Asp.Net Mvc中的一些初级问题整理
1.如何让Controller不返回视图？(比如仅执行一些数据库操作)
很简单，只要在Controller中定义一个void类型的public方法即可
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public void DeleteData() |
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{ |
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using (SQLiteConnection conn = new SQLiteConnection("Data Source=" + Server.MapPath(_dbFile))) |
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{ |
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conn.Open(); |
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SQLiteCommand cmd = conn.CreateCommand(); |
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cmd.CommandText = "delete from Products"; |
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cmd.ExecuteNonQuery(); |
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} |
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|
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//顺便给个sqlite使用事务的代码 |
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//using (SQLiteConnection conn = new SQLiteConnection("Data Source=" + Server.MapPath(_dbFile))) |
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//{ |
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//conn.Open(); |
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//SQLiteTransaction t = conn.BeginTransaction(); |
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//try |
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//{ |
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//SQLiteCommand cmd = conn.CreateCommand(); |
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//cmd.CommandText = "insert into Products(Name,CreateDate,UpdateDate) values(@Name,@CreateDate,@UpdateDate)"; |
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|
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//for (int i = 0; i < 50; i++) |
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//{ |
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//cmd.Parameters.Clear(); |
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//cmd.Parameters.AddWithValue("Name", i.ToString().PadLeft(5, '0')); |
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//cmd.Parameters.AddWithValue("CreateDate", DateTime.Now); |
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//cmd.Parameters.AddWithValue("UpdateDate", DateTime.Now); |
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//cmd.ExecuteNonQuery(); |
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//} |
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|
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//t.Commit(); |
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//} |
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//catch |
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//{ |
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//t.Rollback(); |
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//} |
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//} |
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} |
这样就行了，调用方法类似 : http://localhost/Product/DeleteData 即可
2.如何让视图返回纯文本或Xml?
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public ActionResult GetTxt() |
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{ |
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return new ContentResult() { ContentType = "text/plain", ContentEncoding = Encoding.UTF8, Content = "Hello World!" }; |
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} |
如果要返回xml,把text/plain改为text/xml即可.
3.如何把DataTable传给视图?
虽然很多官方教程都是推荐使用强类型的视图，但是需求是千变万化的，如果确实要传递DataTable给视图，可参考下面这个做:
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public ActionResult Index() |
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{ |
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DataTable tbl = new DataTable(); |
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using (SQLiteConnection conn = new SQLiteConnection("Data Source=" + Server.MapPath(_dbFile))) |
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{ |
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SQLiteDataAdapter da = new SQLiteDataAdapter("Select * from Products", conn); |
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da.Fill(tbl); |
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ViewData["data"] = tbl; |
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} |
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return View(); |
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} |
然后在视图上可以这样写：
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<% |
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DataTable tbl = ViewData["data"] as DataTable; |
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foreach (DataRow dr in tbl.Rows) |
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{ |
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//... |
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} |
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%> |
4.如何使用自定义控件(做为数据显示模板)?
创建一个Partial View（局部视图），内容可参考这样:
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<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %> |
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<%@ Import Namespace="System.Data" %> |
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<tr> |
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<td> |
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<%=(ViewData.Model as DataRow)["Id"] %> |
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</td> |
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<td> |
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<%=(ViewData.Model as DataRow)["Name"]%> |
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</td> |
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<td> |
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<%=(ViewData.Model as DataRow)["CreateDate"]%> |
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</td> |
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<td> |
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<%=(ViewData.Model as DataRow)["UpdateDate"]%> |
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</td> |
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</tr> |
然后在主视图中可这样使用:
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<table> |
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<tr> |
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<th> |
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Id |
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</th> |
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<th> |
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Name |
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</th> |
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<th> |
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CreateDate |
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</th> |
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<th> |
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UpdateDate |
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</th> |
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</tr> |
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<% |
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DataTable tbl = ViewData["data"] as DataTable; |
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foreach (DataRow dr in tbl.Rows) |
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{ |
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Html.RenderPartial("~/Views/Product/ProductData.ascx", dr); |
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} |
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%> |
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</table> |
5.页面/视图之间如何跳转？
分二种情况：
void类型的action(即问题1中所说的不返回视图的action):
有且只有一种方法：
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Response.Redirect("/product/Index"); |
注意：
如果写成Redirect("/product/Index"); 编译也会通过，但是根本不会有效果，因为前面不加Response.则变成了Controller类的Redirect方法，这个是有返回值的，必须用return Redirect()调用才会有效果，但是该方法又是void类型的，不允许return，所以才说这是有且仅有的一种方法.
常规返回ActionResult的action:
方法就很多了:
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public ActionResult ShowView1() |
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{ |
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Response.Redirect("ShowView2"); //方法1 |
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//return Redirect("ShowView2"); //方法2 |
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//return RedirectToAction("ShowView2"); //方法3 |
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return View("ShowView2"); //方法4 |
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} |
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|
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public ActionResult ShowView2() |
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{ |
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ViewData["data"] = "View2"; |
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return View(); |
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} |
