How to create controls at runtime?

Question

How to create dynamic MFC controls and handle message maps of the controls at runtime?

Accepted Answer

It really depends on which controls do you want to create, especially if you want to know which flags should you set. In general it goes down to this:

Normally a CWnd-derived control is created using `Create` or `CreateEx`. For a CButton, for instance:

```
CButton button;
button.Create("Button text", WS_CHILD | WS_VISIBLE | WS_TABSTOP | BS_PUSHBUTTON | DT_CENTER, CRect(5, 5, 55, 19), this, nID);
```

where the `CRect` specifies the button position, `this` is a pointer to the parent window, and `nID` is the control ID.

If the control doesn't come out as expected, it's probably because some flags are missing. I suggest you draw a sample control in design mode, check out the code for that control in the RC file, and copy the flags to the `Create` caller.

As for the message maps, they are normally routed to the parent window. The `nID` value you used in `Create` is important here, because it will be the number that identifies the control in the message map. If you have a fixed number of controls, you can hard-code the `nID` numbers for your controls (starting at 10000, for instance); if not, you'll have to provide a way for the parent window to identify them. Then you just add the message map entries.

```
ON_BN_CLICKED(10000, OnBnClicked)
ON_CONTROL_RANGE(BN_CLICKED, 10010, 10020, OnBtnsClicked)
```

You can use the `ON_CONTROL_RANGE` message map to map a range of IDs to the same function.

How to create controls at runtime?

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