C＃关闭Winform选项卡式子窗体 [英] C# Closing Winform Tabbed Child Form

问题描述

您好，

我在关闭子表格时遇到了一些问题。

I'm having some problems making my Child Form being closed.

我有一个名为MdiParent的表单BackOffice有一个TreeView。当我点击一个节点时，它会打开一个新的表格"Contratos_List"。并为该表单创建一个Tab。到目前为止，非常好。

I've a MdiParent Form named BackOffice which has a TreeView. When I click on a node, it opens a new Form "Contratos_List" and creates a Tab for that form. So far, so Good.

当我尝试关闭Contratos_List时，按钮什么都不做。我一遍又一遍地搜索了很多论坛，但可以"弄清楚我的代码有什么问题。"

When I try to close the Contratos_List, the button does nothing. I searched over and over many forums, but can' figure what's wrong with my code.

所以，这就是我到目前为止所做的一切。

So, here's what I have so far.

这个是我的BackOffice表单代码：

This is my BackOffice Form code:

private void Backoffice_MdiChildActivate(object sender,
                                EventArgs e)
        {
            if (this.ActiveMdiChild == null)
                tabForms.Visible = false;
            // If no any child form, hide tabControl 
            else
            {
                this.ActiveMdiChild.WindowState =
                FormWindowState.Maximized;
                // Child form always maximized 

                // If child form is new and no has tabPage, 
                // create new tabPage 
                if (this.ActiveMdiChild.Tag == null)
                {
                    // Add a tabPage to tabControl with child 
                    // form caption 
                    int tpIndex = 0;
                    foreach (TabPage tpCheck in tabForms.TabPages)
                    {
                        if (tpCheck.Name == this.ActiveMdiChild.Name)
                        {
                            tabForms.SelectedIndex = tpIndex;
                            return;
                        }
                        tpIndex++;
                    }
                    TabPage tp = new TabPage(this.ActiveMdiChild.Text);
                    tp.Tag = this.ActiveMdiChild;
                    tp.Parent = tabForms;
                    tabForms.SelectedTab = tp;
                    this.ActiveMdiChild.Tag = tp;
                    this.ActiveMdiChild.FormClosed += new FormClosedEventHandler(ActiveMdiChild_FormClosed);
                }
                else
                {
                    TabPage tp = this.ActiveMdiChild.Tag as TabPage;
                    if (tp != null)
                        tabForms.SelectedTab = tp;
                }
                if (!tabForms.Visible) tabForms.Visible = true;
            }
        }

        private void tabForms_SelectedIndexChanged(object sender,
                                           EventArgs e)
        {
            if ((tabForms.SelectedTab != null) &&
                (tabForms.SelectedTab.Tag != null))
                (tabForms.SelectedTab.Tag as Form).Select();
        }

        private void ActiveMdiChild_FormClosed(object sender,
                                    FormClosedEventArgs e)
        {
            ((sender as Form).Tag as TabPage).Dispose();
        }

        private void padmintreeView_AfterSelect(object sender, TreeViewEventArgs e)
        {
            if (e.Node.Name == "contratos_node")
            {
                if (Application.OpenForms.OfType<Operacoes.Contratos.Contratos_List>().FirstOrDefault() != null)
                {
                    return;
                }
                Operacoes.Contratos.Contratos_List ct = new Operacoes.Contratos.Contratos_List { MdiParent = this, WindowState = FormWindowState.Maximized };
                ct.Show();
            }
        }

然后，我有Contratos_List表单关闭按钮：

Then, I have the Contratos_List Form close button:

private bool ChildWindowOpen(String childWindow)
        {
            foreach (Form f in this.MdiChildren)
            {
                if (f.Name == childWindow)
                    return true;
            }
            return false;
        }

        private void btn_fechar_Click(object sender, EventArgs e)
        {
            if (ChildWindowOpen("Contratos_List") == false)
            {
                if (this.ActiveMdiChild != null)
                    this.ActiveMdiChild.Close();
            }
        }

然后，无论我如何点击关闭按钮，子表单都不会关闭。

Then, no matters how I click on Close Button, the Child Form does not close.

她是BreakPoint的标题，显示ActiveMdiChild为空。

Her's a caption from a BreakPoint showing that ActiveMdiChild is null.

所以，如果有人能在这里帮助我，那会很棒，因为我不知道在哪里可以找到答案...

So, if anyone could help me here, it would be great because I don't know where to find some answers...

谢谢。

推荐答案

CarlosFerreira，

Hi CarlosFerreira,

> ;> 当我尝试关闭Contratos_List时，该按钮不执行任何操作

我认为您使用以下代码关闭名为" Contratos_List "：

I think you use the following code to close the form named "Contratos_List":

        private void btn_fechar_Click(object sender, EventArgs e)
        {
            if (ChildWindowOpen("Contratos_List") == false)
            {
                if (this.ActiveMdiChild != null)
                    this.ActiveMdiChild.Close();
            }
        }

请在此行设置一个断点：

Please set a break point in this line:

    if (this.ActiveMdiChild != null)

确定是否"this.ActiveMdiChild"是null，我担心它是null，所以你不能触发" this.ActiveMdiChild.Close（）"方法。

To determine if "this.ActiveMdiChild" is null, I'm afraid it is null so that you can not trigger "this.ActiveMdiChild.Close()" method.

实际上，如果要关闭名为" Contratos_List "的MDI子窗体，只需使用：

In fact, if you want to close the MDI child form named "Contratos_List", you just need to use:

    //this.ActiveMdiChild.Close();
    this.Close();

问候，

Frankie

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