Question

我正在尝试创建一个XML字符串并将其传递给另一个我使用HTTP POST将其发送到PHP脚本的方法。请参阅下面的日志文件，我可以创建XML字符串并将其显示在日志文件中，但我无法将其传递给postXMLFeed方法。

我做错了什么？

-(IBAction)syncUp { 
 [self createXMLFeed];
// [self postXMLFeed:XMLStr];
 [self postXMLFeed];
}


-(void)createXMLFeed{
 //Fetch details from the database.
 NSFetchRequest *request = [[NSFetchRequest alloc] init];
 NSEntityDescription *entity = [NSEntityDescription entityForName:@"Tabrss" inManagedObjectContext:managedObjectContext];
 [request setEntity:entity];
 NSError *error;
 self.stories = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy];
 [request release];

 // Count the number of items in the array and display in the log.
 int arrayItemQuantity = [stories count];
 NSLog(@"Array Quantity: %d", arrayItemQuantity);

 // Loop through the array and display the contents in the log.
 int i;
 for (i = 0; i < arrayItemQuantity; i++)
 {
  //NSString *XMLStr = [NSString stringWithFormat:@"<workout><id>%@</id><userid>%@</userid><walkid>%@</walkid><date>%@</date><distance>%@</distance><repeats>%@</repeats><type>%@</type><intensity>%@</intensity><comments>%@</comments><time>%@</time><weight>%@</weight><height>%@</height></workout>", 
  XMLStr = [NSString stringWithFormat:@"<workout><id>%@</id><userid>%@</userid><walkid>%@</walkid><date>%@</date><distance>%@</distance><repeats>%@</repeats><type>%@</type><intensity>%@</intensity><comments>%@</comments><time>%@</time><weight>%@</weight><height>%@</height></workout>", 
       [[stories objectAtIndex:i] valueForKey:@"ID"], 
       [[stories objectAtIndex:i] valueForKey:@"UserID"], 
       [[stories objectAtIndex:i] valueForKey:@"walkID"], 
       [[stories objectAtIndex:i] valueForKey:@"xDate"], 
       [[stories objectAtIndex:i] valueForKey:@"Distance"], 
       [[stories objectAtIndex:i] valueForKey:@"Repeats"], 
       [[stories objectAtIndex:i] valueForKey:@"Type"],
       [[stories objectAtIndex:i] valueForKey:@"Intensity"],
       [[stories objectAtIndex:i] valueForKey:@"Comments"],
       [[stories objectAtIndex:i] valueForKey:@"xTime"],
       [[stories objectAtIndex:i] valueForKey:@"Weight"],
       [[stories objectAtIndex:i] valueForKey:@"Height"]];

  NSLog (@"XML Feed1: %@", XMLStr); 
 }
 NSLog (@"XML Feed2: ", XMLStr);

 [stories release];  

 // Update log file.
 NSLog(@"Database read and XML feed created."); 
}


//-(void)postXMLFeed:(NSString *)XMLStr
-(void)postXMLFeed
{ 
 //XMLStr = @"<workout><id>1</id><userid>4</userid><walkid>20</walkid><date>2010-06-21 10:42:50</date><distance>12345</distance><repeats>1</repeats><type>StephenTesting</type><intensity>6.0</intensity><comments>testtesttest</comments><time>00:00:00</time><weight>65</weight><height>173</height></workout>";
 //XMLStr = @"<xml><id>Hello World!</id></xml>";
 NSLog (@"XML Feed3: ", XMLStr);

 NSURL *url = [NSURL URLWithString:@"http://192.168.1.200/stephen/sync_upload.php"];
 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
 [request setValue:@"text/xml" forHTTPHeaderField:@"Content-type"];
 [request setHTTPMethod:@"POST"];
 [request setHTTPBody:[XMLStr dataUsingEncoding:NSASCIIStringEncoding]];

 NSURLResponse *response;
 NSError *error;
 response = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];


 // Update log file.
 NSLog(@"XML feed POSTED to website: ", XMLStr);

 //[super postXMLFeed];
}

日志文件：

2010-06-25 14:34:38.001 TAB RSS[2229:207] XML Feed: <workout><id>27
  </id><userid>4
  </userid><walkid>
  </walkid><date>2010-06-21 10:42:25
  </date><distance>1000
  </distance><repeats>1
  </repeats><type>Walking
  </type><intensity>6.0
  </intensity><comments>asdf
  </comments><time>00:00:00
  </time><weight>65
  </weight><height>173
</height></workout>
2010-06-25 14:34:38.001 TAB RSS[2229:207] XML Feed: <workout><id>28
  </id><userid>4
  </userid><walkid>
  </walkid><date>2010-06-21 10:45:05
  </date><distance>152.4
  </distance><repeats>1
  </repeats><type>Hiking/Backpacking
  </type><intensity>8.0
  </intensity><comments>test
  </comments><time>00:00:00
  </time><weight>65
  </weight><height>173
</height></workout>
2010-06-25 14:34:38.002 TAB RSS[2229:207] XML Feed: <workout><id>29
  </id><userid>4
  </userid><walkid>
  </walkid><date>2010-06-21 12:31:28
  </date><distance>0
  </distance><repeats>1
  </repeats><type>Aikido
  </type><intensity>5.0
  </intensity><comments>Nice training
  </comments><time>01:30:00
  </time><weight>65
  </weight><height>173
</height></workout>
2010-06-25 14:34:38.002 TAB RSS[2229:207] XML Feed2: 
2010-06-25 14:34:38.003 TAB RSS[2229:207] Database read and XML feed created.
2010-06-25 14:34:38.004 TAB RSS[2229:207] XML Feed3: 
(gdb) continue
Current language:  auto; currently objective-c
2010-06-25 14:34:39.585 TAB RSS[2229:207] XML feed POSTED to website:

Answer 1

stringWithFormat:是一个NSString类方法。它不保留它返回的字符串，因此它只会在调用它的作用域的剩余部分中保留。如果您改为使用[[NSString alloc] initWithFormat:]，或者只是在XMLStr变量上调用retain，那么您应该可以在第二种方法中使用它。在第二种方法结束时完成它后，请记住release字符串。

Answer 2

您要将XMLStr分配给自动审核的NSString 我将假设XMLStr被声明为NSString属性，如下所示：

@interface XMLWriter : NSObject {
NSString *XMLStr;
}
@property (nonatomic, retain) NSString *XMLStr
@end

@implementation XMLWriter
@synthesize XMLStr;

在createXMLFeed更改：

XMLStr = [NSString ....

要：

self.XMLStr = [NSString ....

问题传递变量 - Objective-C

2 个答案: