hi,klee:
Could you step into PDFOpen function in last of this help_IOS_1.7.pdf said.
In Create a method to open the PDF. Find [m_pdf PDFOpen:pdfFullpath], and make modified as follow
if([iosversion integerValue]>7)
{
m_view = [[PDFView alloc] initWithFrame:CGRectMake(0, 0, rect.size.width, rect.size.height)];
}
else
{
//modified here. do not use rect.size.height-20-hi.because in ios7 sdk navigationController.navigationBar.bounds.size.height's value is zero ,if you want use this correct in ios7 below,there should minus navigationBar's height
m_view = [[PDFView alloc] initWithFrame:CGRectMake(0, 0, rect.size.width, rect.size.height-20-44)];
}