NSURLDownload Not Being Detected in SDK 4.2

Ey guys, here is my code:

#import <Foundation/Foundation.h>开发者_C百科
@interface Updater : NSObject {

    NSURLConnection *updateConnection;
    NSURLDownload *downloadConnection; //error at this line

}

@end

This is the error I am getting at the marked line:

Updater.h:15: error: expected specifier-qualifier-list before 'NSURLDownload'

Any idea why I am getting this error message? I have included the Foundation Framework and am stumped as to why the compiler is complaining, especially considering it doesn't complain at all about NSURLConnection. Thanks!

NSURLDownload class is available on MacOS only, on iOS you should use NSURLConnection. From docs:

iOS Note: The NSURLDownload class is not available in iOS, because downloading directly to the file system is discouraged. Use the NSURLConnection class instead

If you have large chunk of data to download and want to avoid memory issues you can use NSFileHandle class in connection delegate to write received data directly to disk instead of keeping it in memory.

As you read in iOS Note: it's not possible to use NSURLDownload on ios yet, but the link provided below shows you a simple way to download whatever you want from the net to the application sand box. Hope you like it. Cheers http://www.ifans.com/forums/showthread.php?t=169611

------------ Below is the link ------------

//
//  UIDownloadBar.h
//  UIDownloadBar
//
//  Created by John on 3/20/09.
//  Copyright 2009 Gojohnnyboi. All rights reserved.
//

#import <UIKit/UIKit.h>

@class UIProgressView;
@protocol UIDownloadBarDelegate;

@interface UIDownloadBar : UIProgressView {
    NSURLRequest* DownloadRequest;
    NSURLConnection* DownloadConnection;
    NSMutableData* receivedData;
    NSString* localFilename;
    id<UIDownloadBarDelegate> delegate;
    long long bytesReceived;
    long long expectedBytes;

    float percentComplete;
}

- (UIDownloadBar *)initWithURL:(NSURL *)fileURL progressBarFrame:(CGRect)frame timeout:(NSInteger)timeout delegate:(id<UIDownloadBarDelegate>)theDelegate;

@property (nonatomic, readonly) NSMutableData* receivedData;
@property (nonatomic, readonly, retain) NSURLRequest* DownloadRequest;
@property (nonatomic, readonly, retain) NSURLConnection* DownloadConnection;
@property (nonatomic, assign) id<UIDownloadBarDelegate> delegate;

@property (nonatomic, readonly) float percentComplete;

@end

@protocol UIDownloadBarDelegate<NSObject>

@optional
- (void)downloadBar:(UIDownloadBar *)downloadBar didFinishWithData:(NSData *)fileData suggestedFilename:(NSString *)filename;
- (void)downloadBar:(UIDownloadBar *)downloadBar didFailWithError:(NSError *)error;
- (void)downloadBarUpdated:(UIDownloadBar *)downloadBar;

@end


//
//  UIDownloadBar.m
//  UIDownloadBar
//
//  Created by John on 3/20/09.
//  Copyright 2009 Gojohnnyboi. All rights reserved.
//

#import "UIDownloadBar.h"


@implementation UIDownloadBar

@synthesize DownloadRequest, 
    DownloadConnection,
    receivedData,
    delegate,
    percentComplete;


- (UIDownloadBar *)initWithURL:(NSURL *)fileURL progressBarFrame:(CGRect)frame timeout:(NSInteger)timeout delegate:(id<UIDownloadBarDelegate>)theDelegate {
    self = [super initWithFrame:frame];
    if(self) {
        self.delegate = theDelegate;
        bytesReceived = percentComplete = 0;
        localFilename = [[[fileURL absoluteString] lastPathComponent] copy];
        receivedData = [[NSMutableData alloc] initWithLength:0];
        self.progress = 0.0;
        self.backgroundColor = [UIColor clearColor];
        DownloadRequest = [[NSURLRequest alloc] initWithURL:fileURL cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:timeout];
        DownloadConnection = [[NSURLConnection alloc] initWithRequest:DownloadRequest delegate:self startImmediately:YES];

        if(DownloadConnection == nil) {
            [self.delegate downloadBar:self didFailWithError:[NSError errorWithDomain:@"UIDownloadBar Error" code:1 userInfo:[NSDictionary dictionaryWithObjectsAndKeys:@"NSURLConnection Failed", NSLocalizedDescriptionKey, nil]]];
        }
    }

    return self;
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [self.receivedData appendData:data];

    NSInteger receivedLen = [data length];
    bytesReceived = (bytesReceived + receivedLen);

    if(expectedBytes != NSURLResponseUnknownLength) {
        self.progress = ((bytesReceived/(float)expectedBytes)*100)/100;
        percentComplete = self.progress*100;
    }

    [delegate downloadBarUpdated:self];
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    [self.delegate downloadBar:self didFailWithError:error];
    [connection release];
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    expectedBytes = [response expectedContentLength];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    [self.delegate downloadBar:self didFinishWithData:self.receivedData suggestedFilename:localFilename];
    [connection release];
}

- (void)drawRect:(CGRect)rect {
    [super drawRect:rect];
}

- (void)dealloc {
    [localFilename release];
    [receivedData release];
    [DownloadRequest release];
    [DownloadConnection release];
    [super dealloc];
}


@end