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); }