浏览PDF的效果
方法一：利用webview
代码如下:
-(void)loadDocument:(NSString *)documentName inView:(UIWebView *)webView
{
NSString *path = [[NSBundle mainBundle] pathForResource:documentName ofType:nil];
NSURL *url = [NSURL fileURLWithPath:path];
NSURLRequest *request = [NSURLRequest requestWithU
