"Reprint" MFC dynamically creates a control and its message response function

Original: http://blog.sina.com.cn/s/blog_4a08244901014ok1.html

These days, we've been specifically investigating how to dynamically create a control and its message response function in MFC.

Refer to the following posts:

(1) http://topic.csdn.net/u/20101204/13/5f1b1e70-2f1c-4205-ba10-41616d16f07e.html

(2) http://www.cppblog.com/deercoder/articles/107132.html

These two posts are more classic and can answer my questions. But how do you dynamically create a message response function? This requires the use of a different command:

On_command_range

Refer to the following posts: http://topic.csdn.net/t/20020728/22/906766.html

Note: On_command_range maps a set of control IDs with their corresponding message response functions, because the message response function of which control ID is to be differentiated is required by the parameter:UINT NID

Here I built a new MFC project, and began to test the use of the above posts. After repeated comparisons, it is found that there is one more detail to note:

You need to include the control ID of the initialization in the string table, as follows:

Open the String table in the resource, double-click on a blank line, and an ID property dialog pops up, enter the ID in the ID edit box, such as: Idc_mybutton, enter the control title or annotation in caption (Note: the caption box cannot be empty, Null will cause the creation to fail), here I enter the button to display the text-the dynamic button.
This way, there is no error in the subsequent operation.

The specific code is as follows:

(1) build the control ID number: add a new Id:idc_mybutton to the string table. Note Keep distance from the value of the default ID

(2) Create a Control object:
Note You cannot define CButton objects directly, such as: CButton m_mybut; This definition can only be used to define control variables for static controls and not for dynamic controls.

For a dialog resource, first associate a class, such as Ctestdlg

Then join in the CTestDlg.cpp position:

On_command_range (IDC_MYBUTTON,IDC_MYBUTTON+10,&CTESTDLG::ONMYBTN)

As shown below:

Begin_message_map (Ctestdlg, CDialog)
On_command_range (IDC_MYBUTTON,IDC_MYBUTTON+10,&CTESTDLG::ONMYBTN)
On_bn_clicked (Idc_button1, &ctestdlg::onbnclickedbutton1)
On_bn_clicked (Idc_button2, &ctestdlg::onbnclickedbutton2)
End_message_map ()
Then add a function to create the control:

cbutton* Ctexteditorview::newmybutton (int nid,crect rect,int nstyle) { CString m_caption; M_caption.loadstring (NID); Take button title CButton *p_button = new CButton (); Assert_valid (P_button); P_button->create (m_caption, Ws_child | ws_visible | Bs_pushbutton | Nstyle, rect, this, NID); Create button return P_button; }

Then a new button (Idc_button1) is created using the Toolbox so that the button's message response function is used to create three new buttons. Its message response functions are as follows:

void Ctestdlg::onbnclickedbutton1 ()
{
TODO: Add control notification Handler code here
if (Btn_flag==false)

{

P_mybut[0] = Newmybutton (Idc_mybutton, CRect (20,20,50,60), Bs_defpushbutton);
P_MYBUT[1] = Newmybutton (idc_mybutton+1, CRect (70,20,95,50), 0);
P_MYBUT[2] = Newmybutton (idc_mybutton+50, CRect (120,20,140,35), 0);
btn_flag=p_mybut[0] && p_mybut[1] && p_mybut[2]; Btn_flag=true;
}

}

Also set a button (Idc_button2), press this button to destroy the previously created three new buttons.

void Ctestdlg::onbnclickedbutton2 ()
{
if (btn_flag)
{
if (p_mybut[0]) Delete p_mybut[0];
if (p_mybut[1]) Delete p_mybut[1];
if (p_mybut[2]) Delete p_mybut[2];
Btn_flag=false;
}
}

Set global variable: bool Btn_flag; used to indicate whether Button1 was pressed and three new buttons were created

Set global variables: CButton *p_mybut[3]; to store the new three buttons

The message response function for these three buttons is as follows: Note that you need to add parameters!

void Ctestdlg::onmybtn (UINT nID)
{
int index = Nid-idc_mybutton;

CString strbtn;
Strbtn.format (_t ("button%d"), index);
MessageBox (STRBTN);
}

========================================================

The last function is to press Button1 to generate three new buttons, each of which can trigger a messagebox. Press Button2 to destroy the three newly generated buttons.

"Reprint" MFC dynamically creates a control and its message response function