添加项目文件。

LargeSquareOne/FrmHelper.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Windows.Forms;
+
+namespace LargeSquareOne
+{
+    public partial class FrmHelper : Form
+    {
+        public FrmHelper()
+        {
+            InitializeComponent();
+        }
+
+        private void btn_Close_Click(object sender, EventArgs e)
+        {
+            this.Close();
+        }
+    }
+}