我们可以自定义DataGridView的DataGridViewColumn来实现自定义的列，下面介绍一下如何通过扩展DataGridViewColumn来实现一个TreeViewColumn
我们可以自定义DataGridView的DataGridViewColumn来实现自定义的列，下面介绍一下如何通过扩展DataGridViewColumn来实现一个TreeViewColumn
1.TreeViewColumn类
TreeViewColumn继承自DataGridViewColumn，为了动态给TreeViewColumn传入一个TreeView，这里暴露出一个公共属性_root，可以绑定一个初始化的TreeView. 另外需要重写DataGridCell类型的CellTemplate，这里返还一个TreeViewCell（需要自定义）
/// <summary>
/// Host TreeView In DataGridView Cell
/// </summary>
public class TreeViewColumn : DataGridViewColumn
{
public TreeViewColumn()
: base(new TreeViewCell())
{
}
[Description("Set TreeView Root in DataGridView Cell"), Category("TreeView")]
public TreeView _root
{
get{return Roots.tree;}
set{Roots.tree=value;}
}
public override DataGridViewCell CellTemplate
{
get
{
return base.CellTemplate;
}
set
{
// Ensure that the cell used for the template is a TreeViewCell.
if (value != null &&
!value.GetType().IsAssignableFrom(typeof(TreeViewCell)))
{
throw new InvalidCastException("Must be a TreeViewCell");
}
base.CellTemplate = value;
}
}
}
2.TreeViewCell类
上面TreeViewColumn重写了CellTemplate，返回的就是自定义的TreeViewCell，这里就是具体实现其逻辑。一般来说选择树控件的节点后，返回的是一个文本信息，是文本类型，可以继承DataGridViewTextBoxCell,并重写InitializeEditingControl来进行自定义的DataGridView.EditingControl （编辑控件）。
public class TreeViewCell : DataGridViewTextBoxCell
{
public TreeViewCell()
: base()
{
//初始设置
}
public override void InitializeEditingControl(int rowIndex, object
initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle)
{
// Set the value of the editing control to the current cell value.
base.InitializeEditingControl(rowIndex, initialFormattedValue,
dataGridViewCellStyle);
TreeViewEditingControl ctl =
DataGridView.EditingControl as TreeViewEditingControl;
// Use the default row value when Value property is null.
if (this.Value == null)
{
ctl.SelectedNode =new TreeNode( this.DefaultNewRowValue.ToString());
}
else
{
ctl.SelectedNode = new TreeNode(this.Value.ToString());
}
}
public override Type EditType
{
get
{
// Return the type of the editing control that CalendarCell uses.
return typeof(TreeViewEditingControl);
}
}
public override Type ValueType
{
get
{
// Return the type of the value that CalendarCell contains.
return typeof(String);
}
}
public override object DefaultNewRowValue
{
get
{
// Use the current date and time as the default value.
return "";
}
}
}
