winform控件开发总结

winform控件开发总结。

1.开发控件tabcontrol.继承自system.windows.controls下面的tabcontrol。重写事件OnPaint

在里面重绘了tab区域。

private void DrawControl(Graphics graphics)
        {
            //外层矩形
            Rectangle tabControlArea = this.ClientRectangle;
           

            //Fill client area
            //Brush brush = new SolidBrush(SystemColors.Control);
            Brush brush = new SolidBrush(Color.White);
            graphics.FillRectangle(brush, tabControlArea);
            //graphics.DrawRectangle(new Pen(Color.DarkRed), tabControlArea);
            brush.Dispose();

            //内层矩形
            Rectangle tabArea = this.DisplayRectangle;
            ////border
            //int nDelta = SystemInformation.BorderSize.Width;
            ////Pen border = new Pen(SystemColors.Highlight);
            //Pen border = new Pen(Color.White);
            //tabArea.Inflate(nDelta, nDelta);
            //graphics.DrawRectangle(border, tabArea);
          
            //clip region for drawing tabs
            Region rSaved = graphics.Clip;
            Rectangle rRec =
                new Rectangle(tabArea.Left, tabControlArea.Top, tabArea.Width, tabControlArea.Height);
            graphics.SetClip(rRec);

            for (int i = 0; i < this.TabCount; i++)
            {
                DrawTab(graphics, this.TabPages[i], i);
            }
            graphics.Clip = rSaved;
        }

        internal void DrawTab(Graphics g, TabPage tabPage, int nIndex)
        {
            Rectangle recBounds = this.GetTabRect(nIndex);
            Rectangle tabMy=new Rectangle(recBounds.X,recBounds.Y,this.Width,recBounds.Height);
            var backSb = new SolidBrush(Color.FromArgb(233,242,246));
            g.FillRectangle(backSb, tabMy);

            RectangleF tabTextArea = (RectangleF)this.GetTabRect(nIndex);

            bool bSelected = (this.SelectedIndex == nIndex);

            Point[] pt = new Point[7];
            if (this.Alignment == TabAlignment.Top)
            {
                pt[0] = new Point(recBounds.Left, recBounds.Bottom);
                pt[1] = new Point(recBounds.Left, recBounds.Top + 3);
                pt[2] = new Point(recBounds.Left + 3, recBounds.Top);
                pt[3] = new Point(recBounds.Right - 3, recBounds.Top);
                pt[4] = new Point(recBounds.Right, recBounds.Top + 3);
                pt[5] = new Point(recBounds.Right, recBounds.Bottom);
                pt[6] = new Point(recBounds.Left, recBounds.Bottom);
            }
            else
            {
                pt[0] = new Point(recBounds.Left, recBounds.Top);
                pt[1] = new Point(recBounds.Right, recBounds.Top);
                pt[2] = new Point(recBounds.Right, recBounds.Bottom - 3);
                pt[3] = new Point(recBounds.Right - 3, recBounds.Bottom);
                pt[4] = new Point(recBounds.Left + 3, recBounds.Bottom);
                pt[5] = new Point(recBounds.Left, recBounds.Bottom - 3);
                pt[6] = new Point(recBounds.Left, recBounds.Top);
            }

            //----------------------------
            // fill this tab with background color
            Brush br = new SolidBrush(Color.Yellow);
            var pageImageNormal = Image.FromFile(@"Resources\rtab_normal.png");
            g.DrawImage(pageImageNormal, recBounds);
            //g.FillPolygon(br, pt);
            br.Dispose();
            //----------------------------

            //----------------------------
            // draw border
            //g.DrawRectangle(SystemPens.ControlDark, recBounds);
            //g.DrawPolygon(SystemPens.ControlDark, pt);
            //var pen3 = new Pen(tabBackColor, 1);
            var pen3 = new Pen(Color.White, 1);
            g.DrawPolygon(pen3,pt);
            pen3.Dispose();

            if (bSelected)
            {
                //----------------------------
                // clear bottom lines
                Pen pen = new Pen(tabPage.BackColor);
                switch (this.Alignment)
                {
                    case TabAlignment.Top:
                        g.DrawLine(pen, recBounds.Left + 1, recBounds.Bottom,
                                        recBounds.Right - 1, recBounds.Bottom);
                        g.DrawLine(pen, recBounds.Left + 1, recBounds.Bottom + 1,
                                        recBounds.Right - 1, recBounds.Bottom + 1);
                        break;

                    case TabAlignment.Bottom:
                        g.DrawLine(pen, recBounds.Left + 1, recBounds.Top,
                                           recBounds.Right - 1, recBounds.Top);
                        g.DrawLine(pen, recBounds.Left + 1, recBounds.Top - 1,
                                           recBounds.Right - 1, recBounds.Top - 1);
                        g.DrawLine(pen, recBounds.Left + 1, recBounds.Top - 2,
                                           recBounds.Right - 1, recBounds.Top - 2);
                        break;
                }
                pen.Dispose();
                //----------------------------
            }
            //----------------------------

            ////----------------------------
            //// draw string
            StringFormat stringFormat = new StringFormat();
            stringFormat.Alignment = StringAlignment.Center;
            stringFormat.LineAlignment = StringAlignment.Center;

            br = new SolidBrush(tabPage.ForeColor);

            g.DrawString(tabPage.Text, Font, br, tabTextArea,
                                                 stringFormat);
            //----------------------------
        }

这个不存在问题。因为一般的时候重绘这个控件都会重写这个部门。添加些自己的见面要求。

但是都不会重绘tabpage。这个就是整个区域中四方形的部分。

如果不重写这个部分。在放置控件的时候就会有些问题。出现一个灰色条形线。

这是因为控件在嵌入的时候不是占用这个控件区域，它会留下一块边区域。

因此，tabpage对象的背景色要和主Penel的背景色一致。

2.TreeView控件的DrawNode事件

        void MyTreeView_DrawNode(object sender, DrawTreeNodeEventArgs e)
        {
            //e.Graphics.SetClip(NodeBounds(e.Node));
            if ((e.State & TreeNodeStates.Selected) != 0)
            {
                Color myColor = Color.FromArgb(135, 223, 250);
                SolidBrush sb = new SolidBrush(myColor);
                e.Graphics.FillRectangle(sb, NodeBounds(e.Node));
                sb.Dispose();

                TreeViewDrawString(sender, e.Node,Brushes.Red);
               
            }
            else
            {
                //e.DrawDefault = true;
                TreeViewDrawString(sender, e.Node, Brushes.Black);
            }

它在点击打开子节点的时候，不会重绘最上边节点。会造成上面部分字体重合显示。该问题一直没找到是什么原因造成的。