要在C#中繪制鼠標，可以使用System.Windows.Forms命名空間中的Mouse類。以下是一個簡單的示例代碼：

using System;
using System.Drawing;
using System.Windows.Forms;
public class MouseDrawingForm : Form
{
public MouseDrawingForm()
{
InitializeComponent();
this.DoubleBuffered = true;
}
private void InitializeComponent()
{
this.SuspendLayout();
this.ClientSize = new Size(800, 600);
this.Name = "MouseDrawingForm";
this.Text = "Mouse Drawing";
this.Paint += new PaintEventHandler(MouseDrawingForm_Paint);
this.ResumeLayout(false);
}
private void MouseDrawingForm_Paint(object sender, PaintEventArgs e)
{
// 獲取鼠標當前位置
Point mousePosition = this.PointToClient(Cursor.Position);
// 繪制鼠標
Graphics g = e.Graphics;
Pen pen = new Pen(Color.Red, 2);
g.DrawLine(pen, mousePosition.X - 10, mousePosition.Y, mousePosition.X + 10, mousePosition.Y);
g.DrawLine(pen, mousePosition.X, mousePosition.Y - 10, mousePosition.X, mousePosition.Y + 10);
}
[STAThread]
public static void Main()
{
Application.EnableVisualStyles();
Application.Run(new MouseDrawingForm());
}
}

這段代碼創建了一個繼承自Form的自定義窗體MouseDrawingForm。在窗體的Paint事件處理程序中，獲取鼠標當前位置，并使用Graphics類的DrawLine方法繪制一個十字形的鼠標圖標。最后，通過Application.Run方法運行窗體。運行代碼后，將會顯示一個窗體，鼠標的十字形圖標將會隨著鼠標的移動而更新。