添加项目文件。

C-Windows-1/Form4.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Windows.Forms;
+
+namespace C_Windows_1
+{
+    public partial class Form4 : Form
+    {
+        public Form4()
+        {
+            InitializeComponent();
+        }
+
+        private void Form4_Load(object sender, EventArgs e)
+        {
+
+        }
+    }
+}