用DataGridViewComboBoxColumn显示DataGridView中的选定图像？

我在使用DataGridView和DataGridViewComboBoxColumn让用户从图像列表中选择图像时遇到问题。在标题为“DatagridViewComboBoxColumn的自定义绘制”ref Link的问题中进行讨论。我也遇到了这个问题，因为只有当单元格处于编辑模式时才会绘制图像。当我点击组合框外的某个地方时，所选图像将消失！我已经实现了CellPainting事件来重绘图像，但仍然无法解决问题。我测试DataGridViewComboBoxColumn用以下代码：用DataGridViewComboBoxColumn显示DataGridView中的选定图像？

public Form1() 
    { 
     InitializeComponent(); 
     ..... 
     imageList.Images.Add(Properties.Resources.icon_priority_low); 
     imageList.Images.Add(Properties.Resources.icon_priority_medium); 
     ..... 
    } 

    private void Form1_Load(object sender, EventArgs e) 
    { 
     .....    
     DataGridViewComboBoxCell dgvcbc = (DataGridViewComboBoxCell)newDataGridView1.Rows[0].Cells[1]; 
     dgvcbc.Items.Add("test0"); 
     dgvcbc.Items.Add("test1"); 
     .....   
    } 

    private void newDataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e) 
    { 
     if (e.Control is ComboBox) 
     { 
      ComboBox theCB = (ComboBox)e.Control; 
      theCB.DrawMode = DrawMode.OwnerDrawFixed; 
      try 
      { 
       theCB.DrawItem -= combobox1_DrawItem; 
      } 
      catch { } 
      theCB.DrawItem += combobox1_DrawItem; 
     } 
    } 

    private void combobox1_DrawItem(object sender, DrawItemEventArgs e) 
    { 
     Graphics g = e.Graphics; 
     Brush br = SystemBrushes.WindowText; 
     Brush brBack; 
     Rectangle rDraw; 
     bool bSelected = e.State == DrawItemState.Selected; 
     bool bValue = e.State == DrawItemState.ComboBoxEdit; 

     if ((e.Index < 0) || (columnIndex != 1)) 
      return; 

     rDraw = e.Bounds; 
     rDraw.Inflate(-1, -1); 

     int x, y; 

     x = e.Bounds.Left + 25; 
     y = e.Bounds.Top + 1; 
     int midX = (int)(e.Bounds.Width/2) + e.Bounds.Left; 

     // Show image and ignore text. 
     g.DrawImage(imageList.Images[e.Index], new Rectangle(midX - 6, y + 2, 12, 12));      
    } 

    private void newDataGridView1_CellPainting(object sender, DataGridViewCellPaintingEventArgs e) 
    { 
     if (columnIndex != 1) 
      return; 

     Graphics g = e.Graphics; 
     Rectangle rDraw = newDataGridView1.GetCellDisplayRectangle(columnIndex, rowIndex, true); 

     e.PaintBackground(e.ClipBounds, true); 
     e.PaintContent(e.ClipBounds); 

     using (Brush backColorBrush = new SolidBrush(e.CellStyle.BackColor)) 
     { 
      int y = rDraw.Y + 1; 
      int midX = (int)(rDraw.Width/2) + rDraw.X; 

      g.DrawImage(imageList.Images[0], new Rectangle(midX - 6, y + 2, 12, 12)); 

      e.PaintContent(e.ClipBounds); 
      e.Handled = true; 
     } 
    } 
}

细胞将显示，而不是图片[0]“TEST0”如果我点击的DataGridView的其它细胞。请你帮忙解决这个问题。非常感谢。

来源

2012-02-15 user1133555

最后致电PaintContent()会擦除您绘制的图像。

绘制图像之前，您必须绘制单元格（但不包括前景）。它看起来像这样：

private void newDataGridView1_CellPainting(object sender, DataGridViewCellPaintingEventArgs e) 
{ 
    if (columnIndex != 1) 
     return; 

    Graphics g = e.Graphics; 
    Rectangle rDraw = newDataGridView1.GetCellDisplayRectangle(columnIndex, rowIndex, true); 

    e.Paint(e.CellBounds, e.PaintParts & ~DataGridViewPaintParts.ContentForeground); 

    int y = rDraw.Y + 1; 
    int midX = (int)(rDraw.Width/2) + rDraw.X; 

    g.DrawImage(imageList.Images[0], new Rectangle(midX - 6, y + 2, 12, 12)); 

    e.Handled = true; 
}

来源

2015-08-31 08:39:31 Bioukh

用DataGridViewComboBoxColumn显示DataGridView中的选定图像？

回答

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