CListCtrl For Beginners(转蝲)

Tauruser — Wed, 07 Mar 2007 13:23:00 GMT

The List Control (MFC CListCtrl class) is the type of control that the Windows Explorer uses for it's right-side pane, but figuring out how to use the control can be a different kind of pain. The control is usually used only in "report view", which provides columns for each item. The following shows the basics of adding data to a List Control:

int Index;
// Insert columns
ListCtrl.InsertColumn( 0 , " One " , LVCFMT_LEFT, - 1 , 0 );
ListCtrl.InsertColumn( 1 , " Two " , LVCFMT_LEFT, - 1 , 1 );
// Insert first row
Index = ListCtrl.InsertItem(LVIF_TEXT, 0 , " One one " , 0 , 0 , 0 , NULL);
ListCtrl.SetItem(Index, 1 , LVIF_TEXT, " One two " , 0 , 0 , 0 , NULL);
// Insert second row
Index = ListCtrl.InsertItem(LVIF_TEXT, 1 , " Two one " , 0 , 0 , 0 , NULL);
ListCtrl.SetItem(Index, 1 , LVIF_TEXT, " Two two " , 0 , 0 , 0 , NULL);
// Set column widths (an optional nice touch)
ListCtrl.SetColumnWidth( 0 , LVSCW_AUTOSIZE);
ListCtrl.SetColumnWidth( 1 , LVSCW_AUTOSIZE);

If you are using CListView, then you will need to use something such as the following to access the CListCtrl:

CListCtrl &ListCtrl = GetListCtrl();

Note that for these to work, the control must have the "LVS_REPORT" style. For list controls in dialogs, including dialogs for CFormView, this style can be set in the dialog editor. If you are using CListView or you are creating list controls using Create, the style can be set in a PreCreateWindow override, as in:

BOOL CDumpView::PreCreateWindow(CREATESTRUCT& cs) {
cs.style |= LVS_REPORT;
return CListView::PreCreateWindow(cs);
}

Getting a Count of Columns

The solution for determining the number of columns is not obvious. You must get the header control from the list control and get the number of items (rows) in the header control. So I suggest putting the following in your header:

CHeaderCtrl *GetHeaderCtrl() const {return (CHeaderCtrl*)GetDlgItem(0);};
int GetColumnsCount() const {return GetHeaderCtrl()->GetItemCount();};

Deleting All Columns

Using GetColumnsCount() from above, it is easy to delete all columns.

void CListControl::DeleteAllColumns() {
int i, n;
n = GetColumnsCount();
for (i=0; i<n; ++i)
DeleteColumn(0);
}

Confusing Terminology

Microsoft has made things very confusing because the Platform SDK name for a listbox is "ListBox Control" but MFC programmers usually use "list control" to refer to an instance of the CListCtrl class, which is confusing. Also, the MFC class name for a "List View Control" is CListCtrl and CListView is the view class for it. The MFC class name for a "ListBox Control" is CListBox so we would expect the view class for it to also be CListView except there is not a view class. The following summarizes this.

Platform SDK name:List Boxes
Window class name: ListBox (See under "Predefined Controls" in User Controls and the documentation for CreateWindow and CreateWindowEx)
MFC class name:CListBox
MFC view class name: none

Platform SDK name:ListView Control
Window class name: SysListView32 (use WC_LISTVIEW in source code instead, which is defined as "SysListView32")
MFC class name:CListCtrl
MFC view class name:CListView

Tauruser 2007-03-07 21:23 发表评论

MFC ComboBox 使用�Ҏ��Q��{载）

Tauruser — Wed, 28 Feb 2007 02:29:00 GMT

MFC ComboBox 使用�Ҏ��Q��{载）

Combo box controls are space savers. Wherever there is no need for a multi-select from a list of items, combo box is a good choice in such places. This article " CComboBox Example" explains how to use the MFC CComboBox class for manipulation of a list of strings.

CComboBox Example - Initializing a Combo Box:

It is assumed that the readers of the sample have already created a dialog box (either in a dialog based application or SDI/MDI application) and placed a combo box control from the controls toolbox on the Resource Editor.

After placing the combo box control on the dialog box, open the class wizard by pressing Ctrl + W keys or Menu --> View --> ClassWizard. In the Member Variables tab, Add a Variable for the CComboBox class. This CComboBox example assumes that the variable name is,

CComboBox m_cbExample;

This m_cbExample will be used further in our CComboBox example MFC code.

CComboBox Example - Adding Items to a Combo Box:

The function AddString is used for adding items to a combo box. If there is a constant set of data, these values can also be added in the Resource Editor itself. The Combo Box control properties dialog has a tab for adding data. Otherwise the data can be added as follows.

    m_cbExample.AddString("StringData1");
    m_cbExample.AddString("StringData2");
    m_cbExample.AddString("StringData3");

CComboBox Example - Retrieving Items from a Combo Box:

Usually
a requirement for retrieving items from the combo box will arise from selecting the data. This article also assumes the same. Now the data selected in a combo box needs to be retrieved.

To do this, the first step is to find out the index of the selected item inside the combo box control.
Then the item at the corresponding position needs to be pulled out as follows.

    int nIndex = m_cbExample.GetCurSel();
    CString strCBText;

    m_cbExample.GetLBText(
nIndex, strCBText);

In the above CComboBox example code, the value will be retrieved and stored in strCBText variable. There is another overloaded version for GetLBText. But the version which uses CString is the easiest one.

CComboBox Example - Finding Items inside a Combo Box:

This kind of Find operations on a Combo box will most probably be useful in programs that dynamically modify the values in a combo box. The function FindStringExact is used to find the exact string match inside a combo box.

int nIndex = m_cbExample.FindStringExact(0, "Value to be found");

The string position inside the combo box control is the return value. It returns CB_ERR if it was unsuccessful in finding the string.

CComboBox Example - Deleting Items from a Combo Box:

This operation can be done by using the CCombobox member function DeleteString. This function needs the index of the item inside the combo box.

m_cbExample
.DeleteString(nIndex);

Tauruser 2007-02-28 10:29 发表评论

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CListCtrl For Beginners(转蝲)

Confusing Terminology

MFC ComboBox 使用�Ҏ���Q��{载）

MFC ComboBox 使用�Ҏ���Q��{载）

CComboBox Example - Initializing a Combo Box:

CComboBox Example - Adding Items to a Combo Box:

CComboBox Example - Retrieving Items from a Combo Box:

CComboBox Example - Finding Items inside a Combo Box:

CComboBox Example - Deleting Items from a Combo Box:

MFC ComboBox 使用�Ҏ��Q��{载）

MFC ComboBox 使用�Ҏ��Q��{载）