在DataGrid中简单使用下拉列表框
作者：Tushar Ameta
翻译：秋枫
在DataGrid中使用下拉列表问题。这篇文章讲了如何在 System.Windows.Forms.DataGrid中切入使用ComboBox控件。不过原文不全，无法调试，在这里为了说清楚点，对原文作了一些修改，整篇文章主要包括三方面的内容。
1． 在DataGrid中加入ComboBox列；
2． 把在DataGrid中的修改保存到对应的网格；
3． 设置DataGrid中网格的焦点。
下面是整个源代码，一些功能可以看注释。
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace DataGridTest
{
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.DataGrid dgdFunctionArea;
private DataTable dtblFunctionalArea;
private System.Windows.Forms.Button buttonFocus;
private System.ComponentModel.Container components = null;
public Form1()
{
InitializeComponent();
PopulateGrid();
}
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows 窗体设计器生成的代码
private void InitializeComponent()
{
this.dgdFunctionArea = new System.Windows.Forms.DataGrid();
this.buttonFocus = new System.Windows.Forms.Button();
((System.ComponentModel.ISupportInitialize)(this.dgdFunctionArea)).BeginInit();
this.SuspendLayout();
//
// dgdFunctionArea
//
this.dgdFunctionArea.DataMember = "";
this.dgdFunctionArea.HeaderForeColor = System.Drawing.SystemColors.ControlText;
this.dgdFunctionArea.Location = new System.Drawing.Point(4, 8);
this.dgdFunctionArea.Name = "dgdFunctionArea";
this.dgdFunctionArea.Size = new System.Drawing.Size(316, 168);
this.dgdFunctionArea.TabIndex = 0;
//
// buttonFocus
//
this.buttonFocus.Location = new System.Drawing.Point(232, 188);
this.buttonFocus.Name = "buttonFocus";
this.buttonFocus.Size = new System.Drawing.Size(84, 23);
this.buttonFocus.TabIndex = 1;
this.buttonFocus.Text = "获取焦点";
this.buttonFocus.Click += new System.EventHandler(this.buttonFocus_Click);
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
this.ClientSize = new System.Drawing.Size(332, 217);
this.Controls.Add(this.buttonFocus);
this.Controls.Add(this.dgdFunctionArea);
this.Name = "Form1";
this.Text = "Form1";
((System.ComponentModel.ISupportInitialize)(this.dgdFunctionArea)).EndInit();
this.ResumeLayout(false);
}
#endregion
/// <summary>
/// 应用程序的主入口点。
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
//初始化DataGrid
private void PopulateGrid()
{
//创建一个DataTable对象，包括四列，前三列为String，最后一列为Boolean。
dtblFunctionalArea = new DataTable ("FunctionArea");
string[] arrstrFunctionalArea = new string [3]{"Functional Area","Min","Max"};
DataColumn dtCol = null;
//创建String列
for(int i=0; i< 3;i++)
{
dtCol = new DataColumn(arrstrFunctionalArea[i]);
dtCol.DataType = Type.GetType("System.String");
dtCol.DefaultValue = "";
dtblFunctionalArea.Columns.Add(dtCol);
}
//创建Boolean列，用CheckedBox来显示。
DataColumn dtcCheck = new DataColumn("IsMandatory");
dtcCheck.DataType = System.Type.GetType("System.Boolean");
dtcCheck.DefaultValue = false;
dtblFunctionalArea.Columns.Add(dtcCheck);
//把表绑定到DataGrid
dgdFunctionArea.DataSource = dtblFunctionalArea;
//为DataGrid加载DataGridTableStyle样式
if(!dgdFunctionArea.TableStyles.Contains("FunctionArea"))
{
DataGridTableStyle dgdtblStyle = new DataGridTableStyle();
dgdtblStyle.MappingName = dtblFunctionalArea.TableName;
dgdFunctionArea.TableStyles.Add(dgdtblStyle);
dgdtblStyle.RowHeadersVisible = false;
dgdtblStyle.HeaderBackColor = Color.LightSteelBlue;
dgdtblStyle.AllowSorting = false;
dgdtblStyle.HeaderBackColor = Color.FromArgb(8,36,107);
dgdtblStyle.RowHeadersVisible = false;
dgdtblStyle.HeaderForeColor = Color.White;
dgdtblStyle.HeaderFont = new System.Drawing.Font("Microsoft Sans Serif", 9F,
System.Drawing.FontStyle.Bold,
System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
dgdtblStyle.GridLineColor = Color.DarkGray;
dgdtblStyle.PreferredRowHeight = 22;
dgdFunctionArea.BackgroundColor = Color.White;
//设置列的宽度
GridColumnStylesCollection colStyle = dgdFunctionArea.TableStyles[0].GridColumnStyles;
colStyle[0].Width = 100;
colStyle[1].Width = 50;
colStyle[2].Width = 50;
colStyle[3].Width = 80;
}
DataGridTextBoxColumn dgtb = (DataGridTextBoxColumn)dgdFunctionArea.TableStyles[0].GridColumnStyles[0];
ComboBox cmbFunctionArea = new ComboBox();
cmbFunctionArea.Items.AddRange(new object[]{"选项一","选项二","选项三"});
cmbFunctionArea.Cursor = Cursors.Arrow;
cmbFunctionArea.DropDownStyle= ComboBoxStyle.DropDownList;
cmbFunctionArea.Dock = DockStyle.Fill;
//在选定项发生更改并且提交了该更改后发生
cmbFunctionArea.SelectionChangeCommitted += new EventHandler(cmbFunctionArea_SelectionChangeCommitted);
//把ComboBox添加到DataGridTableStyle的第一列
dgtb.TextBox.Controls.Add(cmbFunctionArea);
}
//设置焦点模拟
private void GetFocus(int row,int col)
{
//先把焦点移动到DataGrid
this.dgdFunctionArea.Focus();
//把焦点移动到DataGridCell
DataGridCell dgc = new DataGridCell(row,col);
this.dgdFunctionArea.CurrentCell = dgc;
DataGridTextBoxColumn dgtb = (DataGridTextBoxColumn)dgdFunctionArea.TableStyles[0].GridColumnStyles[col];
//设置焦点
dgtb.TextBox.Focus();
}
//把Combobox上修改的数据提交到当前的网格
private void cmbFunctionArea_SelectionChangeCommitted(object sender, EventArgs e)
{
this.dgdFunctionArea[this.dgdFunctionArea.CurrentCell] = ((ComboBox)sender).SelectedItem.ToString();
}
//设置新的焦点
private void buttonFocus_Click(object sender, System.EventArgs e)
{
//焦点模拟,这里设置第三行第一列
GetFocus(2,0);
}
}
}
下面是测试界面：
总结，这里是通过DataGridTextBoxColumn.TextBox.Controls.Add方法实现在列中添加ComboBox控件；对于数据的保存是使用ComboBox.SelectionChangeCommitted事件来完成；设置焦点是通过DataGridTextBoxColumn.TextBox.Focus方法来实现。另外通过这个方法也可以添加DateTimePicker等类似的控件。
