CMFCHeaderCtrl Class
The latest version of this topic can be found at CMFCHeaderCtrl Class.
The CMFCHeaderCtrl class supports sorting multiple columns in a header control.
Syntax
class CMFCHeaderCtrl : public CHeaderCtrl
Members
Public Constructors
| Name | Description |
|---|---|
| CMFCHeaderCtrl::CMFCHeaderCtrl | Constructs a CMFCHeaderCtrl object. |
CMFCHeaderCtrl::~CMFCHeaderCtrl |
Destructor. |
Public Methods
| Name | Description |
|---|---|
| CMFCHeaderCtrl::EnableMultipleSort | Enables or disables multiple column sort mode for the current header control. |
| CMFCHeaderCtrl::GetColumnState | Indicates whether a column is not sorted, or is sorted in ascending or descending order. |
| CMFCHeaderCtrl::GetSortColumn | Retrieves the zero-based index of the first sorted column in the header control. |
CMFCHeaderCtrl::GetThisClass |
Used by the framework to obtain a pointer to the CRuntimeClass object that is associated with this class type. |
| CMFCHeaderCtrl::IsAscending | Indicates whether any column in the header control is sorted in ascending order. |
| CMFCHeaderCtrl::IsDialogControl | Indicates whether the parent window of the current header control is a dialog box. |
| CMFCHeaderCtrl::IsMultipleSort | Indicates whether the current header control is in multiple column sort mode. |
| CMFCHeaderCtrl::RemoveSortColumn | Removes the specified column from the list of sort columns. |
| CMFCHeaderCtrl::SetSortColumn | Sets the sort order of a specified column in a header control. |
Protected Methods
| Name | Description |
|---|---|
| CMFCHeaderCtrl::OnDrawItem | Called by the framework to draw a header control column. |
| CMFCHeaderCtrl::OnDrawSortArrow | Called by the framework to draw the sort arrow. |
| CMFCHeaderCtrl::OnFillBackground | Called by the framework to fill the background of a header control column. |
Example
The following example demonstrates how to construct an object of the CMFCHeaderCtrl class, and how to enable multiple column sort mode for the current header control.
CMFCHeaderCtrl* headerCtrl = new CMFCHeaderCtrl();
headerCtrl->EnableMultipleSort();
Remarks
The CMFCHeaderCtrl class draws a sort arrow on a header control column to indicate that the column is sorted. Use multiple column sort mode if a set of columns in the parent list control ( CMFCListCtrl Class) can be sorted at the same time.
Inheritance Hierarchy
Requirements
Header: afxheaderctrl.h
CMFCHeaderCtrl::CMFCHeaderCtrl
Constructs a CMFCHeaderCtrl object.
CMFCHeaderCtrl::CMFCHeaderCtrl
()
Remarks
This constructor initializes the following member variables to the specified values:
| Member variable | Value |
|---|---|
m_bIsMousePressed |
FALSE |
m_bMultipleSort |
FALSE |
m_bAscending |
TRUE |
m_nHighlightedItem |
-1 |
m_bTracked |
FALSE |
m_bIsDlgControl |
FALSE |
m_hFont |
NULL |
CMFCHeaderCtrl::EnableMultipleSort
Enables or disables multiple column sort mode for the current header control.
void EnableMultipleSort(BOOL bEnable=TRUE);
Parameters
[in] bEnable
TRUE to enable multiple column sort mode; FALSE to disable multiple column sort mode and to remove any columns from the list of sorted columns. The default value is TRUE.
Remarks
Use this method to enable or disable multiple column sort mode. Two or more columns can participate in a sort if the header control is in multiple column sort mode.
CMFCHeaderCtrl::GetColumnState
Indicates whether a column is unsorted, or is sorted in ascending or descending order.
int GetColumnState(int iColumn) const;
Parameters
[in] iColumn
The zero-based index of a column.
Return Value
A value that indicate the sort status of the specified column. The following table lists the possible values:
| Value | Description |
|---|---|
| -1 | Sorted in descending order. |
| 0 | Not sorted. |
| 1 | Sorted in ascending order. |
Remarks
CMFCHeaderCtrl::GetSortColumn
Retrieves the zero-based index of the first sorted column in the header control.
int GetSortColumn() const;
Return Value
The index of a sorted column, or -1 if no sorted column is found.
Remarks
If the header control is in multiple column sort mode and you compiled the application in debug mode, this method asserts and advises you to use the CMFCHeaderCtrl::GetColumnState method instead. If the header control is in multiple column sort mode and you compiled the application in retail mode, this method returns -1.
CMFCHeaderCtrl::IsAscending
Indicates whether any column in the header control is sorted in ascending order.
BOOL IsAscending() const;
Return Value
TRUE if any column in the header control is sorted in ascending order; otherwise, FALSE.
Remarks
The value that this method returns is used to display the appropriate sort arrow on the header control item. Use the CMFCHeaderCtrl::SetSortColumn method to set the sort order.
CMFCHeaderCtrl::IsDialogControl
Indicates whether the parent window of the current header control is a dialog box.
BOOL IsDialogControl() const;
Return Value
TRUE if the parent window of the current header control is a dialog box; otherwise, FALSE.
CMFCHeaderCtrl::IsMultipleSort
Indicates whether the current header control is in multiple column sort mode.
BOOL IsMultipleSort() const;
Return Value
TRUE if multiple column sort mode is enabled; otherwise, FALSE.
Remarks
Use the CMFCHeaderCtrl::EnableMultipleSort method to enable or disable multiple column sort mode. Two or more columns can participate in a sort if the header control is in multiple column sort mode.
CMFCHeaderCtrl::OnDrawItem
Called by the framework to draw a header control column.
virtual void OnDrawItem(
CDC* pDC,
int iItem,
CRect rect,
BOOL bIsPressed,
BOOL bIsHighlighted);
Parameters
[in] pDC
A pointer to a device context.
[in] iItem
The zero-based index of the item to draw.
[in] rect
The bounding rectangle of the item to draw.
[in] bIsPressed
TRUE to draw the item in pressed state; otherwise, FALSE.
[in] bIsHighlighted
TRUE to draw the item in highlighted state; otherwise, FALSE.
CMFCHeaderCtrl::OnDrawSortArrow
Called by the framework to draw the sort arrow.
virtual void OnDrawSortArrow(
CDC* pDC,
CRect rectArrow);
Parameters
[in] pDC
A pointer to a device context.
[in] rectArrow
The bounding rectangle of the sort arrow.
CMFCHeaderCtrl::OnFillBackground
Called by the framework to fill the background of a header control column.
virtual void OnFillBackground(CDC* pDC);
Parameters
[in] pDC
A pointer to a device context.
Remarks
CMFCHeaderCtrl::RemoveSortColumn
Removes the specified column from the list of sort columns.
void RemoveSortColumn(int iColumn);
Parameters
[in] iColumn
The zero-based index of the column to remove.
CMFCHeaderCtrl::SetSortColumn
Sets the sort order of a specified column in a header control.
void SetSortColumn(
int iColumn,
BOOL bAscending=TRUE,
BOOL bAdd=FALSE);
Parameters
[in] iColumn
The zero-based index of a header control column. If this parameter is less than zero, this method removes all columns from the list of sort columns.
[in] bAscending
Specifies the sort order of the column that the iColumn parameter specifies. TRUE to set ascending order; FALSE to set descending order. The default value is TRUE.
[in] bAdd
TRUE to set the sort order of the column that the iColumn parameter specifies.
If the current header control is in multiple column sort mode, this method adds the specified column to the list of sort columns. Use CMFCHeaderCtrl::EnableMultipleSort to set multiple column sort mode.
If multiple column sort mode is not set and this method is compiled in debug mode, this method asserts. If multiple column sort mode is not set and this method is compiled in retail mode, this method first removes all columns from the list of sort columns, and then adds the specified column to the list.
FALSE to first remove all columns from the list of sort columns, and then add the specified column to the list. The default value is FALSE.
Remarks
Use this method to set the sort order of a column. If necessary, this method adds the column to the list of sort columns. The header control uses the sort order to draw a sort arrow that points up or down.