c# - 从右到左 TabControl c# 的 TabPages 的关闭按钮

Question

我想向 TabControl 的 TabPages 添加一个关闭按钮。我尝试了这段代码，它与从左到右的 TabControl 一起工作正常:

private Point _imageLocation = new Point(13, 5);
private Point _imgHitArea = new Point(13, 2);

this.tabControl2.DrawMode = System.Windows.Forms.TabDrawMode.OwnerDrawFixed;

tabControl2.DrawItem += TabControl2_DrawItem;

private void TabControl2_DrawItem(object sender, System.Windows.Forms.DrawItemEventArgs e)
{
    try
    {
        Image img = new Bitmap(GestionP.Properties.Resources.Close);
        Rectangle r = e.Bounds;
        r = this.tabControl2.GetTabRect(e.Index);
        r.Offset(2, 2);
        Brush TitleBrush = new SolidBrush(Color.Black);
        Font f = this.Font;
        string title = this.tabControl2.TabPages[e.Index].Text;
        e.Graphics.DrawString(title, f, TitleBrush, new PointF(r.X, r.Y));

        if (tabControl2.SelectedIndex >= 1)
        {
            e.Graphics.DrawImage(img, new Point(r.X + (this.tabControl2.GetTabRect(e.Index).Width - _imageLocation.X), _imageLocation.Y));
        }

    }
        catch (Exception) { }
}

    private void tabControl2_MouseClick(object sender, MouseEventArgs e)
    {
        TabControl tc = (TabControl)sender;
        Point p = e.Location;
        int _tabWidth = 0;
        _tabWidth = this.tabControl2.GetTabRect(tc.SelectedIndex).Width - (_imgHitArea.X);
        Rectangle r = this.tabControl2.GetTabRect(tc.SelectedIndex);
        r.Offset(_tabWidth, _imgHitArea.Y);
        r.Width = 16;
        r.Height = 16;
        if (tabControl2.SelectedIndex >= 1)
        {
            if (r.Contains(p))
            {
                TabPage TabP = (TabPage)tc.TabPages[tc.SelectedIndex];
                tc.TabPages.Remove(TabP);

            }
        }
    }

但是当我设置属性 RightToLeftLayout = true 和 RightToLeft = true 它不起作用时，TabPage 标题不会出现并且还有关闭按钮。

那么如何以接受 RightToLeft 属性的方式修复代码？

Answer 1

您可以创建一个函数来将矩形的坐标转换为容器中的 RTL 坐标:

public static Rectangle GetRTLCoordinates(Rectangle container, Rectangle drawRectangle)
{
    return new Rectangle(
        container.Width - drawRectangle.Width - drawRectangle.X,
        drawRectangle.Y,
        drawRectangle.Width,
        drawRectangle.Height);
}

而在 RTL 模式下绘画时，以这种方式计算坐标:

tabRect = GetRTLCoordinates(this.tabControl2.ClientRectangle, tabRect);

此外，您还应该使用 StringFormat 绘制字符串，并在处于 RTL 模式时将其设置为使用 StringFormatFlags.DirectionRightToLeft，并使用字符串在转换后的矩形中绘制字符串格式:

e.Graphics.DrawString(this.tabControl2.TabPages[e.Index].Text, 
                      this.Font, Brushes.Black, tabRect, sf);

您可以将所有代码封装在继承TabControl的CustomTabControl中。

截图

整个代码可以是:

我想您在某个地方有一个关闭图像，例如 Properties.Default.Close 并将其分配给 this.CloseImage。这是我使用的图像:

我还设置了 this.tabControl2.Padding = new Point(10, 3); 以提供额外的可用空间来绘制图像。

您也可以简单地添加不关闭第一个选项卡的条件。

Image CloseImage;

private void Form1_Load(object sender, EventArgs e)
{
    this.tabControl2.DrawMode = System.Windows.Forms.TabDrawMode.OwnerDrawFixed;
    tabControl2.DrawItem += TabControl2_DrawItem;
    tabControl2.MouseClick += tabControl2_MouseClick;
    CloseImage = Properties.Resources.Close;
    this.tabControl2.Padding = new Point(10, 3);
}


private void TabControl2_DrawItem(object sender, 
                                  System.Windows.Forms.DrawItemEventArgs e)
{
    try
    {
        var tabRect = this.tabControl2.GetTabRect(e.Index);
        tabRect.Inflate(-2, -2);
        var imageRect = new Rectangle(tabRect.Right - CloseImage.Width,
                                 tabRect.Top + (tabRect.Height - CloseImage.Height) / 2,
                                 CloseImage.Width,
                                 CloseImage.Height);

        var sf = new StringFormat(StringFormat.GenericDefault);
        if (this.tabControl2.RightToLeft == System.Windows.Forms.RightToLeft.Yes &&
            this.tabControl2.RightToLeftLayout == true)
        {
            tabRect = GetRTLCoordinates(this.tabControl2.ClientRectangle, tabRect);
            imageRect = GetRTLCoordinates(this.tabControl2.ClientRectangle, imageRect);
            sf.FormatFlags |= StringFormatFlags.DirectionRightToLeft;
        }

        e.Graphics.DrawString(this.tabControl2.TabPages[e.Index].Text,
                              this.Font, Brushes.Black, tabRect, sf);
        e.Graphics.DrawImage(CloseImage, imageRect.Location);

    }
    catch (Exception) { }
}

private void tabControl2_MouseClick(object sender, MouseEventArgs e)
{

    for (var i = 0; i < this.tabControl2.TabPages.Count; i++)
    {
        var tabRect = this.tabControl2.GetTabRect(i);
        tabRect.Inflate(-2, -2);
        var imageRect = new Rectangle(tabRect.Right - CloseImage.Width,
                                 tabRect.Top + (tabRect.Height - CloseImage.Height) / 2,
                                 CloseImage.Width,
                                 CloseImage.Height);
        if (imageRect.Contains(e.Location))
        {
            this.tabControl2.TabPages.RemoveAt(i);
            break;
        }
    }
}

public static Rectangle GetRTLCoordinates(Rectangle container, Rectangle drawRectangle)
{
    return new Rectangle(
        container.Width - drawRectangle.Width - drawRectangle.X,
        drawRectangle.Y,
        drawRectangle.Width,
        drawRectangle.Height);
}