下拉框

VB下拉框绑定数据

Public Overloads Shared Function SetComboxNameID(ByVal dsCmb As DataSet, ByRef cmb As ComboBox, ByVal flag As Integer) As ComboBox
        Dim intIndex As Integer
        Dim dsRow As DataRow
        Dim ds As DataSet
        ds = dsCmb.Clone			'复制表结构
        If flag = 1 Then
            '不添加一条新的空记录
        End If
        If flag = 2 Then
            '添加一条新的空记录
            dsRow = ds.Tables(0).NewRow
            dsRow.Item(0) = ""
            dsRow.Item(1) = ""
            ds.Tables(0).Rows.Add(dsRow)
        End If
        If flag = 3 Then
            '添加一条新记录“请选择．．．”
            'dsRow.Item(ds.Tables(0).Columns(0).ColumnName) = "请选择..."
            dsRow = ds.Tables(0).NewRow
            dsRow.Item(0) = ""
            dsRow.Item(1) = "请选择..."
            ds.Tables(0).Rows.Add(dsRow)
        End If
        For intIndex = 0 To dsCmb.Tables(0).Rows.Count - 1
            dsRow = ds.Tables(0).NewRow
            dsRow.Item(ds.Tables(0).Columns(0).ColumnName) = dsCmb.Tables(0).Rows(intIndex).Item(0)
            dsRow.Item(ds.Tables(0).Columns(1).ColumnName) = dsCmb.Tables(0).Rows(intIndex).Item(1)
            ds.Tables(0).Rows.Add(dsRow)
        Next intIndex
        '显示第二列
        cmb.DisplayMember = ds.Tables(0).Columns(1).ColumnName
        '隐藏第一列
        cmb.ValueMember = ds.Tables(0).Columns(0).ColumnName
        cmb.DataSource = ds.Tables(0)
        Return cmb
  End Function

'①清空下拉框的数据   
comboBox1.SelectedIndex = -1
'清空选中项写法：  
comboBox1.text= ""
'清空items时写法： 
comboBox1.Items.Clear()
'清空DataTable时写法
'①清空ComboBox的DataSource, 清空DataSet对象，都不行，清空数据集中的表
ds.Table.clear()
'②再绑定一次
Dim ds As DataSet           '清空下拉框
comboBox1.DataSource = ds

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下拉框数据自动补全属性设置后，清空掉上一次下拉框的数据

 //清掉上一次系列的缓存
 comboBox1.AutoCompleteSource = AutoCompleteSource.None
 comboBox1.AutoCompleteSource = AutoCompleteSource.ListItems

设置下拉框属性 数据自动补全

C

C#下拉框 数据绑定

private void BtnConnection_Click(object sender, EventArgs e)
 {
     //获取所有表名 datatable
     dt = ExecuteTable("SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE ='BASE TABLE'");
     //添加一行(全选)
     DataRow dr = dt.NewRow();
     dr["TABLE_NAME"] = "全选";
     //dt.Rows.Add(dr);  		//加到最后
     dt.Rows.InsertAt(dr, 0); 		//加到指定位置（第一行）
     //绑定数据到下拉框
     cmbTableName.DataSource = dt;
     cmbTableName.DisplayMember = "TABLE_NAME";  	//显示的值
     cmbTableName.ValueMember = "TABLE_NAME"; 		//选中的值
 }