项目前的知识点准备（2）

#region 查
/// <summary>
/// 查
/// </summary>
/// <returns></returns>
public ActionResult Index()
{
    var models = from m in db.Provinces select m;
    return View(models.ToList());
}
#endregion

#region 增
/// <summary>
/// 增
/// </summary>
/// <returns></returns>
public ActionResult Create()
{
    return View();
}
/// <summary>
/// 接收创建页面的数据并存储
/// </summary>
/// <param name="model"></param>
/// <returns></returns>
[HttpPost]
public ActionResult Create(Province model)
{
    //
    if (ModelState.IsValid)
    {
        db.Provinces.Add(model);//添加
        db.SaveChanges();//提交至数据库
        return RedirectToAction("Index");
    }
    return View(model);
}
#endregion

#region 删
 /// <summary>
/// 删
/// </summary>
/// <param name="id"></param>
/// <returns></returns>
public ActionResult Delete(int id)
{
    var model = db.Provinces.Find(id);
    if (model == null)
    {
        return RedirectToAction("Index");
    }
    return View(model);
}
/// <summary>
/// 删除,签名一致方法的处理
/// </summary>
/// <param name="id"></param>
/// <param name="collection"></param>
/// <returns></returns>
[HttpPost]
public ActionResult Delete(int id, FormCollection collection)
{
    var model = db.Provinces.Find(id);
    if (model != null)
    {
        db.Provinces.Remove(model);
        db.SaveChanges();
    }
    return RedirectToAction("Index");
}
#endregion

#region 改
/// <summary>
/// 改
/// </summary>
/// <param name="id"></param>
/// <returns></returns>
public ActionResult Edit(int id)
{
    var model = db.Provinces.Find(id);
    //如果为空，直接重定向到index
    if (model == null) return RedirectToAction("Index");
    return View(model);
}
/// <summary>
/// 接收修改页面的数据并存储
/// </summary>
/// <param name="model"></param>
/// <returns></returns>
[HttpPost]
public ActionResult Edit(Province model)
{
    if (ModelState.IsValid)
    {
        //把存储状态修改成“Modified”
        db.Entry(model).State = System.Data.EntityState.Modified;
        db.SaveChanges();
        return RedirectToAction("Index");
    }
    return View(model);
}
#endregion