iphone pdf下载

我无法检查文件是否存在，然后单击再次下载，或实际显示请求已完成的pdf文件。对此有何解决方案？

要检查文件是否存在，请使用：

        -(IBAction)click;
    {

            NSURL *url = [NSURL URLWithString:URL_TO_DOWNLOAD]; 
            NSString *tempDownloadPath = [[self documentsDirectory] 
                                          stringByAppendingPathComponent:@"test.pdf"]; 
            ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; 
            [request setDownloadDestinationPath:[self documentsDirectory]]; 
            [request setTemporaryFileDownloadPath:tempDownloadPath]; 
            [request setDelegate:self]; 

  [request startAsynchronous]; 


        } 

    - (void)requestFinished:(ASIHTTPRequest *)request 
        { 
            NSLog(@"requestFinished"); 
            NSError *error; 
            NSFileManager *fileManager = [[NSFileManager alloc] init]; 
            NSLog(@"Documents directory: %@", [fileManager 
                                               contentsOfDirectoryAtPath:[self 
                                                                          documentsDirectory] error:&error]); 
            NSString *dir = [self documentsDirectory]; 
            NSLog(dir); 
            // NSData *responseData = [request responseData]; 
            NSArray *array = [[NSFileManager defaultManager] 
                              contentsOfDirectoryAtPath:dir error:&error]; 
            if (array == nil) { 
                NSLog(@"array == nil"); 
            } 
else
{
[aWebView loadRequest:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:tempDownloadPath]]];
        [[self view] addSubview:aWebView];  
}

            [fileManager release]; 
                } 

    - (NSString *)documentsDirectory { 
            NSArray *paths = 
            NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, 
                                                NSUserDomainMask, 
                                                YES); 
            return [paths objectAtIndex:0]; 
        } 

要在请求完成后显示PDF，可以在

UIWebView

中打开它，或者使用

CGPDF*

函数集渲染它

ASIHTTPRequest的

setDownloadDestinationPath

希望收到一个绝对文件路径，而您似乎只是传递documents目录。 您可以从URL获取文件名并将其附加到文档目录路径：

BOOL exists = [[NSFileManager defaultManager] fileExistsAtPath:file]

然后，要检查下载的文件是否确实存在，可以再次使用

destPath

NSString *filename = [[url absoluteString] lastPathComponent];

NSString *directory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES) objectAtIndex:0];
NSString *destPath = [directory stringByAppendingPathComponent:filename];

[request setDownloadDestinationPath:destPath];