ExpandメソッドおよびCollapseメソッドを使用して列の表示／非表示を切り替えることができます。

[Visual Basic]

Imports GrapeCity.Win.MultiRow

Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
　　Dim textBoxCell1 As TextBoxCell = New TextBoxCell()
　　textBoxCell1.Name = "textBoxCell1"
　　Dim textBoxCell2 As TextBoxCell = New TextBoxCell()
　　textBoxCell2.Name = "textBoxCell2"
　　Dim textBoxCell3 As TextBoxCell = New TextBoxCell()
　　textBoxCell3.Name = "textBoxCell3"

　　GcMultiRow1.Template = Template.CreateGridTemplate(New Cell() {textBoxCell1, textBoxCell2, textBoxCell3})
End Sub

Private Sub Button1_Click_1(sender As System.Object, e As System.EventArgs) Handles Button1.Click
　　If GcMultiRow1.Columns(1).IsCollapsed = True Then
　　　　GcMultiRow1.Columns(1).Expand()
　　Else
　　　　GcMultiRow1.Columns(1).Collapse()
　　End If
End Sub

[C#]

using GrapeCity.Win.MultiRow;

private void Form1_Load(object sender, EventArgs e)
{
　　TextBoxCell textBoxCell1 = new TextBoxCell();
　　textBoxCell1.Name = "textBoxCell1";
　　TextBoxCell textBoxCell2 = new TextBoxCell();
　　textBoxCell2.Name = "textBoxCell2";
　　TextBoxCell textBoxCell3 = new TextBoxCell();
　　textBoxCell3.Name = "textBoxCell3";

　　gcMultiRow1.Template = Template.CreateGridTemplate(new Cell[] { textBoxCell1, textBoxCell2, textBoxCell3 });
}

private void button1_Click(object sender, EventArgs e)
{
　　if (gcMultiRow1.Columns[1].IsCollapsed == true)
　　{
　　　　gcMultiRow1.Columns[1].Expand();
　　}
　　else
　　{
　　　　gcMultiRow1.Columns[1].Collapse();
　　}
}