如何从Objective-C中的服务器下载CSV文件 [英] How to download CSV file from server in Objective-C

问题描述

我正在开发一个新的iPhone应用程序，这里我解析了一个'csv'文件从本地，并与我的工作。当我尝试从服务器以编程方式下载'csv'文件，它没有为我锻炼。

pre> - （void）viewDidLoad
{
[super viewDidLoad];

NSString * file = [[NSBundle bundleForClass：[self class]] pathForResource：@sampleofType：@csv];

NSStringEncoding encoding = 0;
NSString * csv = [NSString stringWithContentsOfFile：file usedEncoding：& encoding error：nil];
NSArray * fields = [csv CSVComponents];
NSLog（@fields：％@，fields）; //获取结果内容
}


从服务器下载文件（失败）

   - （void）connectionDidFinishLoading：（NSURLConnection *）connection 
 {
 NSLog （@connectionDidFinishLoading）; //这里没有显示
 
 NSString * docDir = [NSSearchPathForDirectoriesInDomains（NSDocumentDirectory，NSUserDomainMask，YES）objectAtIndex：0]; 
 NSString * fullName = [NSString stringWithFormat：@quotes.csv]; 
 
 NSString * fullFilePath = [NSString stringWithFormat：@％@ /％@，docDir，fullName]; 
 [receivedData writeToFile：fullFilePath atomically：YES]; 
} 
 
  - （void）connection（NSURLConnection *）connection didReceiveData：（NSData *）data 
 {
 NSLog（@data：％@数据）; //这里没有显示
 
 if（receivedData）
 [receivedData appendData：data]; 
 else 
 receivedData = [[NSMutableData alloc] initWithData：data]; 
} 
 
  - （void）loadDatafromURL 
 {
 NSURL * url = [NSURL URLWithString：@http://download.finance.yahoo.com/d /quotes.csv?s=,GSPC,^IXIC,^dji,^GSPC,^BVSP,^GSPTSE,^FTSE,^GDAXI,^FCHI,^STOXX50E,^AEX,^IBEX,^SSMI,^N225,^ AXJO，^ HSI，^ NSEI& f = sl1d1t1c1ohgv& e = .csv]; 
 NSURLRequest * request = [NSURLRequest requestWithURL：url]; 
 [NSURLConnection connectionWithRequest：request delegate：self]; 
} 
  

解决方案

p>

   - （void）connection：（NSURLConnection *）conn didFailWithError：（NSError *）error 
  

您会发现您收到的错误

  Error Domain = NSURLErrorDomain Code = -1000bad URLUserInfo = 0xf663f40 {NSUnderlyingError = 0xf663de0bad URL，NSLocalizedDescription = bad URL} 
  

我以前一直在调查下载信息，我想你遇到的一个问题是，单独的符号必须用+分隔。此外，当拉取索引时，您不能将^符号作为URL的一部分。您必须用％5E替换。

因此，添加：

 code>  - （void）connection：（NSURLConnection *）connection didFailWithError：（NSError *）error {
 NSLog（@％@，[error description]）; 
} 
  

并将您的网址更改为：

  NSString * urlString = @http://download.finance.yahoo.com/d/quotes.csv?s=^GSPC+^IXIC+^dji+^GSPC+^ BVSP + ^ GSPTSE + ^ FTSE + ^ GDAXI + ^ FCHI + ^ STOXX50E + ^ AEX + ^ IBEX + ^ SSMI + ^ N225 + ^ AXJO + ^ HSI + ^ NSEI& f = sl1d1t1c1ohgv& e = .csv; 
 NSURL * url = [NSURL URLWithString：[urlString stringByAddingPercentEscapesUsingEncoding：NSASCIIStringEncoding]]; 
  

现在它适用于我！我甚至检查了输出.csv文件，它看起来不错！每行一个完整报价。

I'm developing a new iPhone application, Here i have parsed a 'csv' file from local, and its working with me. When i try to download the 'csv' file from the server programmatically, it didn't workout for me. Could you please help me?

Loading data from local file (Working fine)

- (void)viewDidLoad
{  
    [super viewDidLoad];

    NSString * file = [[NSBundle bundleForClass:[self class]] pathForResource:@"sample" ofType:@"csv"];

    NSStringEncoding encoding = 0;
    NSString * csv = [NSString stringWithContentsOfFile:file usedEncoding:&encoding error:nil];
    NSArray *fields = [csv CSVComponents];
    NSLog(@"fields: %@", fields); //getting the result content 
}

Download the file from Server (failed)

-(void) connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSLog(@"connectionDidFinishLoading"); //nothing showing here

    NSString *docDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString *fullName = [NSString stringWithFormat:@"quotes.csv"];

    NSString *fullFilePath = [NSString stringWithFormat:@"%@/%@",docDir,fullName];
    [receivedData writeToFile:fullFilePath atomically:YES];
} 

-(void) connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    NSLog(@"data: %@", data); //nothing showing here

    if (receivedData)
        [receivedData appendData:data];
    else 
        receivedData = [[NSMutableData alloc] initWithData:data];
}

- (void)loadDatafromURL
{    
    NSURL *url = [NSURL URLWithString:@"http://download.finance.yahoo.com/d/quotes.csv?s=^GSPC,^IXIC,^dji,^GSPC,^BVSP,^GSPTSE,^FTSE,^GDAXI,^FCHI,^STOXX50E,^AEX,^IBEX,^SSMI,^N225,^AXJO,^HSI,^NSEI&f=sl1d1t1c1ohgv&e=.csv"];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
    [NSURLConnection connectionWithRequest:request delegate:self];
}

解决方案

Implement this method:

-(void)connection:(NSURLConnection *)conn didFailWithError:(NSError *)error

You'll find that you're getting an error of

Error Domain=NSURLErrorDomain Code=-1000 "bad URL" UserInfo=0xf663f40 {NSUnderlyingError=0xf663de0 "bad URL", NSLocalizedDescription=bad URL}

I've looked into downloading information this way before, and I think one problem you're having is that separate symbols have to be separated with a "+". Also, when pulling an index, you can't pass the "^" symbol as part of the URL. You have to replace it with "%5E".

So, add this:

- (void) connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    NSLog(@"%@", [error description]);
}

And change your URL to this:

NSString *urlString = @"http://download.finance.yahoo.com/d/quotes.csv?s=^GSPC+^IXIC+^dji+^GSPC+^BVSP+^GSPTSE+^FTSE+^GDAXI+^FCHI+^STOXX50E+^AEX+^IBEX+^SSMI+^N225+^AXJO+^HSI+^NSEI&f=sl1d1t1c1ohgv&e=.csv";
NSURL *url = [NSURL URLWithString:[urlString stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding]];

Now it works for me! I even checked the output .csv file, and it looks good to go! One full quote per line.

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