原文地址:http://www.cnblogs.com/flykai/p/3361064.html
前言
konckout.js本人也是刚刚接触,也是初学,本文的目的是使用ko和asp.net mvc4 webapi来实现一个简单增删改查操作。Knockout是一个以数据模型(data model)为基础的能够帮助你创建富文本,响应显示和编辑用户界面的JavaScript类库。任何时候如果你的UI需要自动更新(比如:更新依赖于用户的行为或者外部数据源的改变),KO能够很简单的帮你实现并且很容易维护。其作用简单来说就是声明所需的数据作为一个JavaScript 模型对象(model object),然后将DOM 元素或者模板(templates)绑定到它上面。
创建mvc4+webapi+konckout.js的简单应用程序
1、首先准备一个测试的数据库,我这以我随便创建的一个数据库为例
表结构如下图:
2、创建一个mvc程序,并在项目中添加一个以上表的ado.net实体数据模型
添加完成以后:
3、添加添加一个带读写操作的EmployeeApiController webapi控制器和用来实现增删改查的普通控制器EmployeeController
添加是注意选择是带读写操作的webapi控制器,选择好数据模型及数据库上下文,方面vs自动为我们生成读写操作。
添加完成后自动生成的完整代码:
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web;
using System.Web.Http;
using Knockout.Models; namespace Knockout.Controllers
{
public class EmployeeApiController : ApiController
{
private DemoDBEntities db = new DemoDBEntities(); // GET api/EmployeeApi
public IEnumerable<Employees> GetEmployees()
{
return db.Employees.AsEnumerable();
} // GET api/EmployeeApi/5
public Employees GetEmployees(int id)
{
Employees employees = db.Employees.Find(id);
if (employees == null)
{
throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound));
} return employees;
} // PUT api/EmployeeApi/5
public HttpResponseMessage PutEmployees(int id, Employees employees)
{
if (ModelState.IsValid && id == employees.EmployeeID)
{
db.Entry(employees).State = EntityState.Modified; try
{
db.SaveChanges();
}
catch (DbUpdateConcurrencyException)
{
return Request.CreateResponse(HttpStatusCode.NotFound);
} return Request.CreateResponse(HttpStatusCode.OK);
}
else
{
return Request.CreateResponse(HttpStatusCode.BadRequest);
}
} // POST api/EmployeeApi
public HttpResponseMessage PostEmployees(Employees employees)
{
if (ModelState.IsValid)
{
db.Employees.Add(employees);
db.SaveChanges(); HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.Created, employees);
response.Headers.Location = new Uri(Url.Link("DefaultApi", new { id = employees.EmployeeID }));
return response;
}
else
{
return Request.CreateResponse(HttpStatusCode.BadRequest);
}
} // DELETE api/EmployeeApi/5
public HttpResponseMessage DeleteEmployees(int id)
{
Employees employees = db.Employees.Find(id);
if (employees == null)
{
return Request.CreateResponse(HttpStatusCode.NotFound);
} db.Employees.Remove(employees); try
{
db.SaveChanges();
}
catch (DbUpdateConcurrencyException)
{
return Request.CreateResponse(HttpStatusCode.NotFound);
} return Request.CreateResponse(HttpStatusCode.OK, employees);
} protected override void Dispose(bool disposing)
{
db.Dispose();
base.Dispose(disposing);
}
}
}
在添加一个普通的控制器EmployeeController,并在里面添加如下方法:
public ActionResult Create()
{
return View("Create");
}
添加视图Create.cshtml:
首先在视图中添加对ko的引用,mapping.js是用来实现绑定viewmodel的第三方插件:
<script src="~/Scripts/knockout-2.1.0.js"></script>
<script src="~/Scripts/knockout.mapping-latest.js"></script>
在body节点下添加一个form表单如下代码:
<form>
<table>
<tr>
<td>
<!--将textbox监控属性的值与ViewModel绑定 -->
<table id="tbldml">
<tr>
<td>编号</td>
<td>
<input type="text" id="txteno" data-bind="value: $root.EmployeeID" disabled="disabled" /></td>
</tr>
<tr>
<td>名称</td>
<td>
<input type="text" id="txtename" data-bind="value: $root.EmployeeName" /></td>
</tr>
<tr>
<td>薪资</td>
<td>
<input type="text" id="txtsal" data-bind="value: $root.Salary" /></td>
</tr>
<tr>
<td>部门</td>
<td>
<input type="text" id="txtdname" data-bind="value: $root.DeptName" /></td>
</tr>
<tr>
<td>籍贯</td>
<td>
<input type="text" id="txtdesig" data-bind="value: $root.Address" /></td>
</tr>
<tr>
<!--ko控制的保存和修改按钮-->
<td>
<button data-bind="click :$root.save">保存</button></td>
<td>
<button data-bind="click: $root.update">修改</button></td>
</tr>
</table>
</td>
<td>
<div class="FixedContainer">
<!--控制有数据的时候显示表格-->
<table data-bind="visible: Employees().length>0">
<thead>
<tr>
<td>编号</td>
<td>名称</td>
<td>薪资</td>
<td>部门</td>
<td>籍贯</td>
<td></td>
</tr>
</thead>
<!--遍历所有数据->
<tbody data-bind="foreach: Employees">
<tr style="border: solid" data-bind="click: $root.getselectedemployee" id="updtr">
<td><span data-bind="text: EmployeeID"></span></td>
<td><span data-bind="text: EmployeeName"></span></td>
<td><span data-bind="text: Salary"></span></td>
<td><span data-bind="text: DeptName"></span></td>
<td><span data-bind="text: Address"></span></td>
<td>
<button data-bind="click: $root.deleterec">Delete</button></td>
</tr>
</tbody>
</table>
</div>
</td>
</tr>
</table> </form>
4、页面改造好以后,编写Ko需要的js来实现增删改查
在页面添加scripts占位节点添加如下脚本:
@section scripts{
<script type="text/javascript">
var EmpViewModel = function () {
var self = this; self.EmployeeID = ko.observable("0");
self.EmployeeName = ko.observable("");
self.Salary = ko.observable("");
self.DeptName = ko.observable("");
self.Address = ko.observable(""); var EmpData = {
EmployeeID: self.EmployeeID,
EmployeeName: self.EmployeeName,
Salary: self.Salary,
DeptName: self.DeptName,
Address: self.Address
}; //生命一个ObservableArray来存储返回的所有数据
self.Employees = ko.observableArray([]); GetEmployees(); //通过ajax请求返回所有数据
//保存数据
self.save = function () {
//Ajax 提交到webapi保存数据
alert(11);
$.ajax({
type: "POST",
url: "/api/EmployeeApi",
data: ko.toJSON(EmpData),
contentType: "application/json",
success: function (data) {
alert("记录保存成功");
self.EmployeeID(data.EmployeeID);
alert("新数据Id :" + self.EmployeeID());
GetEmployees();
},
error: function () {
alert("提交失败");
}
});
}; self.update = function () {
var url = "/api/EmployeeApi/" + self.EmployeeID();
alert(url);
$.ajax({
type: "PUT",
url: url,
data: ko.toJSON(EmpData),
contentType: "application/json",
success: function (data) {
alert("修改成功");
GetEmployees();
},
error: function (error) {
alert(error.status + "<!----!>" + error.statusText);
}
});
}; //删除操作
self.deleterec = function (employee) {
$.ajax({
type: "DELETE",
url: "/api/EmployeeApi/" + employee.EmployeeID,
success: function (data) {
alert("Record Deleted Successfully");
GetEmployees();//Refresh the Table
},
error: function (error) {
alert(error.status + "<--and--> " + error.statusText);
}
});
}; //获取所有Employee
function GetEmployees() {
//Ajax 获取所有Employee记录
$.ajax({
type: "GET",
url: "/api/EmployeeApi",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (data) {
self.Employees(data);
},
error: function (error) {
alert(error.status + "<--and--> " + error.statusText);
}
});
}
//点击右侧列表某一行左侧编辑赋值
self.getselectedemployee = function (employee) {
self.EmployeeID(employee.EmployeeID),
self.EmployeeName(employee.EmployeeName),
self.Salary(employee.Salary),
self.DeptName(employee.DeptName),
self.Address(employee.Address)
}; };
//激活knockout
ko.applyBindings(new EmpViewModel());
</script> }
代码中有比较详细的注释,其中实现的增删查改的操作是通过ajax异步调用webapi来实现的,刷新及数据绑定是通过ko来实现的。
5、运行程序得到如下效果:
新增记录的时候id默认为0,表单数据为空,点击保存实现无刷新保存,右侧若无数据表格则隐藏,若有数据表格显示数据列表。
点击某一行数据,左侧表单显示该行数据信息,并可以修改信息
点击删除实现无刷新删除数据记录。