下面是详细讲解“C#自定义DataGridViewColumn显示TreeView”的完整攻略：
1. 实现自定义DataGridViewColumn
首先，我们需要实现一个自定义的DataGridViewColumn类来支持TreeView的显示和编辑。
public class DataGridViewTreeViewColumn : DataGridViewColumn
{
public DataGridViewTreeViewColumn()
: base(new DataGridViewTreeViewCell())
{
}
public override DataGridViewCell CellTemplate
{
get
{
return base.CellTemplate;
}
set
{
// Ensure that the cell used for the template is a DataGridViewTreeViewCell.
if (value != null && !value.GetType().IsAssignableFrom(typeof(DataGridViewTreeViewCell)))
{
throw new InvalidCastException("DataGridViewTreeViewColumn requires a DataGridViewTreeViewCell cell");
}
base.CellTemplate = value;
}
}
public TreeView TreeView
{
get
{
return (base.CellTemplate as DataGridViewTreeViewCell).TreeView;
}
set
{
(base.CellTemplate as DataGridViewTreeViewCell).TreeView = value;
}
}
}
这个类继承自DataGridViewColumn，其中包含了一个自定义的DataGridViewTreeViewCell单元格类型以支持TreeView的显示和编辑。
2. 实现自定义DataGridViewCell
然后，我们需要实现一个自定义的DataGridViewCell类来具体实现TreeView的显示和编辑。
public class DataGridViewTreeViewCell : DataGridViewTextBoxCell
{
private TreeView treeView = new TreeView();
public DataGridViewTreeViewCell()
{
treeView.BorderStyle = BorderStyle.None;
treeView.Leave += new EventHandler(TreeView_Leave);
treeView.AfterSelect += new TreeViewEventHandler(TreeView_AfterSelect);
treeView.KeyDown += new KeyEventHandler(TreeView_KeyDown);
treeView.VisibleChanged += new EventHandler(TreeView_VisibleChanged);
}
public TreeView TreeView
{
get { return treeView; }
set { treeView = value; }
}
public override void InitializeEditingControl(int rowIndex, object initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle)
{
base.InitializeEditingControl(rowIndex, initialFormattedValue, dataGridViewCellStyle);
DataGridViewTreeViewEditingControl ctl = (DataGridViewTreeViewEditingControl)DataGridView.EditingControl;
ctl.TreeView = treeView;
ctl.SelectedValue = (string)Value;
}
public override object ParseFormattedValue(object formattedValue, DataGridViewCellStyle cellStyle, TypeConverter formattedValueTypeConverter, TypeConverter valueTypeConverter)
{
return ((DataGridViewTreeViewEditingControl)DataGridView.EditingControl).SelectedValue;
}
protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts)
{
if (treeView != null && treeView.Visible)
{
var bmp = new Bitmap(treeView.Width, treeView.Height);
treeView.DrawToBitmap(bmp, treeView.ClientRectangle);
graphics.DrawImage(bmp, cellBounds.Location);
}
else
{
base.Paint(graphics, clipBounds, cellBounds, rowIndex, cellState, value, formattedValue, errorText, cellStyle, advancedBorderStyle, paintParts);
}
}
private void TreeView_Leave(object sender, EventArgs e)
{
if (base.DataGridView != null)
{
DataGridView.EndEdit();
}
}
private void TreeView_AfterSelect(object sender, TreeViewEventArgs e)
{
base.Value = e.Node.Name;
base.DataGridView.NotifyCurrentCellDirty(true);
}
private void TreeView_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter || e.KeyData == Keys.Tab)
{
DataGridView.EndEdit();
}
else if (e.KeyCode == Keys.Escape)
{
DataGridView.CancelEdit();
}
}
private void TreeView_VisibleChanged(object sender, EventArgs e)
{
if (!treeView.Visible)
{
base.DataGridView.EndEdit();
}
}
public override void DetachEditingControl()
{
var dataGridViewTreeViewEditingControl = DataGridView.EditingControl as DataGridViewTreeViewEditingControl;
if (dataGridViewTreeViewEditingControl != null)
{
dataGridViewTreeViewEditingControl.TreeView = null;
}
base.DetachEditingControl();
}
}
这个类继承自DataGridViewTextBoxCell，主要实现了如下几个功能：
- 在InitializeEditingControl方法中，设置了自定义的DataGridViewTreeViewEditingControl控件的TreeView属性，将TreeView显示在编辑控件中；
- 在ParseFormattedValue方法中，返回自定义的DataGridViewTreeViewEditingControl控件的SelectedValue属性，以便在保存数据时获取TreeView的选中值；
- 在Paint方法中，判断TreeView是否可见，如果可见则将其绘制出来；
- 在TreeView的事件处理中，将选中的节点的Name属性赋给Value属性，并在编辑控件失去焦点时提交修改。
3. 实现自定义DataGridViewEditingControl
最后，我们需要实现一个自定义的DataGridViewEditingControl类来支持TreeView的编辑。
public class DataGridViewTreeViewEditingControl : UserControl, IDataGridViewEditingControl
{
private TreeView treeView;
private string selectedValue;
private bool valueChanged = false;
private int rowIndex;
public DataGridViewTreeViewEditingControl()
{
InitializeComponent();
}
private void InitializeComponent()
{
Dock = DockStyle.Fill;
Controls.Add(treeView);
treeView.AfterSelect += new TreeViewEventHandler(TreeView_AfterSelect);
treeView.KeyDown += new KeyEventHandler(TreeView_KeyDown);
}
public TreeView TreeView
{
get { return treeView; }
set { treeView = value; }
}
public string SelectedValue
{
get { return selectedValue; }
set { selectedValue = value; }
}
public bool EditingControlValueChanged
{
get { return valueChanged; }
set { valueChanged = value; }
}
public object EditingControlFormattedValue
{
get { return GetValue(); }
set { SetValue(value); }
}
public int EditingControlRowIndex
{
get { return rowIndex; }
set { rowIndex = value; }
}
public bool RepositionEditingControlOnValueChange
{
get { return false; }
}
public DataGridView EditingControlDataGridView { get; set; }
public Cursor EditingPanelCursor { get { return base.Cursor; } }
public bool EditingControlWantsInputKey(Keys keyData, bool dataGridViewWantsInputKey)
{
switch (keyData & 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:
case Keys.Escape:
return true;
default:
return !dataGridViewWantsInputKey;
}
}
public object GetEditingControlFormattedValue(DataGridViewDataErrorContexts context)
{
return GetValue();
}
public void ApplyCellStyleToEditingControl(DataGridViewCellStyle dataGridViewCellStyle)
{
treeView.BackColor = dataGridViewCellStyle.BackColor;
treeView.ForeColor = dataGridViewCellStyle.ForeColor;
treeView.Font = dataGridViewCellStyle.Font;
}
public void PrepareEditingControlForEdit(bool selectAll)
{
if (string.IsNullOrEmpty(selectedValue))
{
treeView.SelectedNode = null;
}
else
{
var node = GetNodeByValue(treeView.Nodes, selectedValue);
if (node != null)
{
treeView.SelectedNode = node;
}
else
{
treeView.SelectedNode = null;
}
}
}
private TreeNode GetNodeByValue(TreeNodeCollection nodes, string value)
{
foreach (TreeNode node in nodes)
{
if (node.Name == value)
{
return node;
}
else if (node.Nodes.Count > 0)
{
var node1 = GetNodeByValue(node.Nodes, value);
if (node1 != null)
{
return node1;
}
}
}
return null;
}
private object GetValue()
{
if (treeView.SelectedNode != null)
{
return treeView.SelectedNode.Name;
}
else
{
return string.Empty;
}
}
private void SetValue(object value)
{
if (value != null)
{
selectedValue = value.ToString();
}
else
{
selectedValue = string.Empty;
}
PrepareEditingControlForEdit(false);
}
private void TreeView_AfterSelect(object sender, TreeViewEventArgs e)
{
EditingControlValueChanged = true;
EditingControlDataGridView.NotifyCurrentCellDirty(true);
}
private void TreeView_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter || e.KeyData == Keys.Tab)
{
EditingControlDataGridView.EndEdit();
}
else if (e.KeyCode == Keys.Escape)
{
EditingControlDataGridView.CancelEdit();
}
}
}
这个控件实现了IDataGridViewEditingControl接口，并包含了一个选项树（TreeView）以及相关的事件处理和数据存取方法。
4. 示例
下面是一个简单的示例使用自定义DataGridViewTreeViewColumn：
public class DemoForm : Form
{
private DataGridView dataGridView1;
public DemoForm()
{
InitializeDataGridView();
}
private void InitializeDataGridView()
{
var column = new DataGridViewTreeViewColumn();
column.Name = "TreeViewColumn";
column.HeaderText = "TreeView Column";
var data = new DataTable();
data.Columns.Add("TreeViewColumn");
for (int i = 1; i <= 10; i++)
{
var row = data.NewRow();
row["TreeViewColumn"] = "Node" + i;
data.Rows.Add(row);
if (i == 1 || i == 6)
{
for (int j = 1; j <= 5; j++)
{
var childRow = data.NewRow();
childRow["TreeViewColumn"] = "Node" + i + "-" + j;
data.Rows.Add(childRow);
}
}
}
dataGridView1 = new DataGridView();
dataGridView1.Dock = DockStyle.Fill;
dataGridView1.AutoGenerateColumns = false;
dataGridView1.Columns.Add(column);
dataGridView1.DataSource = data;
Controls.Add(dataGridView1);
}
}
这个示例使用TreeView Column作为DataGridView中的一列，并设置数据源为DataTable，其中包含了一些以“Node”为名称的节点以及部分子节点。
另外，我们还可以使用TreeView控件的各种方法和属性对TreeView进行进一步的自定义和调整，例如设置显示模式、节点图标以及自定义绘制等。详细内容可以参考MSDN文档。
本站文章如无特殊说明，均为本站原创，如若转载，请注明出处：C#自定义DataGridViewColumn显示TreeView - Python技术站
微信扫一扫 
支付宝扫一扫 