Reading and Writing Blocks of Characters and Attributes

The ReadConsoleOutput function copies a rectangular block of character and color attribute data from a console screen buffer into a destination buffer. The function treats the destination buffer as a two-dimensional array of CHAR_INFO structures. Similarly, the WriteConsoleOutput function copies a rectangular block of character and color attribute data from a source buffer to a console screen buffer. For more information about reading from or writing to rectangular blocks of screen buffer cells, see Input and Output Methods.

The following example uses the CreateConsoleScreenBuffer function to create a new screen buffer. After the SetConsoleActiveScreenBuffer function makes this the active screen buffer, a block of characters and color attributes is copied from the top two rows of the SDTOUT screen buffer into a temporary buffer. The data is then copied from the temporary buffer into the new active screen buffer. When the application is finished using the new screen buffer, it calls SetConsoleActiveScreenBuffer to restore the original STDOUT screen buffer.

#include <windows.h>

VOID main(void) {

HANDLE hStdout, hNewScreenBuffer;

SMALL_RECT srctReadRect;

SMALL_RECT srctWriteRect;

CHAR_INFO chiBuffer[160]; // [2][80];

COORD coordBufSize;

COORD coordBufCoord;

BOOL fSuccess;

/*

* Get a handle of the STDOUT screen buffer to copy from and

* create a new screen buffer to copy to.

*/

hStdout = GetStdHandle(STD_OUTPUT_HANDLE);

hNewScreenBuffer = CreateConsoleScreenBuffer(

GENERIC_READ | /* read-write access */

GENERIC_WRITE,

0, /* not shared */

NULL, /* no security attributes */

CONSOLE_TEXTMODE_BUFFER, /* must be TEXTMODE */

NULL); /* reserved; must be NULL */

if (hStdout == INVALID_HANDLE_VALUE ||

hNewScreenBuffer == INVALID_HANDLE_VALUE)

MyErrorExit("CreateConsoleScreenBuffer");

/* Make the new screen buffer the active screen buffer. */

if (! SetConsoleActiveScreenBuffer(hNewScreenBuffer) )

MyErrorExit("SetConsoleActiveScreenBuffer");

/* Set the source rectangle. */

srctReadRect.Top = 0; /* top left: row 0, col 0 */

srctReadRect.Left = 0;

srctReadRect.Bottom = 1; /* bot. right: row 1, col 79 */

srctReadRect.Right = 79;

/* The temporary buffer size is 2 rows x 80 columns. */

coordBufSize.Y = 2;

coordBufSize.X = 80;

/*

* The top left destination cell of the temporary buffer is

* row 0, col 0.

*/

coordBufCoord.X = 0;

coordBufCoord.Y = 0;

/* Copy the block from the screen buffer to the temp. buffer. */

fSuccess = ReadConsoleOutput(

hStdout, /* screen buffer to read from */

chiBuffer, /* buffer to copy into */

coordBufSize, /* col-row size of chiBuffer */

coordBufCoord, /* top left dest. cell in chiBuffer */

&srctReadRect); /* screen buffer source rectangle */

if (! fSuccess)

MyErrorExit("ReadConsoleOutput");

/* Set the destination rectangle. */

srctWriteRect.Top = 10; /* top lt: row 10, col 0 */

srctWriteRect.Left = 0;

srctWriteRect.Bottom = 11; /* bot. rt: row 11, col 79 */

srctWriteRect.Right = 79;

/* Copy from the temporary buffer to the new screen buffer. */

fSuccess = WriteConsoleOutput(

hNewScreenBuffer, /* screen buffer to write to */

chiBuffer, /* buffer to copy from */

coordBufSize, /* col-row size of chiBuffer */

coordBufCoord, /* top left src cell in chiBuffer */

&srctWriteRect); /* dest. screen buffer rectangle */

if (! fSuccess)

MyErrorExit("WriteConsoleOutput");

Sleep(10000);

/* Restore the original active screen buffer. */

if (! SetConsoleActiveScreenBuffer(hStdout))

MyErrorExit("SetConsoleActiveScreenBuffer");

}