作者:海雅

一、取得數(shù)據(jù)表 i 行 j 列的值  

     //建立并打開數(shù)據(jù)庫連接
    OleDbConnection conn=new OleDbConnection();
    conn.ConnectionString=strConnectionString;//strConnectionString為數(shù)據(jù)庫連接字符串
    conn.Open();

    string sql="select * from NewsClass order by ClassId desc";
    string x;
    DataSet ds=new DataSet();
    OleDbDataAdapter da=new OleDbDataAdapter(sql,conn); 
    da.Fill(ds,"NewsTable");
    DataTable dt=ds.Tables["NewsTable"];
    x=dt.Rows[i][1].ToString()//數(shù)據(jù)表i行j列的值 
    conn.close();

二、將數(shù)據(jù)讀入DropDownList

（1）  DropDownList中添加數(shù)據(jù)

  //建立并打開數(shù)據(jù)庫連接
    OleDbConnection conn=new OleDbConnection();
    conn.ConnectionString=strConnectionString;//strConnectionString為數(shù)據(jù)庫連接字符串
    conn.Open();

    string sql="select * from NewsClass order by ClassId desc";
    //建立數(shù)據(jù)集
    DataSet ds=new DataSet();
    OleDbDataAdapter da=new OleDbDataAdapter(sql,conn); 
    da.Fill(ds,"NewsTable");
    this.DropDownList1.DataSource=ds;
    this.DropDownList1.DataTextField = "ClassName";//Text值
    this.DropDownList1.DataValueField = "ClassID";//Value值
    this.DropDownList1.DataBind();
   
    conn.Close();

（2）選中DropDownList的某項

this.DropDownList1.Items.FindByValue(dr["ClassID"].ToString().Trim()).Selected=true;//dr為DataRow

三、分類編碼檢索出相應的分類名稱并在DataGrid中顯示

（1）.aspX中的代碼（ClassID為分類編碼）：

    <asp:TemplateColumn HeaderText="類 別">
         <ItemTemplate>
          <asp:Label id=lblClass runat="server" Text='<%# GetClassName(Convert.ToInt32(DataBinder.Eval(Container, "DataItem.ClassID"))) %>'>
          </asp:Label>
         </ItemTemplate>
        </asp:TemplateColumn>

（2）C#代碼：

 /// <summary>
  /// "分類"列根據(jù)數(shù)字返回文字
  /// </summary>
  /// <param name="IsPassed"></param>
  /// <returns></returns>
  public string  GetClassName(int ClassID)
  {
   OleDbConnection conn=new OleDbConnection();
   conn.ConnectionString=strConnectionString;
   conn.Open();

   string sql="select * from NewsClass where ClassID="+ClassID;
   DataSet ds=new DataSet();
   OleDbDataAdapter da=new OleDbDataAdapter(sql,conn);
   da.Fill(ds,"ClassTable");
   DataTable dt=ds.Tables["ClassTable"];
   string strClassName=dt.Rows[0]["ClassName"].ToString();
   conn.Close();

   return strClassName;//返回 ClassID對應的ClassName
  }