GrayString
The GrayString
function draws gray text at the specified location. The function draws the text
by copying it into a memory bitmap, graying the bitmap, and then copying the
bitmap to the screen. The function grays the text regardless of the selected
brush and background. GrayString uses the font currently selected for
the specified device context.
If the lpOutputFunc
parameter is NULL, GDI uses the TextOut function, and the lpData parameter is
assumed to be a pointer to the character string to be output. If the characters
to be output cannot be handled by TextOut (for example, the string is
stored as a bitmap), the application must supply its own output function.
BOOL GrayString(
|
HDC hDC, |
// handle to the
device context |
|
HBRUSH hBrush, |
// handle to the
brush for graying |
|
GRAYSTRINGPROC lpOutputFunc, |
// pointer to the
callback function |
|
LPARAM lpData, |
// pointer to
application-defined data |
|
int nCount, |
// number of
characters to output |
|
int X, |
// horizontal
position |
|
int Y, |
// vertical
position |
|
int nWidth, |
// width |
|
int nHeight |
// height |
|
); |
|
Parameters
hDC
Identifies
the device context.
hBrush
Identifies
the brush to be used for graying. If this parameter is NULL, the text is grayed
with the same brush that was used to draw window text.
lpOutputFunc
Points to the
application-defined function that will draw the string, or, if TextOut
is to be used to draw the string, it is a NULL pointer. For details, see the OutputProc callback function.
lpData
Specifies a
pointer to data to be passed to the output function. If the lpOutputFunc
parameter is NULL, lpData must be a pointer to the string to be output.
nCount
Specifies the
number of characters to be output. If the nCount parameter is zero, GrayString
calculates the length of the string (assuming lpData is a pointer to the
string). If nCount is -1
and the function pointed to by lpOutputFunc returns FALSE, the image is
shown but not grayed.
X
Specifies the
device x-coordinate of the starting position of the rectangle that encloses the
string.
Y
Specifies the
device y-coordinate of the starting position of the rectangle that encloses the
string.
nWidth
Specifies the
width, in device units, of the rectangle that encloses the string. If this
parameter is zero, GrayString calculates the width of the area, assuming
lpData is a pointer to the string.
nHeight
Specifies the
height, in device units, of the rectangle that encloses the string. If this
parameter is zero, GrayString calculates the height of the area,
assuming lpData is a pointer to the string.
Return Values
If the string
is drawn, the return value is nonzero.
If either the
TextOut function or the application-defined output function returned
zero, or there was insufficient memory to create a memory bitmap for graying,
the return value is zero.
Remarks
Without
calling GrayString, an application can draw grayed strings on devices
that support a solid gray color. The system color COLOR_GRAYTEXT is the
solid-gray system color used to draw disabled text. The application can call
the GetSysColor function to retrieve the color value of COLOR_GRAYTEXT.
If the color is other than zero (black), the application can call the SetTextColor
function to set the text color to the color value and then draw the string
directly. If the retrieved color is black, the application must call GrayString
to gray the text.
See Also