c# - 在第二个表格关闭时制作一个事件

Question

假设我有两种形式

1st form name is : Form1

Consists from : 1 Button and it's name is Button1

这个按钮是 Public 从它的 properties 并且有一个 OnClick 事件

事件是:

        private void Button1_Click(object sender, EventArgs e)
    {
        Form2 form2 = new Form2();
        form2.Show();
        Button1.Enabled = false;
    }

2nd Form name is : Form2

Consists from : nothing

但是有一个FormClosing事件

事件是:

        private void Form2_FormClosing(object sender, FormClosingEventArgs e)
    {
        Form1 form1 = new Form1();
        form1.Button1.Enabled = true;
    }

这意味着 Form1 中的 Button1 应该再次被Enabled。

The problem nothing happens when the Form2 is Closed

我认为那个事件是不正确的，但我不是很确定

感谢任何帮助

Answer 1

您需要将 Form1 的实例传递给 Form2，这样您就可以访问对象/表单...

public class Form2
{
  private Form1 _Form1;
  public Form2(Form1 form1)
  {
     this._Form1 = form1;
  }

  private void Form2_FormClosing(object sender, FormClosingEventArgs e)
  {
      _Form1.Button1.Enabled = true;
  }    
}

...

public class Form1
{
  private void Button1_Click(object sender, EventArgs e)
  {
    Form2 form2 = new Form2(this); //pass "this", ie the instance of Form1
    form2.Show();
    Button1.Enabled = false;
   }
 }