DataGridViewRowPrePaintEventArgs.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 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 方法在行的可见单元格周围绘制焦点。 代码实际上使用 DataGridViewRowPostPaintEventArgs.DrawFocus 方法，该方法几乎与 的 DataGridViewRowPrePaintEventArgs方法相同DrawFocus。 此示例是如何：自定义 DataGridView 控件中行的外观中提供的更大示例的 Windows 窗体一部分。

// 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 及其单元格的内容时，请使用 方法。 如果手动绘制整行及其单元格的内容，请将 HandledEventArgs.Handled 属性设置为 true。 当 为 true时HandledEventArgs.Handled，CellPainting不会发生 和 RowPostPaint 事件。

另请参阅

• DataGridView
• BackColor
• SelectionBackColor
• DataGridViewRow
• Handled