DataGridViewRowPostPaintEventArgs.DrawFocus(Rectangle, Boolean) 方法

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

围绕指定的边界绘制聚焦框。

public:
 void DrawFocus(System::Drawing::Rectangle bounds, bool cellsPaintSelectionBackground);

public void DrawFocus (System.Drawing.Rectangle bounds, bool cellsPaintSelectionBackground);

member this.DrawFocus : System.Drawing.Rectangle * bool -> unit

Public Sub DrawFocus (bounds As Rectangle, cellsPaintSelectionBackground As Boolean)

参数

bounds

Rectangle

一个指定聚焦区域的 Rectangle。

cellsPaintSelectionBackground

Boolean

若为 true，则使用 SelectionBackColor 属性的 InheritedStyle 属性确定聚焦框的颜色；若为 false，则使用 BackColor 属性的 InheritedStyle 属性。

例外

InvalidOperationException

RowIndex 小于零或大于将 DataGridView 控件中的行数减一得到的值。

示例

下面的代码示例演示如何使用 DrawFocus 该方法在行的可见单元格周围绘制焦点。 此示例是“如何：自定义 Windows 窗体 DataGridView 控件中行的外观”中提供的大型示例的一部分。

// Paints the content that spans multiple columns and the focus rectangle.
void dataGridView1_RowPostPaint(object sender,
    DataGridViewRowPostPaintEventArgs e)
{
    // Calculate the bounds of the row.
    Rectangle rowBounds = new Rectangle(
        this.dataGridView1.RowHeadersWidth, e.RowBounds.Top,
        this.dataGridView1.Columns.GetColumnsWidth(
            DataGridViewElementStates.Visible) -
        this.dataGridView1.HorizontalScrollingOffset + 1,
        e.RowBounds.Height);

    SolidBrush forebrush = null;
    try
    {
        // Determine the foreground color.
        if ((e.State & DataGridViewElementStates.Selected) ==
            DataGridViewElementStates.Selected)
        {
            forebrush = new SolidBrush(e.InheritedRowStyle.SelectionForeColor);
        }
        else
        {
            forebrush = new SolidBrush(e.InheritedRowStyle.ForeColor);
        }

        // Get the content that spans multiple columns.
        object recipe =
            this.dataGridView1.Rows.SharedRow(e.RowIndex).Cells[2].Value;

        if (recipe != null)
        {
            String text = recipe.ToString();

            // Calculate the bounds for the content that spans multiple 
            // columns, adjusting for the horizontal scrolling position 
            // and the current row height, and displaying only whole
            // lines of text.
            Rectangle textArea = rowBounds;
            textArea.X -= this.dataGridView1.HorizontalScrollingOffset;
            textArea.Width += this.dataGridView1.HorizontalScrollingOffset;
            textArea.Y += rowBounds.Height - e.InheritedRowStyle.Padding.Bottom;
            textArea.Height -= rowBounds.Height -
                e.InheritedRowStyle.Padding.Bottom;
            textArea.Height = (textArea.Height / e.InheritedRowStyle.Font.Height) *
                e.InheritedRowStyle.Font.Height;

            // Calculate the portion of the text area that needs painting.
            RectangleF clip = textArea;
            clip.Width -= this.dataGridView1.RowHeadersWidth + 1 - clip.X;
            clip.X = this.dataGridView1.RowHeadersWidth + 1;
            RectangleF oldClip = e.Graphics.ClipBounds;
            e.Graphics.SetClip(clip);

            // Draw the content that spans multiple columns.
            e.Graphics.DrawString(
                text, e.InheritedRowStyle.Font, forebrush, textArea);

            e.Graphics.SetClip(oldClip);
        }
    }
    finally
    {
        forebrush.Dispose();
    }

    if (this.dataGridView1.CurrentCellAddress.Y == e.RowIndex)
    {
        // Paint the focus rectangle.
        e.DrawFocus(rowBounds, true);
    }
}

' Paints the content that spans multiple columns and the focus rectangle.
Sub dataGridView1_RowPostPaint(ByVal sender As Object, _
    ByVal e As DataGridViewRowPostPaintEventArgs) _
    Handles dataGridView1.RowPostPaint

    ' Calculate the bounds of the row.
    Dim rowBounds As New Rectangle(Me.dataGridView1.RowHeadersWidth, _
        e.RowBounds.Top, Me.dataGridView1.Columns.GetColumnsWidth( _
        DataGridViewElementStates.Visible) - _
        Me.dataGridView1.HorizontalScrollingOffset + 1, e.RowBounds.Height)

    Dim forebrush As SolidBrush = Nothing
    Try
        ' Determine the foreground color.
        If (e.State And DataGridViewElementStates.Selected) = _
            DataGridViewElementStates.Selected Then

            forebrush = New SolidBrush(e.InheritedRowStyle.SelectionForeColor)
        Else
            forebrush = New SolidBrush(e.InheritedRowStyle.ForeColor)
        End If

        ' Get the content that spans multiple columns.
        Dim recipe As Object = _
            Me.dataGridView1.Rows.SharedRow(e.RowIndex).Cells(2).Value

        If (recipe IsNot Nothing) Then
            Dim text As String = recipe.ToString()

            ' Calculate the bounds for the content that spans multiple 
            ' columns, adjusting for the horizontal scrolling position 
            ' and the current row height, and displaying only whole
            ' lines of text.
            Dim textArea As Rectangle = rowBounds
            textArea.X -= Me.dataGridView1.HorizontalScrollingOffset
            textArea.Width += Me.dataGridView1.HorizontalScrollingOffset
            textArea.Y += rowBounds.Height - e.InheritedRowStyle.Padding.Bottom
            textArea.Height -= rowBounds.Height - e.InheritedRowStyle.Padding.Bottom
            textArea.Height = (textArea.Height \ e.InheritedRowStyle.Font.Height) * _
                e.InheritedRowStyle.Font.Height

            ' Calculate the portion of the text area that needs painting.
            Dim clip As RectangleF = textArea
            clip.Width -= Me.dataGridView1.RowHeadersWidth + 1 - clip.X
            clip.X = Me.dataGridView1.RowHeadersWidth + 1
            Dim oldClip As RectangleF = e.Graphics.ClipBounds
            e.Graphics.SetClip(clip)

            ' Draw the content that spans multiple columns.
            e.Graphics.DrawString(text, e.InheritedRowStyle.Font, forebrush, _
                textArea)

            e.Graphics.SetClip(oldClip)
        End If
    Finally
        forebrush.Dispose()
    End Try

    If Me.dataGridView1.CurrentCellAddress.Y = e.RowIndex Then
        ' Paint the focus rectangle.
        e.DrawFocus(rowBounds, True)
    End If

End Sub

注解

DrawFocus自行绘制DataGridViewRow单元格内容及其内容时，请使用该方法。

另请参阅

• DataGridView
• BackColor
• SelectionBackColor
• DataGridViewRow