImage(res[0], 0, 0, 375,603);

  })