要將Winform窗體居中，可以使用以下方法:

1. 使用Screen.PrimaryScreen對象的屬性來獲取主顯示屏的寬度和高度。

int screenWidth = Screen.PrimaryScreen.Bounds.Width;
int screenHeight = Screen.PrimaryScreen.Bounds.Height;

2. 使用Form對象的Width和Height屬性來獲取窗體的寬度和高度。

int formWidth = this.Width;
int formHeight = this.Height;

3. 計算窗體的左上角坐標，并使用Location屬性來設置窗體的位置。

int left = (screenWidth - formWidth) / 2;
int top = (screenHeight - formHeight) / 2;
this.Location = new Point(left, top);

完整的代碼示例:

using System;
using System.Drawing;
using System.Windows.Forms;
namespace CenterForm
{
public partial class MainForm : Form
{
public MainForm()
{
InitializeComponent();
}
private void MainForm_Load(object sender, EventArgs e)
{
CenterForm();
}
private void CenterForm()
{
int screenWidth = Screen.PrimaryScreen.Bounds.Width;
int screenHeight = Screen.PrimaryScreen.Bounds.Height;
int formWidth = this.Width;
int formHeight = this.Height;
int left = (screenWidth - formWidth) / 2;
int top = (screenHeight - formHeight) / 2;
this.Location = new Point(left, top);
}
}
}

在窗體的Load事件中調用CenterForm方法，即可將窗體居中顯示。