拖拽上传图片(可多张)

左手的ㄟ右手 2022-06-03 10:36 283阅读 0赞

upload.html:

<!DOCTYPE html>
    <html lang="en">
    <head>
    	<meta charset="UTF-8">
    	<title>Document</title>
    	<style>
    		a{
    			cursor: pointer;
    		}
    		.d1{
    			width: 80%;
    			height: 200px;
    			background: #ddd;
    		}
    		.d2{
    			display: none;
    		}
    		#d1_content{
    			width: 75%;
    			height: 200px;
    		}
    		#a_upload{
    
    		}
    		img{
    			height: 50px;
    			margin-right: 20px;
    		}
    	</style>
    </head>
    <body>
    	<div class="d1">
    		<div id="d1_content"></div>
    	</div>
    	<div class="d2">
    		<input type="file" name="mypic" style="display:none;">
    	</div>
    	
    	<a id="a_upload">上传</a>
    	
    	<script src="js/jquery.min.js"></script>
    	<script src="js/ajax.js"></script>
    	<script>
    		//拖动上传图片
    		function getId(id){
    			return document.getElementById(id);
    		}
    		$(document).on({
    			dragenter:function(e){e.preventDefault()},
    			dragover:function(e){e.preventDefault()},
    			dragleave:function(e){e.preventDefault()},
    			drop:function(e){e.preventDefault()},
    		});
    		var drop_area=getId("d1_content");
    		//ondrop 事件在可拖动元素或选取的文本放置在目标区域时触发。
    		var fd=null,fd1=null,fd2=null,fd3=null,fd4=null;
    		var count=0;
    		drop_area.οndrοp=function(e){
    			e.preventDefault();
    			var fileInfo=e.dataTransfer.files;       
    
    			var size=Math.ceil(fileInfo[0].size/1024);
    			if(size>2048){
    				alert("上传图片太大，不能超过2MB");
    				return;
    			}
    
    			var type=fileInfo[0].type.indexOf("image");
    			if(type==-1){
    				alert("只能上传图片格式的文件");
    				return;
    			}
    
    			var img=window.URL.createObjectURL(fileInfo[0]);
    			var html=`<img src="${img}" />`;
    			var his_html=$("#d1_content").html();
    			$("#d1_content").html(his_html+html);
    			switch(count){
    				case 0:
    					fd=new FormData();
    					//这里fd会缓存图片相关信息
    					fd.append("mypic",fileInfo[0]);
    					break;
    				case 1:
    					fd1=new FormData();
    					fd1.append("mypic",fileInfo[0]);
    					break;
    				case 2:
    					fd2=new FormData();
    					fd2.append("mypic",fileInfo[0]);
    					break;
    				case 3:
    					fd3=new FormData();
    					fd3.append("mypic",fileInfo[0]);
    					break;
    				case 4:
    					fd4=new FormData();
    					fd4.append("mypic",fileInfo[0]);
    					break;
    			}
    			++count;
    		}
    
    		a_upload.οnclick=function(e){
    			e.preventDefault();
    			for(var i=0;i<count;i++){
    				var xhr = new XMLHttpRequest();
    			    xhr.onreadystatechange = function(){
    			      console.log(xhr.responseText);
    			    }
    			    xhr.open("POST","upload.php",true);
    			    xhr.setRequestHeader("X-Requested-With",
    			      "XMLHttpRequest");
    			    switch(i){
    					case 0:
    						xhr.send(fd);
    						break;
    					case 1:
    						xhr.send(fd1);
    						break;
    					case 2:
    						xhr.send(fd2);
    						break;
    					case 3:
    						xhr.send(fd3);
    						break;
    					case 4:
    						xhr.send(fd4);
    						break;
    				}
    			}
    		}
    	</script>
    </body>
    </html>

注：需要引入JQ。

ajax.js:

//封装适合各种情况的简化版ajax函数
    function ajax({//利用解构，获取将来参数对象中每个属性值
      type,//请求类型: "get"||"post"
      url,//请求的url地址: "xxx.php"
      data,//请求携带的参数: "变量1=值&..."
      dataType,//服务器端返回值类型: "json"||"text"
    }){
      //服务器端返回值类型默认为text
      dataType=dataType||"text";
      //只要远程请求，必有延迟，只要延迟，比用promise等待完成后，才执行后续操作
      return new Promise(function(resolve){//.then()
        //AJAX 4步/5步:
        var xhr=new XMLHttpRequest();//1.获得xhr对象
        //如果是get请求，且传入了data参数，才需要拼接url和data为get请求的完整地址
        if(type.toLowerCase()=="get"&&data!==undefined)
          url+="?"+data;
        xhr.open(type,url,true);//2. 建立连接
        //3. 设置请求状态回调函数
        xhr.onreadystatechange=function(){
          //如果请求完成，且成功!
          if(xhr.readyState==4&&xhr.status==200){
            //如果服务器端响应类型不是json，则调用后续resolve操作，并传入原始responseText，做后续处理
            if(dataType.toLowerCase()!="json")
              resolve(xhr.responseText);
            else//如果服务器端响应类型是json，则自动调用JSON.parse转为js对象，再交给resolve函数做后续处理
              resolve(JSON.parse(xhr.responseText));
          }
        }
        //只有type为post，才需要设置请求头
        if(type.toLowerCase()=="post")
          xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
        //只有type为post，才需要send时，传入参数
        xhr.send(type.toLowerCase()=="post"?data:null);
      })
    }

init.php:

<?php 
    
    	$conn=mysqli_connect('127.0.0.1','root','','upload',3306);      
    	mysqli_query($conn,"SET NAMES UTF8");
    ?>

upload.php:

<?php 
    
    	require("init.php");
    
    	$rs=empty($_FILES);
    	if($rs){
    		echo '{"code":-1,"msg":"没有上传文件"}';
    		exit;
    	}
    
    	$picname=$_FILES["mypic"]["name"];
    	$picsize=$_FILES["mypic"]["size"]/1000;
    	$type=strtolower(strstr($picname,"."));
    	if($type!=".jpg"&&$type!=".gif"&&$type!=".png"){
    		echo '{"code":-2,"msg":"上传文件类型错误"}';
    		exit;
    	}
    	if($picsize>2048){
    		echo '{"code":-3,"msg":"上传文件过大，不能超过2MB"}';
    		exit;
    	}
    
    	$filename=time().rand(1,9999).$type;
    	$src=$_FILES["mypic"]["tmp_name"];
    	$des="uploads/".$filename;
    	move_uploaded_file($src,$des);
    
    	$sql="INSERT INTO upload_img(path) VALUES('$des')";
    	$result=mysqli_query($conn,$sql);
    	if($result)
    		echo '{"code":1,"msg":"上传成功"}';
    ?>

效果图：

![20171226154335395][]

upload.html精简代码后：

<!DOCTYPE html>
    <html lang="en">
    <head>
    	<meta charset="UTF-8">
    	<title>Document</title>
    	<style>
    		a{
    			cursor: pointer;
    		}
    		.d1{
    			width: 80%;
    			height: 200px;
    			background: #ddd;
    		}
    		.d2{
    			display: none;
    		}
    		#d1_content{
    			width: 75%;
    			height: 200px;
    		}
    		#a_upload{
    
    		}
    		img{
    			height: 50px;
    			margin-right: 20px;
    		}
    	</style>
    </head>
    <body>
    	<div class="d1">
    		<div id="d1_content"></div>
    	</div>
    	<div class="d2">
    		<input type="file" name="mypic" style="display:none;">
    	</div>
    	
    	<a id="a_upload">上传</a>
    	
    	<script src="js/jquery.min.js"></script>
    	<script src="js/ajax.js"></script>
    	<script>
    		//拖动上传图片
    		function getId(id){
    			return document.getElementById(id);
    		}
    		//避免其他操作的默认事件对效果产生影响
    		$(document).on({
    			dragenter:function(e){e.preventDefault()},
    			dragover:function(e){e.preventDefault()},
    			dragleave:function(e){e.preventDefault()},
    			drop:function(e){e.preventDefault()},
    		});
    		var drop_area=getId("d1_content");
    		//ondrop 事件在可拖动元素或选取的文本放置在目标区域时触发。
    		var fd0=null,fd1=null,fd2=null,fd3=null,fd4=null;
    		var count=0;
    		drop_area.οndrοp=function(e){
    			e.preventDefault();
    			var fileInfo=e.dataTransfer.files;       
    			var size=Math.ceil(fileInfo[0].size/1024);
    			console.log("文件大小："+size);
    			if(size>2048){
    				alert("上传图片太大，不能超过2MB");
    				return;
    			}
    			var type=fileInfo[0].type.indexOf("image");
    			if(type==-1){
    				alert("只能上传图片格式的文件");
    				return;
    			}
    			var img=window.URL.createObjectURL(fileInfo[0]);
    			var html=`<img src="${img}" />`;
    			var his_html=$("#d1_content").html();
    			$("#d1_content").html(his_html+html);
    			fd_name = "fd"+count;
    			window[fd_name]=new FormData();
    			window[fd_name].append("mypic",fileInfo[0]);
    			++count;
    		}
    
    		a_upload.οnclick=function(e){
    			e.preventDefault();
    			for(var i=0;i<count;i++){
    				var xhr = new XMLHttpRequest();
    			    xhr.onreadystatechange = function(){
    			      console.log(xhr.responseText);
    			    }
    			    xhr.open("POST","upload.php",true);
    			    xhr.setRequestHeader("X-Requested-With",
    			      "XMLHttpRequest");
    			    fd_name = "fd"+i;
    			    xhr.send(window[fd_name]);
    			}
    		}
    	</script>
    </body>
    </html>

主要是去掉了switch，用其他方式实现。

[20171226154335395]: /images/20220603/480a43e9e8854b10afed52f6a79f392f.png