I'm trying to create a PDF Object from binary XString in xCode. (OData from SAP, utf-8)

Here is the coding:

const char* buf = [temp1 UTF8String];
pdffile = [NSData dataWithBytes:buf length:length1];
[webDisplay loadData:self.pdffile MIMEType:@"application/pdf" textEncodingName:@"utf-8" baseURL:nil];
self.webDisplay.scalesPageToFit = YES;

temp1 is a XString length1 is the length of PDF file in bytes.

I get following error message:

failed to find PDF header: '%PDF' not found

Some ideas? Thanks!