Downloading files from uiwebview in iphone sdk

问题

Is there any way to download file from UIWebView i am using this code on my IBAction event

- (IBAction)saveFile:(id)sender {
// Get the URL of the loaded ressource
NSURL *theRessourcesURL = [[self.webDisplay request] URL];
NSString *fileExtension = [theRessourcesURL pathExtension];

if ([fileExtension isEqualToString:@"png"] || [fileExtension isEqualToString:@"jpg"] || 
    [fileExtension isEqualToString:@"pdf"] || [fileExtension isEqualToString:@"html"]) {
    // Get the filename of the loaded ressource form the UIWebView's request URL
    NSString *filename = [theRessourcesURL lastPathComponent];
    NSLog(@"Filename: %@", filename);
    // Get the path to the App's Documents directory
    NSString *docPath = [self documentsDirectoryPath];
    // Combine the filename and the path to the documents dir into the full path
    NSString *pathToDownloadTo = [NSString stringWithFormat:@"%@/%@", docPath, filename];


    // Load the file from the remote server
    NSData *tmp = [NSData dataWithContentsOfURL:theRessourcesURL];
    // Save the loaded data if loaded successfully
    if (tmp != nil) {
        NSError *error = nil;
        // Write the contents of our tmp object into a file
        [tmp writeToFile:pathToDownloadTo options:NSDataWritingAtomic error:&error];
        if (error != nil) {
            NSLog(@"Failed to save the file: %@", [error description]);
        } else {
            // Display an UIAlertView that shows the users we saved the file :)
            UIAlertView *filenameAlert = [[UIAlertView alloc] initWithTitle:@"File saved" message:[NSString stringWithFormat:@"The file %@ has been saved.", filename] delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
            [filenameAlert show];
            [filenameAlert release];
        }
    } else {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Warning" 
                                                        message:@"File could not be loaded" 
                                                       delegate:nil 
                                              cancelButtonTitle:@"Okay" 
                                              otherButtonTitles:nil];
        [alert show];
        [alert release];
        // File could notbe loaded -> handle errors
    }
} else {
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Warning" 
                                                    message:@"File type not supported" 
                                                   delegate:nil 
                                          cancelButtonTitle:@"Okay" 
                                          otherButtonTitles:nil];
    [alert show];
    [alert release];
    // File type not supported
}

} this code open the file in UIWebView , which i want to download and when i press the button the opened file get save. But i want my UIWebView to behave like normal browser , when the download link appear in it and user press it, UIWebView show dialog with option open it or save it if user press save the file get save automatically and if user press open it file should open in UIWebView.

回答1:

You can provide webView:shouldStartLoadWithRequest in your UIWebViewDelegate so that each time the user is about to move to another web page, you have the chance to check what the link looks like:

 - (BOOL)webView:(UIWebView*)webView shouldStartLoadWithRequest:(NSURLRequest*)request navigationType:(UIWebViewNavigationType)navigationType {

     if ([[[request URL] scheme] isEqual:@"http"] && 
         [[[request URL] pathExtension]...])
            <your download/save code here>
            return NO;  //-- no need to follow the link
     }
     return YES; //-- otherwise, follow the link
  }

来源：https://stackoverflow.com/questions/8076347/downloading-files-from-uiwebview-in-iphone-sdk