Crear un archivo csv desde una matriz de datos en iOS

Question

Quiero escribir datos del archivo sql en un archivo csv. He recopilado todos los datos del archivo sql en una matriz y usando for loop, agrego y escribo datos en el archivo .csv. pero parece que muestra datos en una línea, pero no va a la nueva línea para crear una nueva fila. He usado this como referencia. Este es mi código:

-(NSString *)dataFilePath { 
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
    NSString *documentsDirectory = [paths objectAtIndex:0]; 
    return [documentsDirectory stringByAppendingPathComponent:@"myfile.csv"]; 
} 

- (IBAction)saveAsFileAction:(id)sender {  
    if (![[NSFileManager defaultManager] fileExistsAtPath:[self dataFilePath]]) { 
     [[NSFileManager defaultManager] createFileAtPath: [self dataFilePath] contents:nil attributes:nil]; 
     NSLog(@"Route creato");   
    } 

    NSString *writeString;  
    for (int i=0; i<[dataArray count]; i++) {   
     writeString = [NSString stringWithFormat:@"%@, %@, %@, %@, %0.2f,",[[dataArray objectAtIndex:i]dates],[[dataArray objectAtIndex:i] time],[[dataArray objectAtIndex:i] category],[[dataArray objectAtIndex:i]place],[[dataArray objectAtIndex:i] amount]];   
     NSLog(@"writeString :%@",writeString);   
     NSFileHandle *handle; 
     handle = [NSFileHandle fileHandleForWritingAtPath: [self dataFilePath] ]; 
     //say to handle where's the file fo write 
     [handle truncateFileAtOffset:[handle seekToEndOfFile]]; 
     //position handle cursor to the end of file 
     [handle writeData:[writeString dataUsingEncoding:NSUTF8StringEncoding]];  
    }  
} 

Answer 1

Esto sólo se escribe una línea debido a reescribir el archivo cada vez que vaya a través de su bucle. Lo mejor es no writeData en el archivo hasta que el ciclo se haya completado. También me gustaría utilizar un NSMutableString así:

- (IBAction)saveAsFileAction:(id)sender { 

    if (![[NSFileManager defaultManager] fileExistsAtPath:[self dataFilePath]]) { 
     [[NSFileManager defaultManager] createFileAtPath: [self dataFilePath] contents:nil attributes:nil]; 
     NSLog(@"Route creato"); 
    } 

    NSMutableString *writeString = [NSMutableString stringWithCapacity:0]; //don't worry about the capacity, it will expand as necessary 

    for (int i=0; i<[dataArray count]; i++) { 
     writeString = [writeString appendString:[NSString stringWithFormat:@"%@, %@, %@, %@, %0.2f, \n",[[dataArray objectAtIndex:i]dates],[[dataArray objectAtIndex:i] time],[[dataArray objectAtIndex:i] category],[[dataArray objectAtIndex:i]place],[[dataArray objectAtIndex:i] amount]]]; //the \n will put a newline in 
     } 
    } 

    //Moved this stuff out of the loop so that you write the complete string once and only once. 
    NSLog(@"writeString :%@",writeString); 

    NSFileHandle *handle; 
    handle = [NSFileHandle fileHandleForWritingAtPath: [self dataFilePath] ]; 
    //say to handle where's the file fo write 
    [handle truncateFileAtOffset:[handle seekToEndOfFile]]; 
    //position handle cursor to the end of file 
    [handle writeData:[writeString dataUsingEncoding:NSUTF8StringEncoding]]; 
}  

Answer 2

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES); 
    NSString *documentsDir = [paths objectAtIndex:0]; 
    NSString *root = [documentsDir stringByAppendingPathComponent:@"customers.csv"]; 

    NSString *temp; 

    temp = [NSString stringWithFormat:@"%@", [arrCustomersName objectAtIndex:0]]; 

    for (int i = 1; i < [arrCustomersName count]; i++) { 

     temp = [temp stringByAppendingFormat:@", %@", [arrCustomersName objectAtIndex:i]]; 
    } 

    [temp writeToFile:root atomically:YES encoding:NSUTF8StringEncoding error:NULL]; 

Answer 3

En lugar de:

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES); 
NSString *documentsDir = [paths objectAtIndex:0]; 
NSString *root = [documentsDir stringByAppendingPathComponent:@"customers.csv"]; 

... acaba de escribir:

NSString *root = [NSHomeDirectory() stringByAppendingPathComponent:@"customers.csv"]; 

Exactamente mismo resultado para una sola línea corta de código. ; O)

Answer 4

// For CSV File : 
     NSMutableString *stringToWrite = [[NSMutableString alloc] init]; 
[stringToWrite appendString:[NSString stringWithFormat:@"First Name,Last Name,Full Name,Phone Number, Email,Job, organizationName,Note\n\n"]]; 
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ 
     for(int i = 0 ;i<[Contact count];i++)  { 
      [stringToWrite appendString:[NSString stringWithFormat:@"%@,",[[Contact objectAtIndex:i] valueForKey:@"firstName"] ]]; 
      [stringToWrite appendString:[NSString stringWithFormat:@"%@,",[[Contact objectAtIndex:i] valueForKey:@"lastName"] ]]; 
      [stringToWrite appendString:[NSString stringWithFormat:@"%@,",[[Contact valueForKey:@"userName"] objectAtIndex:i]]]; 
      [stringToWrite appendString:[NSString stringWithFormat:@"%@,",[[Contact objectAtIndex:i] valueForKey:@"phoneNumber"] ]]; 
      [stringToWrite appendString:[NSString stringWithFormat:@"%@,",[[Contact objectAtIndex:i] valueForKey:@"emailAddress"] ]]; 
      [stringToWrite appendString:[NSString stringWithFormat:@"%@,",[[Contact objectAtIndex:i] valueForKey:@"jobTitle"] ]]; 
      [stringToWrite appendString:[NSString stringWithFormat:@"%@,",[[Contact objectAtIndex:i] valueForKey:@"organizationName"] ]]; 
      [stringToWrite appendString:[NSString stringWithFormat:@"%@\n",[[Contact objectAtIndex:i] valueForKey:@"note"] ]]; 
     } 
     dispatch_async(dispatch_get_main_queue(), ^(void) { 
      NSArray *paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES); 
      NSString *documentDirectory=[paths objectAtIndex:0]; 
      NSString *strBackupFileLocation = [NSString stringWithFormat:@"%@/%@", documentDirectory,@"ContactList.csv"]; 
      [stringToWrite writeToFile:strBackupFileLocation atomically:YES encoding:NSUTF8StringEncoding error:nil]; 
     }); 
}); 

Answer 5

Prueba esto que está funcionando para mí,

Si alguien quiere crear .csv en rápida 3

// MARK: CSV file creating 
    func creatCSV() -> Void { 

    let fileName = "Tasks.csv" 

    let path = NSURL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(fileName) 
    var csvText = "Date,Task Name,Time Started,Time Ended\n" 

    for task in taskArr { 
     let newLine = "\(task.date),\(task.name),\(task.startTime),\(task.endTime)\n" 
     csvText.append(newLine) 
    } 

    do { 
     try csvText.write(to: path!, atomically: true, encoding: String.Encoding.utf8) 
    } catch { 
     print("Failed to create file") 
     print("\(error)") 
    } 
    print(path ?? "not found") 
    } 
    } 

Para más detalles se puede hacer referencia Detail Answer

Espero que esto ayude a alguien.