如何扩展行为和外观以自定义 Windows 窗体 DataGridView 控件中的单元格和列

2025-05-07

该 DataGridView 控件提供了多种方式来使用属性、事件和配套类自定义其外观和行为。有时，你可能对单元格的要求超出了这些功能所能提供的要求。可以创建自己的自定义 DataGridViewCell 类来提供扩展功能。

可以通过从DataGridViewCell基类或其派生类之一来创建自定义DataGridViewCell类。尽管可以在任何类型的列中显示任何类型的单元格，但通常还会创建专用于显示单元格类型的自定义 DataGridViewColumn 类。列类派生自 DataGridViewColumn 或其派生类型之一。

在下面的代码示例中，你将创建一个自定义单元格类，该类调用 DataGridViewRolloverCell 该类可检测鼠标何时进入并离开单元格边界。当鼠标位于单元格边界内时，将绘制一个内嵌矩形。此新类型派生自 DataGridViewTextBoxCell，在所有其他方面的行为都与其基类相同。伴随列类称为DataGridViewRolloverColumn。

若要使用这些类，请创建一个包含 DataGridView 控件的窗体，向集合中添加一个或多个 DataGridViewRolloverColumn 对象 Columns ，并使用包含值的行填充控件。

注释

如果添加空行，此示例将无法正常工作。例如，通过设置 RowCount 属性将行添加到控件时，会创建空行。这是因为在这种情况下添加的行会自动共享，意味着在单击各个单元格之前，DataGridViewRolloverCell 对象不会被实例化，从而导致关联的行变得不再共享。

由于这种类型的单元格自定义需要未共享的行，因此它不适合用于大型数据集。有关行共享的详细信息，请参阅有关缩放 Windows 窗体 DataGridView 控件的最佳做法。

注释

从 DataGridViewCell 或 DataGridViewColumn 派生并向派生类添加新属性时，请务必重写 Clone 方法，以在克隆操作期间复制新属性。还应调用基类 Clone 的方法，以便将基类的属性复制到新单元格或列。

自定义 DataGridView 控件中的单元格和列

从DataGridViewRolloverCell类型派生一个名为的新单元格类DataGridViewTextBoxCell。

public class DataGridViewRolloverCell : DataGridViewTextBoxCell
{

Public Class DataGridViewRolloverCell
    Inherits DataGridViewTextBoxCell

End Class

在Paint类中重写DataGridViewRolloverCell方法。在重写中，首先调用基类实现，该实现处理托管文本框功能。然后使用控件 PointToClient 的方法将光标位置（在屏幕坐标中）转换为 DataGridView 工作区的坐标。如果鼠标坐标位于单元格边界内，则绘制内嵌矩形。

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)
{
    // Call the base class method to paint the default cell appearance.
    base.Paint(graphics, clipBounds, cellBounds, rowIndex, cellState,
        value, formattedValue, errorText, cellStyle,
        advancedBorderStyle, paintParts);

    // Retrieve the client location of the mouse pointer.
    Point cursorPosition =
        this.DataGridView.PointToClient(Cursor.Position);

    // If the mouse pointer is over the current cell, draw a custom border.
    if (cellBounds.Contains(cursorPosition))
    {
        Rectangle newRect = new Rectangle(cellBounds.X + 1,
            cellBounds.Y + 1, cellBounds.Width - 4,
            cellBounds.Height - 4);
        graphics.DrawRectangle(Pens.Red, newRect);
    }
}

Protected Overrides Sub Paint( _
    ByVal graphics As Graphics, _
    ByVal clipBounds As Rectangle, _
    ByVal cellBounds As Rectangle, _
    ByVal rowIndex As Integer, _
    ByVal elementState As DataGridViewElementStates, _
    ByVal value As Object, _
    ByVal formattedValue As Object, _
    ByVal errorText As String, _
    ByVal cellStyle As DataGridViewCellStyle, _
    ByVal advancedBorderStyle As DataGridViewAdvancedBorderStyle, _
    ByVal paintParts As DataGridViewPaintParts)

    ' Call the base class method to paint the default cell appearance.
    MyBase.Paint(graphics, clipBounds, cellBounds, rowIndex, elementState, _
        value, formattedValue, errorText, cellStyle, _
        advancedBorderStyle, paintParts)

    ' Retrieve the client location of the mouse pointer.
    Dim cursorPosition As Point = _
        Me.DataGridView.PointToClient(Cursor.Position)

    ' If the mouse pointer is over the current cell, draw a custom border.
    If cellBounds.Contains(cursorPosition) Then
        Dim newRect As New Rectangle(cellBounds.X + 1, _
            cellBounds.Y + 1, cellBounds.Width - 4, _
            cellBounds.Height - 4)
        graphics.DrawRectangle(Pens.Red, newRect)
    End If

End Sub

重写OnMouseEnter类中的OnMouseLeave和DataGridViewRolloverCell方法，以强制单元格在鼠标指针进入或离开它们时重新绘制。

// Force the cell to repaint itself when the mouse pointer enters it.
protected override void OnMouseEnter(int rowIndex)
{
    this.DataGridView.InvalidateCell(this);
}

// Force the cell to repaint itself when the mouse pointer leaves it.
protected override void OnMouseLeave(int rowIndex)
{
    this.DataGridView.InvalidateCell(this);
}

' Force the cell to repaint itself when the mouse pointer enters it.
Protected Overrides Sub OnMouseEnter(ByVal rowIndex As Integer)
    Me.DataGridView.InvalidateCell(Me)
End Sub

' Force the cell to repaint itself when the mouse pointer leaves it.
Protected Overrides Sub OnMouseLeave(ByVal rowIndex As Integer)
    Me.DataGridView.InvalidateCell(Me)
End Sub

从DataGridViewRolloverCellColumn类型派生一个名为的新类DataGridViewColumn。在构造函数中，将新 DataGridViewRolloverCell 对象分配给其 CellTemplate 属性。

public class DataGridViewRolloverCellColumn : DataGridViewColumn
{
    public DataGridViewRolloverCellColumn()
    {
        this.CellTemplate = new DataGridViewRolloverCell();
    }
}

Public Class DataGridViewRolloverCellColumn
    Inherits DataGridViewColumn

    Public Sub New()
        Me.CellTemplate = New DataGridViewRolloverCell()
    End Sub

End Class

示例：

完整的代码示例包含一个小型测试表单，用于演示自定义单元格类型的行为。

using System;
using System.Drawing;
using System.Windows.Forms;

class Form1 : Form
{
    [STAThreadAttribute()]
    public static void Main()
    {
        Application.Run(new Form1());
    }

    public Form1()
    {
        DataGridView dataGridView1 = new DataGridView();
        DataGridViewRolloverCellColumn col =
            new DataGridViewRolloverCellColumn();
        dataGridView1.Columns.Add(col);
        dataGridView1.Rows.Add(new string[] { "" });
        dataGridView1.Rows.Add(new string[] { "" });
        dataGridView1.Rows.Add(new string[] { "" });
        dataGridView1.Rows.Add(new string[] { "" });
        this.Controls.Add(dataGridView1);
        this.Text = "DataGridView rollover-cell demo";
    }
}

public class DataGridViewRolloverCell : DataGridViewTextBoxCell
{
    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)
    {
        // Call the base class method to paint the default cell appearance.
        base.Paint(graphics, clipBounds, cellBounds, rowIndex, cellState,
            value, formattedValue, errorText, cellStyle,
            advancedBorderStyle, paintParts);

        // Retrieve the client location of the mouse pointer.
        Point cursorPosition =
            this.DataGridView.PointToClient(Cursor.Position);

        // If the mouse pointer is over the current cell, draw a custom border.
        if (cellBounds.Contains(cursorPosition))
        {
            Rectangle newRect = new Rectangle(cellBounds.X + 1,
                cellBounds.Y + 1, cellBounds.Width - 4,
                cellBounds.Height - 4);
            graphics.DrawRectangle(Pens.Red, newRect);
        }
    }

    // Force the cell to repaint itself when the mouse pointer enters it.
    protected override void OnMouseEnter(int rowIndex)
    {
        this.DataGridView.InvalidateCell(this);
    }

    // Force the cell to repaint itself when the mouse pointer leaves it.
    protected override void OnMouseLeave(int rowIndex)
    {
        this.DataGridView.InvalidateCell(this);
    }

}

public class DataGridViewRolloverCellColumn : DataGridViewColumn
{
    public DataGridViewRolloverCellColumn()
    {
        this.CellTemplate = new DataGridViewRolloverCell();
    }
}

Imports System.Drawing
Imports System.Windows.Forms

Class Form1
    Inherits Form

    <STAThreadAttribute()> _
    Public Shared Sub Main()
        Application.Run(New Form1())
    End Sub

    Public Sub New()
        Dim dataGridView1 As New DataGridView()
        Dim col As New DataGridViewRolloverCellColumn()
        dataGridView1.Columns.Add(col)
        dataGridView1.Rows.Add(New String() {""})
        dataGridView1.Rows.Add(New String() {""})
        dataGridView1.Rows.Add(New String() {""})
        dataGridView1.Rows.Add(New String() {""})
        Me.Controls.Add(dataGridView1)
        Me.Text = "DataGridView rollover-cell demo"
    End Sub

End Class

Public Class DataGridViewRolloverCell
    Inherits DataGridViewTextBoxCell

    Protected Overrides Sub Paint( _
        ByVal graphics As Graphics, _
        ByVal clipBounds As Rectangle, _
        ByVal cellBounds As Rectangle, _
        ByVal rowIndex As Integer, _
        ByVal elementState As DataGridViewElementStates, _
        ByVal value As Object, _
        ByVal formattedValue As Object, _
        ByVal errorText As String, _
        ByVal cellStyle As DataGridViewCellStyle, _
        ByVal advancedBorderStyle As DataGridViewAdvancedBorderStyle, _
        ByVal paintParts As DataGridViewPaintParts)

        ' Call the base class method to paint the default cell appearance.
        MyBase.Paint(graphics, clipBounds, cellBounds, rowIndex, elementState, _
            value, formattedValue, errorText, cellStyle, _
            advancedBorderStyle, paintParts)

        ' Retrieve the client location of the mouse pointer.
        Dim cursorPosition As Point = _
            Me.DataGridView.PointToClient(Cursor.Position)

        ' If the mouse pointer is over the current cell, draw a custom border.
        If cellBounds.Contains(cursorPosition) Then
            Dim newRect As New Rectangle(cellBounds.X + 1, _
                cellBounds.Y + 1, cellBounds.Width - 4, _
                cellBounds.Height - 4)
            graphics.DrawRectangle(Pens.Red, newRect)
        End If

    End Sub

    ' Force the cell to repaint itself when the mouse pointer enters it.
    Protected Overrides Sub OnMouseEnter(ByVal rowIndex As Integer)
        Me.DataGridView.InvalidateCell(Me)
    End Sub

    ' Force the cell to repaint itself when the mouse pointer leaves it.
    Protected Overrides Sub OnMouseLeave(ByVal rowIndex As Integer)
        Me.DataGridView.InvalidateCell(Me)
    End Sub

End Class

Public Class DataGridViewRolloverCellColumn
    Inherits DataGridViewColumn

    Public Sub New()
        Me.CellTemplate = New DataGridViewRolloverCell()
    End Sub

End Class

编译代码

此示例需要：

对 System、System.Windows.Forms 和 System.Drawing 程序集的引用。

另请参阅

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如何扩展行为和外观以自定义 Windows 窗体 DataGridView 控件中的单元格和列

自定义 DataGridView 控件中的单元格和列

示例：

编译代码

另请参阅

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