javascript实现移动端上传图片功能

window.onload = function() {
 let fileTag = document.getElementById('file');
 // console.log(fileTag)
 // console.log(this.pic)
 let that = this
 
 fileTag.onchange = function() {
 let file = fileTag.files[0];
 let fileReader = new FileReader();
 // console.log(file)
 console.log(fileReader)
 // console.log(that.pic)
 fileReader.onloadend = function() {
 console.log(1212)
 if (fileReader.readyState == fileReader.DONE) {
  // console.log(that.pic)
  console.log(fileReader)
  
  if(that.pic=="") {
  console.log(1111)
  that.pic = fileReader.result
  that.input1 = false
  
  that.upLoad(fileReader.result)
  return
  }else{
  if(that.pic2=='') {
  console.log(2222)
  that.pic2 = fileReader.result
  that.input2 = false
  return
  }else {
  if(that.pic3=='') {
  console.log(3333)
  that.pic3 = fileReader.result
  that.input3 = false
  return
  }else {
  if(that.pic4=='') {
   console.log(4444)
   that.pic4 = fileReader.result
   that.input4 = false
   return
  }else {
   console.log(5555)
   if(that.pic5=='') {
   that.pic5 = fileReader.result
   that.input5 = false
   return
   }
   
  }
  }
  }
  
  }
  // console.log(that.pic)
 }
 };
 
 fileReader.readAsDataURL(file);
 }
} 

<div class="imgBox" @click="upImg">
 <div style="display:flex;flex-flow:wrap;">
 <div class="Img" >
 <label>
 <img v-if="pic==''" src="./img/addPhotos.jpg">
 <img v-else width='100%' height='100%' style="border-radius:5px" id="img" :src="pic">
 <input v-if="input1" class="myInput" type="file" id="file" aept="image/*" multiple required>
 </label>
 <div v-if="pic!=''" class="myDel" @click="delImg(1)">X</div>
 
 </div>
 <div class="Img" v-if="pic!='' || !input2">
 <label>
 <img v-if="pic2==''" src="./img/addPhotos.jpg">
 <img v-else width='100%' height='100%' style="border-radius:5px" :src="pic2">
 <input v-if="input2" class="myInput" type="file" id="file" aept="image/*" multiple required>
 </label>
 <div v-if="pic2!=''" class="myDel" @click="delImg(2)">X</div>
 </div>
 <div class="Img" v-if="(pic!='' && pic2!='' ) || !input3">
 <label>
 <img v-if="pic3==''" src="./img/addPhotos.jpg">
 <img v-else width='100%' height='100%' style="border-radius:5px" :src="pic3">
 <input v-if="input3" class="myInput" type="file" id="file" aept="image/*" multiple required>
 </label>
 <div v-if="pic3!=''" class="myDel" @click="delImg(3)">X</div>
 </div>
 <div class="Img" v-if="(pic!='' && pic2!='' && pic3!='') || !input4">
 <label>
 <img v-if="pic4==''" src="./img/addPhotos.jpg">
 <img v-else width='100%' height='100%' style="border-radius:5px" :src="pic4">
 <input v-if="input4" class="myInput" type="file" id="file" aept="image/*" multiple required>
 </label>
 <div v-if="pic4!=''" class="myDel" @click="delImg(4)">X</div>
 </div>
 <div class="Img" v-if="(pic!='' && pic2!='' && pic3!='' && pic4!='') || !input5">
 <label> 
 <img v-if="pic5==''" src="./img/addPhotos.jpg">
 <img v-else width='100%' height='100%' style="border-radius:5px" :src="pic5">
 <input v-if="input5" class="myInput" type="file" id="file" aept="image/*" multiple required>
 </label>
 <div v-if="pic5!=''" class="myDel" @click="delImg(5)">X</div>
 </div>
 </div>
</div>

pic:'',
pic2:'',
pic3:'',
pic4:'',
pic5:'',
input1:true,
input2:true,
input3:true,
input4:true,
input5:true

upImg() {
 
 // window.onload = function() {
 let fileTag = document.getElementById('file');
 // console.log(fileTag)
 // console.log(this.pic)
 let that = this
 
 fileTag.onchange = function() {
 let file = fileTag.files[0];
 let fileReader = new FileReader();
 // console.log(file)
 console.log(fileReader)
 // console.log(that.pic)
 fileReader.onloadend = function() {
 console.log(1212)
 if (fileReader.readyState == fileReader.DONE) {
  // console.log(that.pic)
  console.log(fileReader)
  
  if(that.pic=="") {
  console.log(1111)
  that.pic = fileReader.result
  that.input1 = false
  
  that.upLoad(fileReader.result)
  return
  }else{
  if(that.pic2=='') {
  console.log(2222)
  that.pic2 = fileReader.result
  that.input2 = false
  return
  }else {
  if(that.pic3=='') {
  console.log(3333)
  that.pic3 = fileReader.result
  that.input3 = false
  return
  }else {
  if(that.pic4=='') {
   console.log(4444)
   that.pic4 = fileReader.result
   that.input4 = false
   return
  }else {
   console.log(5555)
   if(that.pic5=='') {
   that.pic5 = fileReader.result
   that.input5 = false
   return
   }
  }
  }
  }
  }
  // console.log(that.pic)
 }
 };
 fileReader.readAsDataURL(file);
 }
 // } 
},
delImg(num) {
 if(num==1) {
 this.pic = ''
 this.input1 = true
 }
 if(num==2) {
 this.pic2 = ''
 this.input2 = true
 }
 if(num==3) {
 this.pic3 = ''
 this.input3 = true
 }
 if(num==4) {
 this.pic4 = ''
 this.input4 = true
 }
 if(num==5) {
 this.pic5 = ''
 this.input5 = true
 }
}

#order .imgBox {
 margin-bottom: 100px;
 padding: 20px;
 box-sizing: border-box;
 background: #fff;
 height: 250px;
}

#order .Img {
 width: 90px;
 height: 90px;
 background: #fff;
 text-align: center;
 line-height: 132px;
 box-sizing: border-box;
 border-radius: 5px;
 border: 1px solid rgba(0,0,0,.2);
 position: relative;
 margin: 0 20px 20px 0;
}

#order .myInput {
 opacity:0;
 position:absolute;
 :0;
 :0;
 width:90px;
 height:90px;
 left:0;
}

#order .myDel {
 color: #fff;
 position: absolute;
 right: -10px;
 : -7px;
 width: 25px;
 height: 25px;
 border-radius: 25px;
 line-height: 25px;
 background: rgba(0,0,0,.5);
}