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

 注意: 以下代码，属性直接赋值的语法糖要vs2015以上才支持。

 

using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
namespace RaywindStudio.Components
{
    public class TabCtrlX : TabControl
    {
        public TabCtrlX()
        {
            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);
            //让控件支持透明色
            this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);
        }

        #region designer
        /// <summary>
        /// 必需的设计器变量。
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary> 
        /// 清理所有正在使用的资源。
        /// </summary>
        /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region 组件设计器生成的代码

        /// <summary>
        /// 设计器支持所需的方法 - 不要
        /// 使用代码编辑器修改此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {
            components = new System.ComponentModel.Container();
        }

        #endregion
        #endregion
        //[EditorBrowsable(EditorBrowsableState.Always), Browsable(true)]
        public override Color BackColor {
            get {
                return Color.FromArgb(Alpha, BgColor);
            }
            set {
                Alpha = BackColor.A;
                BgColor = BackColor;
            }
        }

        [DisplayName("Color.Alpha")]
        [CategoryAttribute("Color"), DescriptionAttribute("Opacity不透明度0--255")]
        [EditorBrowsable(EditorBrowsableState.Always), Browsable(true)]
        public byte Alpha { get; set; } = 16;

        [DisplayName("Color.BgColor")]
        [CategoryAttribute("Color"), DescriptionAttribute("TabControl工作区背景色")]
        [EditorBrowsable(EditorBrowsableState.Always), Browsable(true)]
        public Color BgColor { get; set; } = Color.White;

        [DisplayName("Color.BordColor")]
        [CategoryAttribute("Color"), DescriptionAttribute("TabControl边线颜色")]
        [EditorBrowsable(EditorBrowsableState.Always), Browsable(true)]
        public Color BordColor { get; set; } = Color.LightGray;

        [DisplayName("Color.TitleColor")]
        [CategoryAttribute("Color"), DescriptionAttribute("TabPage标头背景色")]
        [EditorBrowsable(EditorBrowsableState.Always), Browsable(true)]
        public Color TitleColor { get; set; } = Color.WhiteSmoke;

        [DisplayName("Color.TitleSeleColor")]
        [CategoryAttribute("Color"), DescriptionAttribute("TabPage标头选中背景色")]
        [EditorBrowsable(EditorBrowsableState.Always), Browsable(true)]
        public Color TitleSeleColor { get; set; } = Color.White;

        [DisplayName("Color.TextColor")]
        [CategoryAttribute("Color"), DescriptionAttribute("TabPage标题颜色")]
        [EditorBrowsable(EditorBrowsableState.Always), Browsable(true)]
        public Color TextColor { get; set; } = Color.Gray;

        [DisplayName("Color.TextSeleColor")]
        [CategoryAttribute("Color"), DescriptionAttribute("TabPage选中标题颜色")]
        [EditorBrowsable(EditorBrowsableState.Always), Browsable(true)]
        public Color TextSeleColor { get; set; } = Color.Black;

        protected override void OnPaint(PaintEventArgs e)
        {
            this.DrawTitle(e.Graphics);
            base.OnPaint(e);
            DrawBorder(e.Graphics);
        }

        protected void DrawBorder(Graphics g)
        {
            g.DrawRectangle(new Pen(BordColor, 1F), ClientRectangle);
        }

        protected void DrawTitle(Graphics g)
        {
            StringFormat sf = new StringFormat();
            sf.Alignment = StringAlignment.Center;
            sf.LineAlignment = StringAlignment.Center;
            using (SolidBrush sb = new SolidBrush(SystemColors.Control))
            {
                for (int i = 0; i < this.TabPages.Count; i++)
                {
                    Rectangle rect = this.GetTabRect(i);
                    if (this.SelectedIndex == i)
                    {
                        sb.Color = TitleSeleColor;
                        g.FillRectangle(sb, rect);
                        g.DrawString(this.TabPages[i].Text, this.Font, new SolidBrush(TextSeleColor), rect, sf);
                    }
                    else
                    {
                        sb.Color = TitleColor;
                        g.FillRectangle(sb, rect);
                        g.DrawString(this.TabPages[i].Text, this.Font, new SolidBrush(TextColor), rect, sf);
                    }
                }
            }
        }
    }
}

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;
        }
    }

}