矩形动画闪烁

我正在尝试创建矩形的简单动画。动画是一个非常简单的矩形，初始大小为1 x 400像素，使用计时器每25毫秒增加4像素的宽度。但是动画闪烁，我将Form设置为双缓冲，但它没有帮助。似乎我必须将此属性设置为矩形本身，但在矩形类中没有双重缓冲属性:(。有别的办法吗?或者用完全不同的方法来做这个简单的动画?提前感谢

形式代码:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        animation_timer.Start();
    }
    private void animation_timer_Tick(object sender, EventArgs e)
    {
        rect.Width+=4;
        if (rect.Width > 778)
        {
            animation_timer.Stop();
        }
    }
}

设计师代码:

    private void InitializeComponent()
    {
        this.components = new System.ComponentModel.Container();
        this.shapeContainer1 = new Microsoft.VisualBasic.PowerPacks.ShapeContainer();
        this.rect = new Microsoft.VisualBasic.PowerPacks.RectangleShape();
        this.animation_timer = new System.Windows.Forms.Timer(this.components);
        this.SuspendLayout();
        // 
        // shapeContainer1
        // 
        this.shapeContainer1.Location = new System.Drawing.Point(0, 0);
        this.shapeContainer1.Margin = new System.Windows.Forms.Padding(0);
        this.shapeContainer1.Name = "shapeContainer1";
        this.shapeContainer1.Shapes.AddRange(new   
        Microsoft.VisualBasic.PowerPacks.Shape[] {
        this.rect});
        this.shapeContainer1.Size = new System.Drawing.Size(784, 562);
        this.shapeContainer1.TabIndex = 0;
        this.shapeContainer1.TabStop = false;
        // 
        // rect
        // 
        this.rect.FillColor = System.Drawing.Color.Black;
        this.rect.FillStyle = Microsoft.VisualBasic.PowerPacks.FillStyle.Solid;
        this.rect.Location = new System.Drawing.Point(5, 66);
        this.rect.Name = "rect";
        this.rect.Size = new System.Drawing.Size(1, 400);
        // 
        // animation_timer
        // 
        this.animation_timer.Interval = 25;
        this.animation_timer.Tick += new       
        System.EventHandler(this.animation_timer_Tick);
        // 
        // Form1
        // 
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(784, 562);
        this.Controls.Add(this.shapeContainer1);
        this.DoubleBuffered = true;
        this.Name = "Form1";
        this.Text = "Form1";
        this.ResumeLayout(false);
    }