Custom Draw Custom draw is not a common control; it is a service that many common controls provide. Custom draw services allow an application greater flexibility in customizing a control's appearance. Your application can harness custom draw notifications to easily change the font used to display items or manually draw an item without having to do a full-blown owner draw. About Custom Draw Using Custom Draw Custom Draw Reference About Custom Draw This section contains general information about custom draw functionality and provides a conceptual overview of how an application can support custom draw. Currently, the following controls support custom draw functionality: Header controls List view controls Rebar controls Toolbar controls Tooltip controls Trackbar controls Tree view controls Note Custom draw is implemented in version 4.70 and later of Comctl32.dll. About Custom Draw Notification Messages All common controls that support custom draw send NM_CUSTOMDRAW notification messages at specific points during drawing operations. These notifications describe drawing operations that apply to the entire control as well as drawing operations specific to items within the control. Like many notification messages, NM_CUSTOMDRAW notifications are sent as WM_NOTIFY messages. The lParam parameter of a custom draw notification message will be the address of an NMCUSTOMDRAW structure or a control-specific structure that contains an NMCUSTOMDRAW structure as its first member. The following table illustrates the relationship between the controls and the structures they use. Structure Used by NMCUSTOMDRAW Rebar, trackbar, and header controls NMLVCUSTOMDRAW List view controls NMTBCUSTOMDRAW Toolbar controls NMTTCUSTOMDRAW Tooltip controls NMTVCUSTOMDRAW Tree view controls Paint Cycles, Drawing Stages, and Notification Messages Like all Microsoft® Windows® applications, common controls periodically paint and erase themselves based on messages received from the system or other applications. The process of a control painting or erasing itself is called a paint cycle. Controls that support custom draw send NM_CUSTOMDRAW notification messages periodically through each paint cycle. This notification message is accompanied by an NMCUSTOMDRAW structure or another structure that contains an NMCUSTOMDRAW structure as its first member. One piece of information that the NMCUSTOMDRAW structure contains is the current stage of the paint cycle. This is referred to as the draw stage and is represented by the value in the structure's dwDrawStage member. A control informs its parent about four basic draw stages. These basic, or global, draw stages are represented in the structure by the following flag values (defined in Commctrl.h). Global draw stage values CDDS_PREPAINT Before the paint cycle begins. CDDS_POSTPAINT After the paint cycle is complete. CDDS_PREERASE Before the erase cycle begins. CDDS_POSTERASE After the erase cycle is complete. Each of the preceding values can be combined with the CDDS_ITEM flag to specify draw stages specific to items. For convenience, Commctrl.h contains the following item-specific values. Item-specific draw stage values CDDS_ITEMPREPAINT Before an item is drawn. CDDS_ITEMPOSTPAINT After an item has been drawn. CDDS_ITEMPREERASE Before an item is erased. CDDS_ITEMPOSTERASE After an item has been erased. Your application must process the NM_CUSTOMDRAW notification message and then return a specific value that informs the control what it must do. See the following sections for more information about these return values. Taking Advantage of Custom Draw Services The key to harnessing custom draw functionality is in responding to the NM_CUSTOMDRAW notification messages that a control sends. The return values your application sends in response to these notifications determine the control's behavior for that paint cycle. This section contains information about how your application can use NM_CUSTOMDRAW notification return values to determine the control's behavior. Details are broken into the following topics: Responding to the prepaint notification Requesting item-specific notifications Drawing the item yourself Changing fonts and colors Responding to the prepaint notification At the beginning of each paint cycle, the control sends the NM_CUSTOMDRAW notification message, specifying the CDDS_PREPAINT value in the dwDrawStage member of the accompanying NMCUSTOMDRAW structure. The value that your application returns to this first notification dictates how and when the control sends subsequent custom draw notifications for the rest of that paint cycle. Your application can return a combination of the following flags in response to the first notification. Return value Effect CDRF_DODEFAULT The control will draw itself. It will not send additional NM_CUSTOMDRAW notifications for this paint cycle. This flag cannot be used with any other flag. CDRF_NOTIFYITEMDRAW The control will notify the parent of any item-specific drawing operations. It will send NM_CUSTOMDRAW notification messages before and after it draws items. CDRF_NOTIFYPOSTPAINT The control will send an NM_CUSTOMDRAW notification when the painting cycle for the entire control is complete. CDRF_SKIPDEFAULT The control will not perform any painting at all. Requesting item-specific notifications If your application returns CDRF_NOTIFYITEMDRAW to the initial prepaint custom draw notification, the control will send notifications for each item it draws during that paint cycle. These item-specific notifications will have the CDDS_ITEMPREPAINT value in the dwDrawStage member of the accompanying NMCUSTOMDRAW structure. You can request that the control send another notification when it is finished drawing the item by returning CDRF_NOTIFYPOSTPAINT to these item-specific notifications. Otherwise, return CDRF_DODEFAULT and the control will not notify the parent window until it starts to draw the next item. Drawing the item yourself If your application draws the entire item, return CDRF_SKIPDEFAULT. This allows the control to skip items that it does not need to draw, thereby decreasing system overhead. Keep in mind that returning this value means the control will not draw any portion of the item. Changing fonts and colors Your application can use custom draw to change an item's font. Simply select the HFONT you want into the device context specified by the hdc member of the NMCUSTOMDRAW structure associated with the custom draw notification. Since the font you select might have different metrics than the default font, make sure you include the CDRF_NEWFONT bit in the return value for the notification message. For more information on using this functionality, see the sample code in Using Custom Draw. The font that your application specifies is used to display that item when it is not selected. Custom draw does not allow you to change the font attributes for selected items. To change text colors for all controls that support custom draw except for the list view and tree view, simply set the desired text and background colors in the device context supplied in the custom draw notification structure with theSetTextColor andSetBkColor functions. To modify the text colors in the list view or tree view, you need to place the desired color values in the clrText and clrTextBk members of the NMLVCUSTOMDRAW or NMTVCUSTOMDRAW structure.
2.Custom Draw：处理CustomDraw通知消息，用GDI函数绘制界面
如果你想问的是在一行的不同列可以有图标
那直接设置ListItem.ListSubItems(Idx).ReportIcon属性
Custom draw is not a common control; it is a service that many common controls provide. Custom draw services allow an application greater flexibility in customizing a control's appearance. Your application can harness custom draw notifications to easily change the font used to display items or manually draw an item without having to do a full-blown owner draw. About Custom Draw
Using Custom Draw
Custom Draw Reference
About Custom Draw
This section contains general information about custom draw functionality and provides a conceptual overview of how an application can support custom draw. Currently, the following controls support custom draw functionality: Header controls
List view controls
Rebar controls
Toolbar controls
Tooltip controls
Trackbar controls
Tree view controls
Note Custom draw is implemented in version 4.70 and later of Comctl32.dll. About Custom Draw Notification Messages
All common controls that support custom draw send NM_CUSTOMDRAW notification messages at specific points during drawing operations. These notifications describe drawing operations that apply to the entire control as well as drawing operations specific to items within the control. Like many notification messages, NM_CUSTOMDRAW notifications are sent as WM_NOTIFY messages. The lParam parameter of a custom draw notification message will be the address of an NMCUSTOMDRAW structure or a control-specific structure that contains an NMCUSTOMDRAW structure as its first member. The following table illustrates the relationship between the controls and the structures they use. Structure Used by
NMCUSTOMDRAW Rebar, trackbar, and header controls
NMLVCUSTOMDRAW List view controls
NMTBCUSTOMDRAW Toolbar controls
NMTTCUSTOMDRAW Tooltip controls
NMTVCUSTOMDRAW Tree view controls
Paint Cycles, Drawing Stages, and Notification Messages
Like all Microsoft® Windows® applications, common controls periodically paint and erase themselves based on messages received from the system or other applications. The process of a control painting or erasing itself is called a paint cycle. Controls that support custom draw send NM_CUSTOMDRAW notification messages periodically through each paint cycle. This notification message is accompanied by an NMCUSTOMDRAW structure or another structure that contains an NMCUSTOMDRAW structure as its first member. One piece of information that the NMCUSTOMDRAW structure contains is the current stage of the paint cycle. This is referred to as the draw stage and is represented by the value in the structure's dwDrawStage member. A control informs its parent about four basic draw stages. These basic, or global, draw stages are represented in the structure by the following flag values (defined in Commctrl.h). Global draw stage values
CDDS_PREPAINT Before the paint cycle begins.
CDDS_POSTPAINT After the paint cycle is complete.
CDDS_PREERASE Before the erase cycle begins.
CDDS_POSTERASE After the erase cycle is complete.
Each of the preceding values can be combined with the CDDS_ITEM flag to specify draw stages specific to items. For convenience, Commctrl.h contains the following item-specific values. Item-specific draw stage values
CDDS_ITEMPREPAINT Before an item is drawn.
CDDS_ITEMPOSTPAINT After an item has been drawn.
CDDS_ITEMPREERASE Before an item is erased.
CDDS_ITEMPOSTERASE After an item has been erased.
Your application must process the NM_CUSTOMDRAW notification message and then return a specific value that informs the control what it must do. See the following sections for more information about these return values. Taking Advantage of Custom Draw Services
The key to harnessing custom draw functionality is in responding to the NM_CUSTOMDRAW notification messages that a control sends. The return values your application sends in response to these notifications determine the control's behavior for that paint cycle. This section contains information about how your application can use NM_CUSTOMDRAW notification return values to determine the control's behavior. Details are broken into the following topics: Responding to the prepaint notification
Requesting item-specific notifications
Drawing the item yourself
Changing fonts and colors
Responding to the prepaint notification
At the beginning of each paint cycle, the control sends the NM_CUSTOMDRAW notification message, specifying the CDDS_PREPAINT value in the dwDrawStage member of the accompanying NMCUSTOMDRAW structure. The value that your application returns to this first notification dictates how and when the control sends subsequent custom draw notifications for the rest of that paint cycle. Your application can return a combination of the following flags in response to the first notification. Return value Effect
CDRF_DODEFAULT The control will draw itself. It will not send additional NM_CUSTOMDRAW notifications for this paint cycle. This flag cannot be used with any other flag.
CDRF_NOTIFYITEMDRAW The control will notify the parent of any item-specific drawing operations. It will send NM_CUSTOMDRAW notification messages before and after it draws items.
CDRF_NOTIFYPOSTPAINT The control will send an NM_CUSTOMDRAW notification when the painting cycle for the entire control is complete.
CDRF_SKIPDEFAULT The control will not perform any painting at all.
Requesting item-specific notifications
If your application returns CDRF_NOTIFYITEMDRAW to the initial prepaint custom draw notification, the control will send notifications for each item it draws during that paint cycle. These item-specific notifications will have the CDDS_ITEMPREPAINT value in the dwDrawStage member of the accompanying NMCUSTOMDRAW structure. You can request that the control send another notification when it is finished drawing the item by returning CDRF_NOTIFYPOSTPAINT to these item-specific notifications. Otherwise, return CDRF_DODEFAULT and the control will not notify the parent window until it starts to draw the next item. Drawing the item yourself
If your application draws the entire item, return CDRF_SKIPDEFAULT. This allows the control to skip items that it does not need to draw, thereby decreasing system overhead. Keep in mind that returning this value means the control will not draw any portion of the item. Changing fonts and colors
Your application can use custom draw to change an item's font. Simply select the HFONT you want into the device context specified by the hdc member of the NMCUSTOMDRAW structure associated with the custom draw notification. Since the font you select might have different metrics than the default font, make sure you include the CDRF_NEWFONT bit in the return value for the notification message. For more information on using this functionality, see the sample code in Using Custom Draw. The font that your application specifies is used to display that item when it is not selected. Custom draw does not allow you to change the font attributes for selected items. To change text colors for all controls that support custom draw except for the list view and tree view, simply set the desired text and background colors in the device context supplied in the custom draw notification structure with theSetTextColor andSetBkColor functions. To modify the text colors in the list view or tree view, you need to place the desired color values in the clrText and clrTextBk members of the NMLVCUSTOMDRAW or NMTVCUSTOMDRAW structure.
Infragistics NetAdvantage 2003 Vol 3 COM 完全版