c#多个窗体时，点击按钮，一次关闭所有窗体

class1.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WindowsFormsApplication3
{
public static class Class1
{
public static Form1 bridegeOfForm1;//为什么这个字段的类型是form1呢？主窗体！
}
}

program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication3
{
static class Program
{
/// <summary>
/// 应用程序的主入口点。
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());//有这行代码可以看出，form1是主窗体
}
}
}

Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication3
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{
Class1.bridegeOfForm1 = this;
}

private void button1_Click(object sender, EventArgs e)
{
Form2 frm2 = new Form2();
frm2.Show();
}
}
}

form2.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication3
{
public partial class Form2 : Form
{
public Form2()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
Class1.bridegeOfForm1.Close();
}
}
}
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作者：心少朴
来源：CSDN
原文：https://blog.csdn.net/yushaopu/article/details/52561522