C# WinForm 自定义控件，DataGridView背景透明，TabControl背景透明

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

namespace RaywindStudio.Components
{

public partial class DataGViewX : DataGridView
{
public DataGViewX()
{
InitializeComponent();
this.SetStyle(ControlStyles.UserPaint, true);//用户自己绘制
this.SetStyle(ControlStyles.ResizeRedraw, true);
this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
this.SetStyle(ControlStyles.OptimizedDoubleBuffer, true);
this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);
}

private System.ComponentModel.IContainer components = null;
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
private void InitializeComponent()
{
components = new System.ComponentModel.Container();
}

[DescriptionAttribute("自定义背景图：当BackTransparent=True时，忽略此设置，直接使用父容器背景")]
[EditorBrowsable(EditorBrowsableState.Always), Browsable(true)]
public Image BackImage { get; set; }

[DescriptionAttribute("背景透明：当True时，直接使用父容器背景。否则使用BackImage填充背景")]
[EditorBrowsable(EditorBrowsableState.Always), Browsable(true)]
public bool BackTransparent { get; set; } = true;

protected override void PaintBackground(Graphics graphics, Rectangle clipBounds, Rectangle gridBounds)
{
base.PaintBackground(graphics, clipBounds, gridBounds);
if(BackTransparent)
BackImage = GetBackImage(this.Parent, this.Left, this.Top, this.Width, this.Height);
if (BackImage != null)
graphics.DrawImage(BackImage, clipBounds);
}

public Bitmap GetBackImage(Control parent, int x, int y, int w, int h)
{
if (parent.BackgroundImage != null)
{
Bitmap bt = new Bitmap(parent.Width, parent.Height);
PictureBox pb = new PictureBox();
pb.Size = parent.Size;
pb.BackgroundImage = parent.BackgroundImage;
pb.BackgroundImageLayout = parent.BackgroundImageLayout;
pb.DrawToBitmap(bt, pb.DisplayRectangle);
pb.Dispose();
Bitmap destBitmap = new Bitmap(w, h);
Graphics g = Graphics.FromImage(destBitmap);
g.DrawImage(bt, new Rectangle(0, 0, w, h), new Rectangle(x, y, w, h), GraphicsUnit.Pixel);
bt.Dispose();
g.Dispose();
return destBitmap;
}
else
return null;
}
}

}