CODEWITHSUNDEEP
iphoneobjective-cnsstringbytensdata
Mark Worsnop
Mark Worsnop

Reputation: 4467

asyncSocket writeData crashes with different NSData

If I use this to set up NSData then the writeData method crashes. 

   NSString *test = @"The quick brown fox jumped over the lazy dog\r\n";
   NSData *data = [test dataUsingEncoding:NSUTF8StringEncoding];

   [asyncSocket writeData:data withTimeout:10 tag:4];

However if I use this one then it works... but I need the NSString so I can enter a formatted string to send...

 char bytes[] = "The quick brown fox jumped over the lazy dog\r\n";
 NSData* data = [[NSData alloc] initWithBytes:bytes length:sizeof(bytes)];

 [asyncSocket writeData:data withTimeout:10 tag:4];

So what did I do wrong?

Upvotes: 1

Views: 1033

Answers (3)

Davy R
Davy R

Reputation: 39

I know its bit late but I thought it would be good to know why this works - When you call writeData method with your data buffer, the asyncsocket code creates a new object by sublassing NSObject - AsyncWritePacket using the data passed down. It then uses retain and takes ownership of the data buffer you are passing hence why you dont want to release it.

@implementation AsyncWritePacket
- (id)initWithData:(NSData *)d timeout:(NSTimeInterval)t tag:(long)i
{
    if((self = [super init]))
    {
        buffer = [d retain];
        timeout = t;
        tag = i;
        bytesDone = 0;
    }
    return self;

@end

Upvotes: 0

Mark Worsnop
Mark Worsnop

Reputation: 4467

The NSString and the NSDate were not setup with alloc and init so they were gone when they got to the write data. I changed the NSDate to alloc and init and all works well now. These idea came from the several people that answered this. thanks for the help!

Upvotes: 1

Roger
Roger

Reputation: 15813

The latter is null terminated, the former is not. This is probably the issue.

Upvotes: 0

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