C ++ / CLI - 如何打开一个新的表单和回来 [英] C++/CLI - how to open a new form and back

问题描述

我创建一个应用程序，前端必须是使用C ++ / CLI的Windows窗体。该表单用于登录目的。

在我的表单中，我有一个注册按钮。点击这个按钮，一个新的窗体应该打开（关闭登录窗体）。我可以通过以下代码实现这一点：

  Form ^ rgForm = gcnew RegisterForm; 
 rgForm-> Show（）; 
 this-> Hide（）; // using this-> Close（）关闭应用程序
  

现在我想要取消按钮，其单击应再次打开登录表单并关闭注册表单。我如何实现呢？

（我对使用this-> Hide（）感到困惑，是否意味着表单存在，我们只是没有显示它，因此即使在注册表单可见性之后，登录表单仍然存在？）

更新：现在当前窗体句柄被传递到注册表单构造函数变量在RegisterForm类中的名称为loginForm）。

以下是取消按钮点击的代码：

  // RegisterForm类构造函数
 
 RegisterForm（System :: Windows :: Forms :: Form ^ f）
 {
 loginForm = f; 
} 
 
 //取消按钮点击
 
 private：System :: Void BtnCancel_Click（System :: Object ^ sender，System :: EventArgs ^ e）
 {
 loginForm-> Show（）; 
 this-> Hide（）; 
} 
  

取消按钮单击我得到异常：对象未设置为实例

有人可以帮助我。

谢谢。

RegisterForm 创建一个构造函数，它接受一个 System :: Windows :: Form ^ 对象，并且当您在登录表单类中实例化时，将 传递给它

  Form ^ rgForm = gcnew RegisterForm（this）; 
 rgForm-> Show（）; 
 this-> Hide（）; 
  

假设登录表单对象被调用 otherform 在RegisterForm类中。一旦准备好恢复，只需调用 otherform-> Show（）

编辑：我得到这个工作很好。以下是我对表单

所做的修改（而不是完整代码）：

Form2（注册表）

  Form2（System :: Windows :: Forms :: Form ^ frm1）
 {
 otherform = frm1; 
 InitializeComponent（）; 
 
} 
 
 private：System :: Windows :: Forms :: Form ^ otherform; 
 
 private：System :: Void Cancel_Click（System :: Object ^ sender，System :: EventArgs ^ e）{
 this-> Hide 
 otherform-> Show（）; 
   

}

Form1登录表单）

  #includeForm2.h
 
 private： ：Void Register_Click（System :: Object ^ sender，System :: EventArgs ^ e）{
 
 Form2 ^ frm2 = gcnew Form2（this）; 
 frm2-> Show（）; 
 this-> Hide（）; 
} 
  

I am creating an application where the front end has to be a Windows Form using C++/CLI. The form is used for login purpose.

In my form, I have a register button. On click of this button, a new form should open ( closing the login form ). I was able to achieve this by the following code:

Form^ rgForm = gcnew RegisterForm;
rgForm->Show();
this->Hide(); // using this->Close() was closing the application

Now I want to have a cancel button on the register form, whose click should open the login form again and close the register form. How do I achieve that?

( I am confused with the use of this->Hide(), does it mean that the form exists, we just did not show it, and so even after the register form visibility, the login form still exists? )

Update : Now current form handle is passed into register form constructor ( storing it as a private variable with the name loginForm in RegisterForm class ).

Following is the code for cancel button click:

// RegisterForm class constructor

RegisterForm(System::Windows::Forms::Form^ f)
{
    loginForm = f;
}

// Cancel button click

private: System::Void BtnCancel_Click(System::Object^  sender, System::EventArgs^  e) 
{
     loginForm->Show();
     this->Hide();
}

On cancel button click I am getting the exception : "object not set to instance".

Can someone please help me.

Thanks.

解决方案

Create a constructor for RegisterForm which accepts a System::Windows::Form ^ object, and pass this to it when you are instantiating it from within the login form class

Form^ rgForm = gcnew RegisterForm(this);
rgForm->Show();
this->Hide();

Assume the login form object is called otherform within the RegisterForm class. Once you're ready to bring it back, just call otherform->Show()

When you hide the form, it still exists, it is just not visible to the user.

EDIT: I got this to work just fine. Here are the modifications (not the full code) that I made to the form

Form2(Registration form)

Form2(System::Windows::Forms::Form ^ frm1)
    {
        otherform = frm1;
        InitializeComponent();

    }

private: System::Windows::Forms::Form ^ otherform;

private: System::Void Cancel_Click(System::Object^  sender, System::EventArgs^  e) {
             this->Hide();
             otherform->Show();

}

Form1(Login form)

#include "Form2.h"

private: System::Void Register_Click(System::Object^  sender, System::EventArgs^  e) {

             Form2 ^ frm2 = gcnew Form2(this);
             frm2->Show();
             this->Hide();
}

这篇关于C ++ / CLI - 如何打开一个新的表单和回来的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！