如何让父窗体知道子窗体已关闭

在实例化子窗体时,为主/父窗体添加侦听器事件。下面的例子:

    private void button1_Click(object sender, EventArgs e)
    {
        Form2 f2 = new Form2();
        f2.CustomFormClosed += CloseListener;
        f2.Show();
    }

    private void CloseListener(object sender, EventArgs e, string test)
    {
        Console.WriteLine(test);
    }

为自定义委托和事件编辑

格式2代码:

    public delegate void CustomFormClosedHandler(object semder, FormClosedEventArgs e, string text);
    public event CustomFormClosedHandler CustomFormClosed;

    private void Form2_FormClosed(object sender, FormClosedEventArgs e)
    {
        CustomFormClosed(sender, e, "Hello World!");
    }

一种方法是:

返回 DialogResult 从 FormClosing 的事件处理程序 Form2

private void Form2_FormClosing(object sender, FormClosingEventArgs e)
{
    this.DialogResult = DialogResult.OK;
}

运行模态 ShowDialog() 在新线程上 Form1 然后等待 对话结果

private void button2_Click(object sender, EventArgs e)
{
    Form2 f2 = new Form2();
    System.Threading.Tasks.Task.Run(() =>
    {
        if (f2.ShowDialog() == DialogResult.OK)
        {
            // do here whatever you want to do
            MessageBox.Show("Form2 closed");
        }
    });
}

你所要做的就是:

1:在父窗体中添加公共静态方法:

public static void ChildFromClosed()
    {
        //Inform here
        MessageBox.Show("Child form is closed!");
    }

2:在子窗体中添加从父窗体调用该方法的(FormClosed)事件:

private void frmChild_FormClosed(object sender, FormClosedEventArgs e)
    {
        //calling the static method in Parents form
        frmParent.ChildFromClosed();
    }