真正的iPhone上的NSInputStream问题

Question

I have a problem with NSInputStream. Here is my code:

case NSStreamEventHasBytesAvailable:

        printf("BYTE AVAILABLE\n");

        int len = 0;
        NSMutableData *data = [[NSMutableData alloc] init];

        uint8_t buffer[32768];

        if(stream == iStream)
        {       
            printf("Receiving...\n");                       

            len = [iStream read:buffer maxLength:32768];                

            [data appendBytes:buffer length:len];                   

        } 
        [iStream close];

I try to read small data and it works perfectly on simulator and real iPhone. If I try to read large data (more than 4kB or maybe 5kB), the real iPhone just can read 2736 bytes and stop.

Why is it? Help me plz! Merci d'avance!

Answer 1

Your data object needs to be external to your stream handler. It is often the case that when large abounts of data are coming in, you get it in chunks and not all at once. Just keep appending data to it until you receive bytesRead == 0; Then you can close your stream and use the data.

   case NSStreamEventHasBytesAvailable: {
        NSInteger       bytesRead;
        uint8_t         buffer[32768];

        // Pull some data off the network.

        bytesRead = [self._networkStream read:buffer maxLength:sizeof(buffer)];

        if (bytesRead == -1) {
            [self _stopReceiveWithFailure];
        } else if (bytesRead == 0) {
            [self _stopReceiveWithSuccess];
        } else {
            [data appendBytes:buffer length:len];                   
        }

Answer 2

看起来您每次都在创建一个新的data对象……也许您应该将其创建并保留为一个属性，然后像上面一样附加到该对象。