我想为 DataGridView 创建一个 TreeView 列。我已经按照此处的示例扩展了 TreeView，如下所示。
public class TreeViewEditingControl : TreeView, IDataGridViewEditingControl
public class TreeViewCell : DataGridViewComboBoxCell // Not sure whether this should be DataGridViewTextBoxCell
这是我的问题。我可以在单元格中看到 Treeview，但我不知道当用户单击单元格时如何增加 Cell/TreeView 的高度（当 ComboBox 展开时）。有人对此有任何想法吗？
我会生成一个新的无边框表单，里面有一个 TreeCtrl Docked，我用 CalendarControl 完成了这个，效果很好。如果您将表单的左上角设置为正在编辑的单元格的左上角，用户将不会知道其中的区别。希望这是您正在寻找的。
编辑：
这是我为文件选择单元所做的实现。它有一个浏览按钮，当您单击它进行编辑时，它会出现在单元格中，并打开一个 FileOpenDialog。代码很长，但我认为你可以挑选出你需要实现的部分。
public class DataGridViewFileColumn : DataGridViewColumn
{
public DataGridViewFileColumn() : base(new DataGridViewFileCell())
{
BrowseLabel = "...";
SaveFullPath = false;
}
public override DataGridViewCell CellTemplate
{
get
{
return base.CellTemplate;
}
set
{
// Ensure that the cell used for the template is a DataGridViewFileCell.
if (value != null &&
!value.GetType().IsAssignableFrom(typeof(DataGridViewFileCell)))
{
throw new InvalidCastException("Must be a DataGridViewFileCell");
}
base.CellTemplate = value;
}
}
[Description("Label to place on Browse button"),Category("Appearance")]
[DefaultValue("...")]
public string BrowseLabel
{
get;
set;
}
[Description("Save full path name"), Category("Behavior")]
[DefaultValue(true)]
public bool SaveFullPath
{
get;
set;
}
}
public class DataGridViewFileCell : DataGridViewTextBoxCell
{
public DataGridViewFileCell() : base()
{
}
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);
FileEditingControl ctl = (FileEditingControl)DataGridView.EditingControl;
// Use the default row value when Value property is null.
if (this.Value == null)
{
ctl.Filename = this.DefaultNewRowValue.ToString();
}
else
{
ctl.Filename = this.Value.ToString();
}
}
public override Type EditType
{
get
{
// Return the type of the editing control that DataGridViewFileCell uses.
return typeof(FileEditingControl);
}
}
public override Type ValueType
{
get
{
// Return the type of the value that DataGridViewFileCell contains.
return typeof(string);
}
}
}
class FileEditingControl : FileTextBox, IDataGridViewEditingControl
{
DataGridView dataGridView;
private bool valueChanged = false;
int rowIndex;
public FileEditingControl()
{
}
#region IDataGridViewEditingControl implementations
public object EditingControlFormattedValue
{
get
{
return Filename;
}
set
{
if (value is String)
{
try
{
Filename = (String)value;
}
catch
{
Filename = value.ToString();
}
}
}
}
public object GetEditingControlFormattedValue(
DataGridViewDataErrorContexts context)
{
return EditingControlFormattedValue;
}
public void ApplyCellStyleToEditingControl(
DataGridViewCellStyle dataGridViewCellStyle)
{
this.Font = dataGridViewCellStyle.Font;
}
public int EditingControlRowIndex
{
get
{
return rowIndex;
}
set
{
rowIndex = value;
}
}
public bool EditingControlWantsInputKey(
Keys key, bool dataGridViewWantsInputKey)
{
switch (key & Keys.KeyCode)
{
case Keys.Left:
case Keys.Up:
case Keys.Down:
case Keys.Right:
case Keys.Home:
case Keys.End:
case Keys.PageDown:
case Keys.PageUp:
return true;
default:
return !dataGridViewWantsInputKey;
}
}
public void PrepareEditingControlForEdit(bool selectAll)
{
}
public bool RepositionEditingControlOnValueChange
{
get
{
return false;
}
}
public DataGridView EditingControlDataGridView
{
get
{
return dataGridView;
}
set
{
dataGridView = value;
}
}
public bool EditingControlValueChanged
{
get
{
return valueChanged;
}
set
{
valueChanged = value;
}
}
public Cursor EditingPanelCursor
{
get
{
return base.Cursor;
}
}
#endregion
protected override void OnValueChanged(FileEventArgs eventargs)
{
// Notify the DataGridView that the contents of the cell
// have changed.
valueChanged = true;
this.EditingControlDataGridView.NotifyCurrentCellDirty(true);
base.OnValueChanged(eventargs);
}
}
public partial class FileTextBox : UserControl
{
#region Constructors
public FileTextBox()
{
InitializeComponent();
Tooltip = new ToolTip();
SaveFullPath = false;
AllowMultipleFiles = false;
BrowseLabel = "...";
}
#endregion Constructors
#region Properties
/// <summary>
/// Tooltip object used to show full path name
/// </summary>
private ToolTip Tooltip;
/// <summary>
/// Return the full path or just the filename?
/// </summary>
[Description("Save Full Path"), Category("Behavior")]
[DefaultValue(false)]
public bool SaveFullPath
{
get;
set;
}
/// <summary>
/// String representing the filename for this control
/// </summary>
public override string Text
{
get
{
return base.Text;
}
set
{
if (base.Text != value)
{
base.Text = value;
Tooltip.SetToolTip(this, base.Text);
Invalidate();
OnValueChanged(new FileEventArgs(base.Text));
}
}
}
[Description("Browse Label"), Category("Appearance")]
[DefaultValue("...")]
public string BrowseLabel
{
get
{
return Browse.Text;
}
set
{
Browse.Text = value;
Browse.Width = TextRenderer.MeasureText(Browse.Text, Browse.Font).Width + 8;
Browse.Location = new Point(this.Width - Browse.Width, Browse.Location.Y);
}
}
[Description("Allow Multiple Files"), Category("Behavior")]
[DefaultValue(false)]
public bool AllowMultipleFiles
{
get;
set;
}
/// <summary>
/// Selected filename (same as Text property)
/// </summary>
[Description("Filename"), Category("Data")]
public string Filename
{
get { return Text; }
set { Text = value; }
}
#endregion Properties
#region Event Handlers
/// <summary>
/// Event raised when
/// </summary>
public event EventHandler ValueChanged;
protected virtual void OnValueChanged(FileEventArgs eventargs)
{
eventargs.Filename = Filename;
if (this.ValueChanged != null)
this.ValueChanged(this, eventargs);
}
private void Browse_Click(object sender, EventArgs e)
{
OpenFileDialog dlg = new OpenFileDialog();
dlg.FileName = Text;
dlg.Multiselect = AllowMultipleFiles;
if (dlg.ShowDialog() == DialogResult.OK)
{
if (SaveFullPath)
Text = dlg.FileName;
else
Text = dlg.SafeFileName;
}
}
protected override void OnPaint(PaintEventArgs e)
{
// Draw the client window
Rectangle r = new Rectangle(new Point(0, 0), new Size(Size.Width-1, Size.Height-1));
Graphics g = e.Graphics;
g.FillRectangle(new SolidBrush(SystemColors.Window), r);
g.DrawRectangle(new Pen(VisualStyleInformation.TextControlBorder), r);
r.Y += Margin.Top;
r.Width -= Browse.Width;
// Fill with Text
TextRenderer.DrawText(g, Text, Font, r, ForeColor, TextFormatFlags.PathEllipsis);
base.OnPaint(e);
}
private void FileTextBox_DragDrop(object sender, DragEventArgs e)
{
DataObject data = (DataObject)e.Data;
StringCollection filenames = data.GetFileDropList();
if ( filenames.Count == 1)
Text = filenames[0];
}
private void FileTextBox_DragEnter(object sender, DragEventArgs e)
{
DataObject data = (DataObject)e.Data;
StringCollection filenames = data.GetFileDropList();
if (/*!AllowMultipleFiles &&*/ filenames.Count == 1)
e.Effect = DragDropEffects.Link;
}
#endregion Event Handlers
}
public class FileEventArgs : EventArgs
{
public FileEventArgs(string Text)
{
Filename = Text;
}
/// <summary>
/// Name of the file in the control
/// </summary>
public String Filename { get; set; }
}