c#请求FormClosing

Question

我有一份表格要索取一些数据。在离开输入字段(TextBox，DGV)时，调用适当的_Validating方法或_CellValueChanged方法。

如果我想结束这个方法被调用的程序，那么在之前调用_FormClosing方法。

如何确定程序是否分支到_FormClosing方法中？

private void txb_Validating(object sender, CancelEventArgs e)
{
    doLog("Text 1");
}

private void dgv_CellValueChanged(object sender, DataGridViewCellEventArgs e)
{
    doLog("Text 2");
}

private void doLog(string txt)
{
    // this is first called at closing...
    if( [FormClosing is active] )
    {
        // Do something
    }
    else
    {
        // Do someting different
    }
}

private void MyForm_FormClosing(object sender, FormClosingEventArgs e)
{
    // ... and this but later
    // Write the Logfile
}

我如何替换FormClosing是主动的，以获得正确的结果？

我试过了

if ( this.FormClosing== true ) 

所以

this.FormClosing +=new FormClosingEventHandler(MyForm_FormClosing);

所以

FormClosingEventHandler cl = new FormClosingEventHandler(MyForm_FormClosing);

但我总是死路一条。

Answer 1

this.FormClosing是在表单开始关闭时触发的事件(如单击“关闭”按钮)，因此名称。您需要应用程序来注册该事件，如下所示：

 this.FormClosing +=new FormClosingEventHandler(MyForm_FormClosing);

这可以确保一旦触发了FormClosing事件，就会调用您的MyForm_FormClosing。

您可以创建一个类似于bool bIsFormClosing的标志，并在调用关闭函数后设置该标志。

编辑：

正如我现在通过查看您的答案和评论所理解的，您希望在您的doLog函数中知道表单是否正在关闭。

以下是另一种方法

`

public class YourForm : Form
{
    private bool bIsClosing = false;
    Private bool bClosingHandled = false;

    public YourClass()
    {
       InitializeComponent();
       this.FormClosing +=
           new FormClosingEventHandler(MyForm_FormClosing);
    }

    private void txb_Validating(object sender, CancelEventArgs e)
    {
        doLog("Text 1");
    }

    private void dgv_CellValueChanged(object sender,
        DataGridViewCellEventArgs e)
    {
        doLog("Text 2");
    }

    private void doLog(string txt)
    {
        // this is first called at closing...
        if( bIsClosing )
        {
            // Do something
            bClosingHandled = true;
            this.close(); 
        }
        else
        {
            // Do someting different
        }
    }

    private void MyForm_FormClosing(object sender, FormClosingEventArgs e)
    {
        If(!bClosingHandled)
        {
          bIsClosing = true;
          e.Cancel = true;
          return;
        }

        // Write the Logfile
        doLog("whatever");
    }
}`

这种方法使用两个标志..。当您第一次收到关闭事件时，您将bIsClosing标志设置为true，取消事件并返回。然后，一旦您的dolog函数被调用，您将强制关闭操作。

Answer 2

这就能起作用了：

public class YourForm : Form
{
    private bool bIsClosing = false;

    public YourClass()
    {
       InitializeComponent();
       this.FormClosing +=
           new FormClosingEventHandler(MyForm_FormClosing);
    }

    private void txb_Validating(object sender, CancelEventArgs e)
    {
        doLog("Text 1");
    }

    private void dgv_CellValueChanged(object sender,
        DataGridViewCellEventArgs e)
    {
        doLog("Text 2");
    }

    private void doLog(string txt)
    {
        // this is first called at closing...
        if( bIsClosing )
        {
            // Do something
        }
        else
        {
            // Do someting different
        }
    }

    private void MyForm_FormClosing(object sender, FormClosingEventArgs e)
    {
        bIsClosing = true;
        // Write the Logfile
        doLog("whatever");
    }
}