C# FormClosing 和 FormClosed 事件不起作用

FormClosing and FormClosed events do not work

提问by Jean

I'm developing a C#app And i need do some validations before the user close the form.

我正在开发一个C#应用程序，我需要在用户关闭表单之前进行一些验证。

I tried to use the FormClosingevent, but it didn't work, later I used the FormClosedevent, but the same.

我尝试使用该FormClosing事件，但没有奏效，后来我使用了该FormClosed事件，但还是一样。

The problem is, when I click in the "close button" (on the top of the form) it doesn't do anything but i have the events in form properties and everything.

问题是，当我单击“关闭按钮”（在表单顶部）时，它什么也没做，但我在表单属性和所有内容中都有事件。

this is my code:

这是我的代码：

    private void Inicio_FormClosing_1(object sender, FormClosingEventArgs e)
    {
    //things I have to do
    //...
    //...

    if(bandera==true)
    Application.Exit();

    }

and

和

    private void Inicio_FormClosed_1(object sender, FormClosingEventArgs e)
    {
    //things I have to do
    //...
    //...

    if(bandera==true)
    Application.Exit();

    }

any idea?

任何的想法？

Thank you

谢谢

采纳答案by Jean

I found the mistake;

我发现了错误；

Here: (when I initialize my form)

这里：（当我初始化我的表单时）

    public Inicio()
    {
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.AutoScroll = true;

        this.ClientSize = new System.Drawing.Size(635, 332);
        this.StartPosition = FormStartPosition.CenterScreen;
        llenaForm(nombreFormulario);
        Application.EnableVisualStyles();

    }

All i needed was: InitializeComponent();
I deleted by mistake

我只需要： InitializeComponent();
我误删了

It should be:

它应该是：

    public Inicio()
    {
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.AutoScroll = true;`

        InitializeComponent();//<<<<<<<<------------------- 

        this.ClientSize = new System.Drawing.Size(635, 332);
        this.StartPosition = FormStartPosition.CenterScreen;
        llenaForm(nombreFormulario);
        Application.EnableVisualStyles();
    }

Thank you so much guys!

十分感谢大家！

回答by varocarbas

Both events should work fine. Just open a new project and do this simple test:

这两个事件都应该正常工作。只需打开一个新项目并进行这个简单的测试：

 private void Form1_Load(object sender, EventArgs e)
 {
     this.FormClosing += new FormClosingEventHandler(Inicio_FormClosing_1);
     this.FormClosed += new FormClosedEventHandler(Inicio_FormClosed_1);
 }

 private void Inicio_FormClosing_1(object sender, FormClosingEventArgs e)
 {
     //Things while closing

 }

 private void Inicio_FormClosed_1(object sender, FormClosedEventArgs e)
 {
     //Things when closed
 }

If you set break points in these methods, you would see that they are reached after the close button is clicked. It seems that there is some problem in your event-attaching code. For example: Inicio_FormClosed_1(object sender, FormClosingEventArgs e)is wrong, as far as it should take a FormClosedEventArgsargument; and thus this method is surely not associated with the FormClosed event(otherwise, the code wouldn't compile).

如果在这些方法中设置断点，您会看到在单击关闭按钮后到达它们。您的事件附加代码中似乎存在一些问题。例如：Inicio_FormClosed_1(object sender, FormClosingEventArgs e)是错误的，只要它需要一个FormClosedEventArgs论点；因此，此方法肯定与 无关FormClosed event（否则，代码将无法编译）。

回答by Brian Rogers

In order to prevent the user from closing a form in response to certain validations, you need to set FormClosingEventArgs.Cancel = true.

为了防止用户关闭表单以响应某些验证，您需要设置FormClosingEventArgs.Cancel = true.

For example:

例如：

private void Inicio_FormClosing_1(object sender, FormClosingEventArgs e)
{
    if (string.IsNullOrEmpty(txtSomethingRequired.Text))
    {
        MessageBox.Show("Something is required here!");
        if (txtSomethingRequired.CanFocus) txtSomethingRequired.Focus();
        e.Cancel = true;
        return;
    }
}

You can only do validations in the FormClosingevent to prevent the form from closing; if you wait until FormClosedit is already too late.

您只能在FormClosing事件中进行验证以防止表单关闭；如果你等到FormClosed已经太晚了。

回答by L_7337

I noticed you have an "_1" at the end of your method names. Did you rename these methods?

我注意到您的方法名称末尾有一个“_1”。你重命名了这些方法吗？

If so, your UI code(designer file) will need to be updated with these new method names.

如果是这样，您的 UI 代码（设计器文件）将需要使用这些新方法名称进行更新。

You can put a breakpoint in these methods to see if they are getting called.

您可以在这些方法中放置一个断点以查看它们是否被调用。

回答by Jamisco

Just as a side note, the Form.Hide() method does not raised the form_closed or form_closing events

作为旁注，Form.Hide() 方法不会引发 form_closed 或 form_closed 事件