CanvasDrawRect
int CanvasDrawRect (int panelHandle, int controlID, Rect rectangle, int drawMode);
Purpose
Draws a rectangle on the canvas control at the position and with the dimensions specified by the rect parameter.
CanvasDrawRect draws the frame of the rectangle using the current value of the following attributes:
ATTR_PEN_COLOR
ATTR_PEN_MODE
ATTR_PEN_WIDTH
ATTR_PEN_STYLE (ignored when pen width is greater than one)
CanvasDrawRect draws the interior of the rectangle using the current value of the following attributes:
ATTR_PEN_FILL_COLOR
ATTR_PEN_MODE
ATTR_PEN_PATTERN
Supported Controls
You can use CanvasDrawRect with canvas controls.
Parameters
| Input | ||
| Name | Type | Description |
| panelHandle | int | Specifier for a particular panel that is currently in memory. You can obtain this handle from functions such as LoadPanel and NewPanel. |
| controlID | int | The defined constant, located in the .uir header file, that you assigned to the control in the User Interface Editor, or the ID returned by functions such as NewCtrl and DuplicateCtrl. |
| rectangle | Rect | Rect structure specifying the location and size of the rectangle to be drawn. The Rect structure is defined as follows: typedef struct { int top; int left; int height; int width; } Rect; You can create a Rect without having to declare a variable by using the following function: Rect MakeRect (int top, int left, int height, int width); ExampleCanvasDrawRect (panelHandle, controlID, MakeRect(20,30,150,200), VAL_DRAW_FRAME); |
| drawMode | int | Specifies whether to draw the rectangle frame, or interior, or both. The following lists the valid values: VAL_DRAW_FRAME VAL_DRAW_INTERIOR VAL_DRAW_FRAME_AND_INTERIOR |
Return Value
| Name | Type | Description |
| status | int | Return value indicating whether the function was successful. A negative number indicates that an error occurred. |
Additional Information
Library: User Interface Library
Include file: userint.h
LabWindows/CVI compatibility: LabWindows/CVI 4.0 and later
Examples
Refer to the following examples that use the CanvasDrawRect function:
- apps\iconedit\iconedit.cws
Open example - apps\life\life.cws
Open example - userint\canvas.cws
Open example