FRead3 Function |  |
Read characters from a file into an allocated buffer.
Namespace: XSharp.RT
Assembly: XSharp.RT (in XSharp.RT.dll) Version: 2.21
SyntaxFUNCTION FRead3( ptrHandle AS IntPtr, ptrBufferVar AS IntPtr, dwBytes AS DWORD ) AS DWORD
public static uint FRead3( IntPtr ptrHandle, IntPtr ptrBufferVar, uint dwBytes )
Parameters
- ptrHandle
- Type: IntPtr
The handle of the file to read from. - ptrBufferVar
- Type: IntPtr
Pointer to an allocated buffer used to store data read from the specified file.
The length of this variable must be greater than or equal to dwBytes. - dwBytes
- Type: DWord
The number of bytes to read into the buffer.
Return Value
Type: DWordThe number of bytes successfully read.
A return value less than dwBytes or 0 indicates end-of-file or some other read error. FError() can be used to determine the specific error.
Remarks
FRead3() is the same as FRead(), except that the name of the buffer variable is a pointer and is not passed by reference.
See FRead() for details.
This function is assumed to handle raw binary data and is not dependent upon the status of SetAnsi(). FReadText() and FRead4(), on the other hand, are dependent upon SetAnsi().
Remarks Tip |
|---|
| This function is included for compatibility. We do not recomment using static memory for file i/o operations. We recommend that you use the function overload that takes a byte array parameter in stead. |
Examples
This example uses FRead3() after successfully opening a file to read 128 bytes into a buffer area:
X#
1DEFINE F_BLOCK := 128 2Function Start() 3 LOCAL cBuffer AS PTR 4 cBuffer := MemAlloc(F_BLOCK) 5 IF cBuffer = NULL PTR 6 RETURN FALSE 7 ENDIF 8 ptrHandle := FOpen2("temp.txt", FO_READ) 9 IF ptrHandle = F_ERROR 10 ? DOSErrString(FError()) 11 RETURN FALSE 12 ELSE 13 IF FRead3(ptrHandle, cBuffer, F_BLOCK) <paramref name="" /> F_BLOCK 14 ? DOSErrString(FError()) 15 RETURN FALSE 16 ENDIF 17 FClose(ptrHandle) 18 ENDIF 19 MemFree(cBuffer) 20 RETURN TRUE
See Also