public static bool isValidPPTFile(byte[] bytFile, String FileContentType)
{
bool isvalid = false;
UsingFileExtension imgfileExtn = UsingFileExtension.none;
byte[] chkBytePPT = { 208, 207, 17, 224, 161, 177, 26, 225 };
if (FileContentType.Contains("application/vnd.ms-powerpoint"))
{
imgfileExtn = UsingFileExtension.PPT;
}
if (imgfileExtn == UsingFileExtension.PPT)
{
if (bytFile.Length >= 4)
{
int j = 0;
for (Int32 i = 0; i <= 3; i++)
{
if (bytFile[i] == chkBytePPT[i])
{
j = j + 1;
if (j == 3)
{
isvalid = true;
}
}
}
}
}
return(isvalid);
}
public static bool isValidPPTXFile(byte[] bytFile, String FileContentType)
{
bool isvalid = false;
UsingFileExtension imgfileExtn = UsingFileExtension.none;
byte[] chkBytePPTX = { 80, 75, 3, 4 };
if (FileContentType.Contains("application/vnd.openxmlformats-officedocument.presentationml.presentation"))
{
imgfileExtn = UsingFileExtension.PPTX;
}
if (imgfileExtn == UsingFileExtension.PPTX)
{
if (bytFile.Length >= 4)
{
int j = 0;
for (Int32 i = 0; i <= 3; i++)
{
if (bytFile[i] == chkBytePPTX[i])
{
j = j + 1;
if (j == 3)
{
isvalid = true;
}
}
}
}
}
return(isvalid);
}
public static bool isValidPDFFile(byte[] bytFile, String FileContentType)
{
bool isvalid = false;
UsingFileExtension imgfileExtn = UsingFileExtension.none;
byte[] chkBytePDF = { 37, 80, 68, 70, 45, 49, 46 };
if (FileContentType.Contains("application/pdf"))
{
imgfileExtn = UsingFileExtension.PDF;
}
if (imgfileExtn == UsingFileExtension.PDF)
{
if (bytFile.Length >= 4)
{
int j = 0;
for (Int32 i = 0; i <= 3; i++)
{
if (bytFile[i] == chkBytePDF[i])
{
j = j + 1;
if (j == 3)
{
isvalid = true;
}
}
}
}
}
return(isvalid);
}
