检测表单关闭的原因

Question

如何检测窗口窗体是如何关闭的？例如，如何确定用户是否单击了关闭表单的按钮，或者用户是否单击了右上角的“X”？谢谢。

更新：

忘了说按钮调用了 Application.Exit() 方法。

Answer 1

正如 bashmohandes 和 Dmitriy Matveev 已经提到的，解决方案应该是 FormClosingEventArgs。但正如 Dmitriy 所说，这不会对您的按钮和右上角的 X 产生任何影响。

要区分这两个选项，您可以在表单中添加一个布尔属性 ExitButtonClicked，并在调用 Application.Exit() 之前在按钮 Click-Event 中将其设置为 true。 p>

现在您可以在 FormClosing 事件中询问此属性，并在案例 UserClosing 中区分这两个选项。

例子：

    public bool UserClosing { get; set; }

    public FormMain()
    {
        InitializeComponent();

        UserClosing = false;
        this.buttonExit.Click += new EventHandler(buttonExit_Click);
        this.FormClosing += new FormClosingEventHandler(Form1_FormClosing);
    }

    void buttonExit_Click(object sender, EventArgs e)
    {
        UserClosing = true;
        this.Close();
    }

    void Form1_FormClosing(object sender, FormClosingEventArgs e)
    {
        switch (e.CloseReason)
        {
            case CloseReason.ApplicationExitCall:
                break;
            case CloseReason.FormOwnerClosing:
                break;
            case CloseReason.MdiFormClosing:
                break;
            case CloseReason.None:
                break;
            case CloseReason.TaskManagerClosing:
                break;
            case CloseReason.UserClosing:
                if (UserClosing)
                {
                    //what should happen if the user hitted the button?
                }
                else
                {
                    //what should happen if the user hitted the x in the upper right corner?
                }
                break;
            case CloseReason.WindowsShutDown:
                break;
            default:
                break;
        }

        // Set it back to false, just for the case e.Cancel was set to true
        // and the closing was aborted.
        UserClosing = false;
    }

Answer 2

您可以在 FormClosing 事件处理程序中检查 FormClosingEventArgs 的 CloseReason 属性以检查一些可能的情况。但是，如果您只使用此属性，您描述的情况将无法区分。您需要在“关闭”按钮的单击事件处理程序中编写一些额外的代码来存储一些信息，这些信息将在 FormClosing 事件处理程序中检查以区分这些情况。

Answer 3

您需要向 Even FormClosing 添加一个侦听器，它会在事件 args 中发送一个 CloseReason 类型的属性，该属性是这些值之一

    // Summary:
//     Specifies the reason that a form was closed.
public enum CloseReason
{
    // Summary:
    //     The cause of the closure was not defined or could not be determined.
    None = 0,
    //
    // Summary:
    //     The operating system is closing all applications before shutting down.
    WindowsShutDown = 1,
    //
    // Summary:
    //     The parent form of this multiple document interface (MDI) form is closing.
    MdiFormClosing = 2,
    //
    // Summary:
    //     The user is closing the form through the user interface (UI), for example
    //     by clicking the Close button on the form window, selecting Close from the
    //     window's control menu, or pressing ALT+F4.
    UserClosing = 3,
    //
    // Summary:
    //     The Microsoft Windows Task Manager is closing the application.
    TaskManagerClosing = 4,
    //
    // Summary:
    //     The owner form is closing.
    FormOwnerClosing = 5,
    //
    // Summary:
    //     The System.Windows.Forms.Application.Exit() method of the System.Windows.Forms.Application
    //     class was invoked.
    ApplicationExitCall = 6,
}