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ObjectDataSource.TypeName 屬性

  • 參考

定義

命名空間:
System.Web.UI.WebControls
組件:
System.Web.dll

取得或設定 ObjectDataSource 物件表示之類別的名稱。

public string TypeName { get; set; }

屬性值

String

部分或完整類別名稱 (Fully Qualified Class Name)，識別 ObjectDataSource 表示的物件型別。 預設為空字串 ("")。

範例

下列程式代碼範例示範控件如何使用 GridView Web Forms 頁面上的控件來顯示數據 ObjectDataSource 。 會 ObjectDataSource 使用其 TypeName 屬性識別部分或完整類別名稱，以及呼叫 以使用其 SelectMethod 屬性擷取數據的方法。 在運行時間，會建立 物件，並使用反映呼叫 方法。 控件 GridView 會透過 IEnumerable 屬性傳回的 SelectMethod 集合列舉，並顯示數據。

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS" Assembly="Samples.AspNet.CS" %>
<%@ Page language="c#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>ObjectDataSource - C# Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">

        <asp:gridview
          id="GridView1"
          runat="server"
          datasourceid="ObjectDataSource1" />

        <asp:objectdatasource
          id="ObjectDataSource1"
          runat="server"
          selectmethod="GetAllEmployees"
          typename="Samples.AspNet.CS.EmployeeLogic" />

    </form>
  </body>
</html>

下列範例顯示 屬性值所參考的 TypeName 類別。

namespace Samples.AspNet.CS {

using System;
using System.Collections;
using System.Collections.Specialized;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Web.UI;
using System.Web.UI.WebControls;
  //
  // EmployeeLogic is a stateless business object that encapsulates
  // the operations one can perform on a NorthwindEmployee object.
  //
  public class EmployeeLogic {

    // Returns a collection of NorthwindEmployee objects.
    public static ICollection GetAllEmployees () {
      ArrayList al = new ArrayList();

      ConnectionStringSettings cts = ConfigurationManager.ConnectionStrings["NorthwindConnection"];

      SqlDataSource sds
        = new SqlDataSource(cts.ConnectionString, "SELECT EmployeeID FROM Employees");

      try {

        IEnumerable IDs = sds.Select(DataSourceSelectArguments.Empty);

        // Iterate through the Enumeration and create a
        // NorthwindEmployee object for each ID.
        foreach (DataRowView row in IDs) {
          string id = row["EmployeeID"].ToString();
          NorthwindEmployee nwe = new NorthwindEmployee(id);
          // Add the NorthwindEmployee object to the collection.
          al.Add(nwe);
        }
      }
      finally {
        // If anything strange happens, clean up.
        sds.Dispose();
      }

      return al;
    }
    public static NorthwindEmployee GetEmployee(object anID) {
      return new NorthwindEmployee(anID);
    }

    public static void UpdateEmployeeInfo(NorthwindEmployee ne) {
      bool retval = ne.Save();
      if (!retval) { throw new NorthwindDataException("UpdateEmployee failed."); }
    }

    public static void DeleteEmployee(NorthwindEmployee ne) { }
  }

  public class NorthwindEmployee {

    public NorthwindEmployee () {
      ID = DBNull.Value;
      lastName = "";
      firstName = "";
      title="";
      titleOfCourtesy = "";
      reportsTo = -1;
    }

    public NorthwindEmployee (object anID) {
      this.ID = anID;

      ConnectionStringSettings cts = ConfigurationManager.ConnectionStrings["NorthwindConnection"];

        SqlConnection conn = new SqlConnection (cts.ConnectionString);
      SqlCommand sc =
        new SqlCommand(" SELECT FirstName,LastName,Title,TitleOfCourtesy,ReportsTo " +
                       " FROM Employees " +
                       " WHERE EmployeeID = @empId",
                       conn);
      // Add the employee ID parameter and set its value.
      sc.Parameters.Add(new SqlParameter("@empId",SqlDbType.Int)).Value = Int32.Parse(anID.ToString());
      SqlDataReader sdr = null;

      try {
        conn.Open();
        sdr = sc.ExecuteReader();

        // This is not a while loop. It only loops once.
        if (sdr != null && sdr.Read()) {
          // The IEnumerable contains DataRowView objects.
          this.firstName        = sdr["FirstName"].ToString();
          this.lastName         = sdr["LastName"].ToString();
          this.title            = sdr["Title"].ToString();
          this.titleOfCourtesy  = sdr["TitleOfCourtesy"].ToString();
          if (!sdr.IsDBNull(4)) {
            this.reportsTo        = sdr.GetInt32(4);
          }
        }
        else {
          throw new NorthwindDataException("Data not loaded for employee id.");
        }
      }
      finally {
        try {
          if (sdr != null) sdr.Close();
          conn.Close();
        }
        catch (SqlException) {
          // Log an event in the Application Event Log.
          throw;
        }
      }
    }

    private object ID;

    private string lastName;
    public string LastName {
      get { return lastName; }
      set { lastName = value; }
    }

    private string firstName;
    public string FirstName {
      get { return firstName; }
      set { firstName = value;  }
    }

    private string title;
    public String Title {
      get { return title; }
      set { title = value; }
    }

    private string titleOfCourtesy;
    public string Courtesy {
      get { return titleOfCourtesy; }
      set { titleOfCourtesy = value; }
    }

    private int    reportsTo;
    public int Supervisor {
      get { return reportsTo; }
      set { reportsTo = value; }
    }

    public bool Save () {
      return true;
    }
  }

  internal class NorthwindDataException: Exception {
    public NorthwindDataException(string msg) : base (msg) { }
  }
}

備註

若要建立控件系結的物件實例 ObjectDataSource ，控件會使用反映載入運行時間由類型名稱所識別的類型。 因此，屬性的值 TypeName 可以是位於 Bin 或 App_Code 目錄中之程式代碼的部分限定型別，或是全域程式集緩存中註冊之程式代碼的完整型別名稱。 如果您使用全域程式集緩存，您必須將適當的參考新增至 assemblies Machine.config 或 Web.config 檔案的 區段。

除非您處理 ObjectCreating 事件以自行建立實例，否則類型必須具有無參數建構函式。 如果 型別上的方法為成員方法，則會針對 、Update、 Insert和 Delete 方法的每個呼叫Select建立型別的實例。 如果在 Visual Basic) 中 (方法 static ， Shared 則不會建立實例。 如果型別實作 IDisposable 介面，則會 Dispose 在物件終結之前呼叫 方法。

適用於

產品 版本
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

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