C# winform： ComboBox 設置下拉框數據源的公共方法

public static void SetComboList(ComboBox cboSource, string sSQL,string sWindowTxt,string sFirstItem="",DataTable dtSource=null) 

{ 

    string sError = string.Empty; 

    DataTable dt=null; 

    if (!string.IsNullOrEmpty(sSQL)) 

    { 

        dt = SqlLiteHelper.GetDataTable(out sError, sSQL); 

        if (!string.IsNullOrEmpty(sError)) 

            Common.DisplayMsg(sWindowTxt, sError); 

    } 

    else if (dtSource != null) 

    { 

        dt = dtSource.Copy(); 

    } 

    if (!string.IsNullOrEmpty(sFirstItem)) 

    { 

        DataRow dr = dt.NewRow(); 

        dr[0] = -1; 

        dr[1] = sFirstItem; 

        dt.Rows.InsertAt(dr, 0); 

    } 

    //cboSource.Items.Clear(); 

    cboSource.DataSource = dt; 

    cboSource.ValueMember = dt.Columns[0].ColumnName; 

    cboSource.DisplayMember = dt.Columns[1].ColumnName; 

    cboSource.DropDownStyle = ComboBoxStyle.DropDownList; 

} 

 1, 初始化下拉框數據源 例子：

            string sSql = "select id,value from tgExpenditureItem";

            Common.SetComboList(cboOutputItem, sSql, this.Text);

 或     

            DataTable dtSource = new DataTable();

            dtSource.Columns.Add("id");

            dtSource.Columns.Add("value");

            dtSource.Rows.Add(1, "aa");

            dtSource.Rows.Add(2, "bb");

            dtSource.Rows.Add(3,"cc");

            Common.SetComboList(cboOutputItem, "", this.Text, "(全部)", dtSource);

2,  取值可以通過

cboOutputItem.SelectedIndex 

                cboOutputItem.SelectedItem.ToString()

                    cboOutputItem.SelectedValue  等方式來取        

3,  SqlLiteHelper 類請參考：

             用於sqlite數據庫的SqlLiteHelper.cs 的類：http://www.BkJia.com/kf/201111/111180.html

摘自 keenweiwei的專欄