JavaScript图片上传并预览
哪 吒 人气:0一、前端界面是通过jqgrid展示的
jqgrid是典型的B／C架构（浏览器／服务器模式），服务器端只需提供数据管理，浏览器只需负责数据显示。
jqGrid是用ajax实现对请求和响应的处理，支持局部实时刷新。
二、jqgrid特性
- 通过配置url地址数据显示格式
- 支持行编辑，列搜索过滤
- 支持分页
- 添加表单支持文件上传
- 链式调用
三、代码实例
1、jqgrid页面展示
$(document).ready(function () {
$("#gridTable").jqGrid({
colNames:['标号','班次', '第一班', '第二班', '第三班', '第四班','操作'],
colModel:[{
name:'mark',
index:'mark',
width: 100,
},{
name:'division',
index:'division',
width: 100,
},{
name:'first_class',
index:'first_class',
width: 100,
}, {
name:'second_class',
index:'second_class',
width: 100,
},{
name:'third_class',
index:'third_class',
width: 100,
}, {
name: 'fouth_class',
index: 'fouth_class',
width: 100,
}, {
name: 'operate',
index: 'operate',
width: 200,
search: false,
formatter : function(cellvalue,options,rowObject){
var id = rowObject.mark
var str = '<button class="btn-info" data-for="pictureModal">'+
'图片'+
'</button>';
return str;
},
}
],
sortname : "mark",
sortorder : "desc",
viewrecords : true,
width: 747,
height: 355,
rowNum: 10,
datatype: 'text',
pager: "#gridPager",
onSelectRow:function(rowid){
grid_selectRow = $("#gridTable").jqGrid("getRowData",rowid);
$("#modal_picture").pictureLoading({});
},
ondblClickRow: function(rowid) {
grid_selectRow = $("#gridTable").jqGrid("getRowData",rowid);
$("#edit").trigger("click");
},
});
jf_initJqgrid();
jf_click();
function jf_initJqgrid(){
$.ajax({
url:"DivisiondefineServlet",
async:true, //是否为异步请求
cache:false, //是否缓存结果
type:"GET",
dataType:"json",
success : function(data){
$("#gridTable").jqGrid("clearGridData");
for(var i=0;i<=data.length;i++){
$("#gridTable").jqGrid('addRowData',i+1,data[i]);
}
}
})
}
$('[id^=jqgh_gridTable_]').css("height","20px");
function jf_click() {
$("#add").click(function () {
$("#modal-divisionAdd").divisionAdd({});
})
$("#edit").click(function () {
$("#modal-divisionEdit").divisionEdit({});
})
$("#delete").click(function () {
jf_delete();
jf_initJqgrid();
})
}
function jf_delete() {
$.ajax({
url:"DivisiondefineServlet?action=delete",
async:true, //是否为异步请求
cache:false, //是否缓存结果
type:"POST",
dataType:"text",
data :{
"mark1" : grid_selectRow.mark,
},
})
}
});2、模块页面
;(function($){
$.fn.pictureLoading = function(options){
var el = this;
var opts = {
}
var param = $.extend(opts,options);
var or = new Order(el, param);
}
var Order = function(el,param){
this.el=el;
this.param=param;
this.orderContent();
this.bindEvent();
this.orderSetValue();
}
Order.prototype = {
orderContent : function(){
//创建模态窗体
this.el.addClass("modal").attr("tabindex","-1").attr("data-backdrop","static");
html= '<div class="modal-dialog">'+
'<div class="modal-content" style="width: 450px">'+
'<div class="modal-header" style="border-bottom:0px;">'+
'<div class="row col-sm-12">'+
'<div class="col-sm-8" align="left">'+
'<span></span>'+
'</div>'+
'<div class="col-sm-4" align="right">'+
'<button class="close" data-dismiss="modal" aria-hidden="true" value="HTML">'+
'<span class="blue">×</span>'+
'</button>'+
'</div>'+
'</div>'+
'</div>'+
'<div class="modal-body" style="height:350px;top: -30px">'+
'<form id="form" action="PictureServlet" method="post">'+
'<span>标号</span><input id="mark" name="mark" disabled/>'+
'<span id="FPicName">'+
'<input id="IronMan" type="file" size="45" name="IronMan" class="avatar input" οnchange="loadfile(); "style="display:none";/>'+
'<img id="viewImg" class="viewImg" src="picture/html.jpg" style="height: 300px;width: 400px;" ="loadPic();" >'+
'</span>'+
'</form>'+
'</div>'+
'<div class="modal-footer">'+
'<div align="right">'+
'<div class="btn-group">'+
'<button id="btnSubCancel" class="btn btn-default btn-sm" data-dismiss="modal">'+
'<span>退出</span>'+
'</button>'+
'</div>'+
'</div>'+
'</div>'+
'</div>'+
'</div>';
this.el.html("");
this.el.append(html);
this.el.modal("show");
},
orderSetValue : function(){
$("#mark").val(grid_selectRow.mark);
$.ajax({
url:"PictureServlet",
async:true, //是否为异步请求
cache:false, //是否缓存结果
type:"GET",
dataType:"json",
data :{
"mark" : $("#mark").val()
},
success : function(data){
$('#viewImg').attr('src', "../../../picture/" + data);
},
error:function () {
alert("error");
}
})
},
//自定义JS点击事件
bindEvent : function(){
},
}
})(jQuery)3、ajax实现异步请求
function loadfile(){
var picName = $("#IronMan").val().replace("C:\fakepath\","");
$.ajax({
url:"PictureServlet",
async:true, //是否为异步请求
cache:false, //是否缓存结果
type:"POST",
dataType:"json",
data :{
"mark" : $("#mark").val(),
"picName":picName,
},
})
$('#viewImg').attr('src', "../../../picture/" + picName);
}
4、servlet存储并在本地存储图片文件
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
System.out.println("servlet");
response.setContentType("text/html");
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
int mark = Integer.parseInt(request.getParameter("mark"));
String picName = request.getParameter("picName");
service.insertPic(mark,picName);
String directory = "E:/GDKJ/others/imooc_pic";
File file = new File(directory,picName);
if(file.exists()) {
System.out.println(file.getAbsolutePath());
System.out.println(file.getName());
System.out.println(file.length());
} else {
file.getParentFile().mkdirs();
try {
file.createNewFile();
} catch (IOException e) {
System.out.println("创建新文件时出现了错误。。。");
e.printStackTrace();
}
}
}
五、效果展示
总结
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