C# 绘制图形时遇到的问题

我在简单的表单上绘制图形时遇到问题。我的代码编译并运行，但预期的红色框不会显示

我正在Visual Studio 2010中使用完整的.NET Framework 4

出了什么问题，如何解决

private void Form1_Load(object sender, EventArgs e)
{
    System.Drawing.Graphics graphicsObj;
    graphicsObj = this.CreateGraphics();
    Pen myPen = new Pen(System.Drawing.Color.Red, 5);
    Rectangle myRectangle = new Rectangle(20, 20, 250, 200);
    graphicsObj.DrawRectangle(myPen, myRectangle);
}

编辑：工作但代码速度慢

    void BatteryPaint(object sender, EventArgs e)
    {
        TabPage page = (TabPage)sender;
        if (!controlsSetup)
        {
            populateBatteryTab(page);
            controlsSetup = true;
        }
        //Create the items
        Rectangle busBar = new Rectangle();
        Rectangle batPack = new Rectangle();
        Rectangle pack1Outline = new Rectangle();
        Rectangle pack2Outline = new Rectangle();
        Rectangle pack3Outline = new Rectangle();
        Rectangle pack4Outline = new Rectangle();

        Color GreenZone = Color.FromArgb(150, 0, 255, 0);
        Color YellowZone = Color.FromArgb(150, 255, 255, 0);
        Color RedZone = Color.FromArgb(150, 255, 0, 0);
        Color greyZone = Color.FromArgb(200, 200, 200, 200);

        Graphics graphicControl = page.CreateGraphics();

        SolidBrush busBarBrush = new SolidBrush(Color.Peru);
        SolidBrush GreenBrush = new SolidBrush(GreenZone);
        SolidBrush GreyBrush = new SolidBrush(greyZone);

        Pen packPen = new Pen(Color.LightGray, (float)8);


        Point busBarTop = new Point(page.Width / 64, page.Height / 32);
        Point busBarBottom = new Point(busBarTop.X, busBarTop.Y + page.Height / 6);

        //change the properties
        //Bus Bar Top
        busBar.Width = page.Width*153 / 640;
        busBar.Height = page.Height / 64;
        busBar.Location = busBarTop;
        graphicControl.FillRectangle(busBarBrush, busBar);

        //Bus Bar Bottom
        busBar.Location = busBarBottom;
        graphicControl.FillRectangle(busBarBrush, busBar);



        //Pack 1
        batPack.Width = page.Width / 20;
        batPack.Height = (busBarBottom.Y + busBar.Height) - busBarTop.Y;
        batPack.Location = new Point(busBarTop.X + page.Width / packSpacingMultiplier, busBarTop.Y);
        pack1Outline.Width = batOutlineWidth;
        graphicControl.FillRectangle(GreenBrush, batPack);
        pack1Outline.Height = (3 * (Battery.Width + page.Width / batSpacingMultiplier) + page.Width / batSpacingMultiplier);
        pack1Outline.Location = new Point(BatPack1.X - (page.Width / batSpacingMultiplier), BatPack1.Y - (page.Width / batSpacingMultiplier));
        for(int numBats = 0; numBats < 30; numBats++)
        {
            Battery.Location = new Point(BatPack1.X + ((numBats % 10) * (Battery.Width + page.Width / batSpacingMultiplier)), BatPack1.Y + ((numBats / 10) * (Battery.Width + page.Width / batSpacingMultiplier)));
            graphicControl.FillEllipse(new SolidBrush(BatteryZone(0.00)), Battery);
        }

        //Pack 2
        batPack.Location = new Point(batPack.Location.X + batPack.Width + page.Width / packSpacingMultiplier, batPack.Location.Y);
        graphicControl.FillRectangle(GreenBrush, batPack);
        pack2Outline.Width = batOutlineWidth;
        pack2Outline.Height = (3 * (Battery.Width + page.Width / batSpacingMultiplier) + page.Width / batSpacingMultiplier);
        pack2Outline.Location = new Point(BatPack2.X - (page.Width / batSpacingMultiplier), BatPack2.Y - (page.Width / batSpacingMultiplier));
        for(int numBats = 0; numBats < 30; numBats++)
        {
            Battery.Location = new Point(BatPack2.X + ((numBats % 10) * (Battery.Width + page.Width / batSpacingMultiplier)), BatPack2.Y + ((numBats / 10) * (Battery.Width + page.Width / batSpacingMultiplier)));
            graphicControl.FillEllipse(new SolidBrush(BatteryZone(0.00)), Battery);
        }

        //Pack 3
        batPack.Location = new Point(batPack.Location.X + batPack.Width + page.Width / packSpacingMultiplier, batPack.Location.Y);
        graphicControl.FillRectangle(GreenBrush, batPack);
        pack3Outline.Width = batOutlineWidth;
        pack3Outline.Height = (3 * (Battery.Width + page.Width / batSpacingMultiplier) + page.Width / batSpacingMultiplier);
        pack3Outline.Location = new Point(BatPack3.X - (page.Width / batSpacingMultiplier), BatPack3.Y - (page.Width / batSpacingMultiplier));
        for(int numBats = 0; numBats < 30; numBats++)
        {
            Battery.Location = new Point(BatPack3.X + ((numBats % 10) * (Battery.Width + page.Width / batSpacingMultiplier)), BatPack3.Y + ((numBats / 10) * (Battery.Width + page.Width / batSpacingMultiplier)));
            graphicControl.FillEllipse(new SolidBrush(BatteryZone(0.00)), Battery);
        }

        //Pack 4
        batPack.Location = new Point(batPack.Location.X + batPack.Width + page.Width / packSpacingMultiplier, batPack.Location.Y);
        graphicControl.FillRectangle(GreyBrush, batPack);
        pack4Outline.Width = batOutlineWidth;
        pack4Outline.Height = (3 * (Battery.Width + page.Width / batSpacingMultiplier) + page.Width / batSpacingMultiplier);
        pack4Outline.Location = new Point(BatPack4.X - (page.Width / batSpacingMultiplier), BatPack4.Y - (page.Width / batSpacingMultiplier));
        for(int numBats = 0; numBats < 30; numBats++)
        {
            Battery.Location = new Point(BatPack4.X + ((numBats % 10) * (Battery.Width + page.Width / batSpacingMultiplier)), BatPack4.Y + ((numBats / 10) * (Battery.Width + page.Width / batSpacingMultiplier)));
            graphicControl.FillEllipse(new SolidBrush(BatteryZone(0.00)), Battery);
        }


        //add the controls
        graphicControl.DrawRectangle(packPen, pack1Outline);
        graphicControl.DrawRectangle(packPen, pack2Outline);
        graphicControl.DrawRectangle(packPen, pack3Outline);
        graphicControl.DrawRectangle(packPen, pack4Outline);
    }

void BatteryPaint（对象发送方，事件参数e）
{
TabPage=（TabPage）发送方；
如果（！controlsSetup）
{
populateBatteryTab（第页）；
controlsSetup=true；
}
//创建项目
矩形母线=新矩形（）；
矩形电池组=新矩形（）；
矩形pack1Outline=新矩形（）；
矩形pack2Outline=新矩形（）；
矩形pack3Outline=新矩形（）；
矩形pack4Outline=新矩形（）；
颜色绿区=Color.FromArgb（150,0,255,0）；
Color YellowZone=Color.FromArgb（150,255,255,0）；
Color RedZone=Color.FromArgb（150,255,0,0）；
Color greyZone=Color.FromArgb（200200200200200）；
Graphics Graphics Control=page.CreateGraphics（）；
SolidBrush busBarBrush=新的SolidBrush（颜色：秘鲁）；
SolidBrush绿刷=新的SolidBrush（绿区）；
SolidBrush灰刷=新的SolidBrush（灰刷）；
钢笔包装纸=新钢笔（颜色为浅灰色，（浮动）8）；
点busBarTop=新点（第页宽度/64，第页高度/32）；
点busBarBottom=新点（busBarTop.X，busBarTop.Y+页面高度/6）；
//更改属性
//母线顶部
母线宽度=页宽*153/640；
母线高度=第页高度/64；
母线位置=母线端；
图形控制。填充矩形（母线槽、母线）；
//母线底部
母线位置=母线槽；
图形控制。填充矩形（母线槽、母线）；
//包1
蝙蝠包宽度=页宽/20；
蝙蝠包高度=（busBarBottom.Y+Bush.Height）-busBarTop.Y；
batPack.Location=新点（busBarTop.X+page.Width/packPacking乘数，busBarTop.Y）；
pack1Outline.Width=batOutlineWidth；
graphicControl.FillRectangle（绿色画笔、蝙蝠包）；
pack1轮廓高度=（3*（Battery.Width+page.Width/batSpacingMultiplier）+page.Width/batSpacingMultiplier）；
pack1 outline.Location=新点（BatPack1.X-（page.Width/batSpacingMultiplier），BatPack1.Y-（page.Width/batSpacingMultiplier））；
用于（int numBats=0；numBats<30；numBats++）
{
Battery.Location=新点（BatPack1.X+（（numBats%10）*（Battery.Width+page.Width/batSpacingMultiplier）），BatPack1.Y+（（numBats/10）*（Battery.Width+page.Width/batSpacingMultiplier））；
graphicControl.FillEllipse（新的SolidBrush（BatteryOne（0.00）），电池）；
}
//包2
batPack.Location=新点（batPack.Location.X+batPack.Width+page.Width/packPacking乘数，batPack.Location.Y）；
graphicControl.FillRectangle（绿色画笔、蝙蝠包）；
pack2Outline.Width=batOutlineWidth；
pack2Outline.Height=（3*（Battery.Width+page.Width/batSpacingMultiplier）+page.Width/batSpacingMultiplier）；
pack2 outline.Location=新点（BatPack2.X-（page.Width/batSpacingMultiplier），BatPack2.Y-（page.Width/batSpacingMultiplier））；
用于（int numBats=0；numBats<30；numBats++）
{
Battery.Location=新点（BatPack2.X+（（numBats%10）*（baterty.Width+page.Width/batSpacingMultiplier）），BatPack2.Y+（（numBats/10）*（baterty.Width+page.Width/batSpacingMultiplier））；
graphicControl.FillEllipse（新的SolidBrush（BatteryOne（0.00）），电池）；
}
//包3
batPack.Location=新点（batPack.Location.X+batPack.Width+page.Width/packPacking乘数，batPack.Location.Y）；
graphicControl.FillRectangle（绿色画笔、蝙蝠包）；
pack3Outline.Width=batOutlineWidth；
pack3轮廓高度=（3*（Battery.Width+page.Width/batSpacingMultiplier）+page.Width/batSpacingMultiplier）；
pack3 outline.Location=新点（BatPack3.X-（page.Width/batSpacingMultiplier），BatPack3.Y-（page.Width/batSpacingMultiplier））；
用于（int numBats=0；numBats<30；numBats++）
{
Battery.Location=新点（BatPack3.X+（（numBats%10）*（Battery.Width+page.Width/batSpacingMultiplier）），BatPack3.Y+（（numBats/10）*（Battery.Width+page.Width/batSpacingMultiplier））；
graphicControl.FillEllipse（新的SolidBrush（BatteryOne（0.00）），电池）；
}
//包4
batPack.Location=新点（batPack.Location.X+batPack.Width+page.Width/packPacking乘数，batPack.Location.Y）；
graphicControl.FillRectangle（灰褐色、蝙蝠包）；
pack4Outline.Width=batOutlineWidth；
pack4轮廓高度=（3*（Battery.Width+page.Width/batSpacingMultiplier）+page.Width/batSpacingMultiplier）；
pack4Outline.Location=新点（BatPack4.X-（page.Width/batSpacingMultiplier），BatPack4.Y-（page.Width/batSpacingMultiplier））；
用于（int numBats=0；numBats<30；numBats++）
{
Battery.Location=新点（BatPack4.X+（（numBats%10）*（baterty.Width+page.Width/batSpacingMultiplier）），BatPack4.Y+（（numBats/10）*（baterty.Width+page.Width/batSpacingMultiplier））；
graphicControl.FillEllipse（新的SolidBrush（BatteryOne（0.00）），电池）；
}
//添加控件
graphicControl.DrawRectangle（包装箱、包装箱轮廓）；
graphicControl.DrawRectangle（packPen、pack2Outline）；
graphicControl.DrawRectangle（packPen、pack3Outline）；
graphicControl.DrawRectangle（packPen、pack4Outline）；
}

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事件中进行绘图，该事件甚至在表单第一次显示之前触发。窗户正在重新粉刷

private void Form1_Paint(object sender, PaintEventArgs e)
{
    System.Drawing.Graphics graphicsObj = e.Graphics;
    Pen myPen = new Pen(System.Drawing.Color.Red, 5);
    Rectangle myRectangle = new Rectangle(20, 20, 250, 200);
    graphicsObj.DrawRectangle(myPen, myRectangle);
}

protected override void OnPaint(PaintEventArgs e)
{
    Graphics g = e.Graphics;
    Pen myPen = new Pen(Color.Red, 5);
    g.DrawRectangle(myPen, 20, 20, 250, 200);
}