ios – 通过蓝牙4.0 LE发送图像文件

我能够简单的数据,如字符串,但无法成功发送和利用图像文件.

在Peripheral设备中,我从此开始

pictureBeforeData = [UIImage imageNamed:@"myImage.png"];
NSData *myData = UIImagePNGRepresentation(pictureBeforeData);

然后我将myData作为一个特征的价值.

_myCharacteristic =
[[CBMutableCharacteristic alloc] initWithType:_myCharacteristicUUID
                                   properties:CBCharacteristicPropertyRead
                                        value:myData
                                  permissions:CBAttributePermissionsReadable];

在中央设备中,当特征的值更新时,我有这个

- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error {
  if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:_myCharacteristicUUID]]) {
    NSLog(@"PICTURE CHaraCTERISTIC FOUND"); // This successfully gets logged

    NSData *dataFromCharacteristic = [[NSData alloc] initWithData:characteristic.value];

    UIImage *imageFromData = [[UIImage alloc]initWithData:dataFromCharacteristic];

    // This correctly logs the size of my image
    NSLog(@"SIZE: %f,%f",imageFromData.size.height,imageFromData.size.width);

    // This causes the imageView to turn completely black
    _sentPictureImageView.image = imageFromData;

    if (!([_myImagesArray containsObject:imageFromData]))
    {
      NSLog(@"DOES NOT CONTAIN"); // This is successfully logged
      [_myImagesArray addobject:imageFromData]; // This runs but is apparently not adding the image to the array
    }

    NSLog(@"COUNT: %u",_contactsImagesArray.count); // This always logs 0 - The array is empty }

编辑8-27-13：我能够发送一个单一的彩色1比1像素.png文件成功的文件大约5,600字节.我无法发送只有大约2,000字节的多色20by20像素.png文件.我可以发送包含只有一种颜色和较少像素的较大文件,但无法发送包含多种颜色和更多像素的较小文件.

编辑8-30-13：我绝对必须将数据解析成较小的块.在苹果的示例项目之一中,我发现了一种方法.我似乎无法明白如何在我自己的代码中实现这一点,但是我正在试图找出如何.以下是代码：

- (void)sendData {
// First up,check if we're meant to be sending an EOM
static BOOL sendingEOM = NO;

if (sendingEOM) {

    // send it
    BOOL didSend = [self.peripheralManager updateValue:[@"EOM" dataUsingEncoding:NSUTF8StringEncoding] forCharacteristic:self.transferCharacteristic onSubscribedCentrals:nil];

    // Did it send?
    if (didSend) {

        // It did,so mark it as sent
        sendingEOM = NO;

        NSLog(@"Sent: EOM");
    }

    // It didn't send,so we'll exit and wait for peripheralManagerIsReadyToUpdateSubscribers to call sendData again
    return;
}

// We're not sending an EOM,so we're sending data

// Is there any left to send?

if (self.sendDataIndex >= self.dataToSend.length) {

    // No data left.  Do nothing
    return;
}

// There's data left,so send until the callback fails,or we're done.

BOOL didSend = YES;

while (didSend) {

    // Make the next chunk

    // Work out how big it should be
    NSInteger amountToSend = self.dataToSend.length - self.sendDataIndex;

    // Can't be longer than 20 bytes
    if (amountToSend > NOTIFY_MTU) amountToSend = NOTIFY_MTU;

    // copy out the data we want
    NSData *chunk = [NSData dataWithBytes:self.dataToSend.bytes+self.sendDataIndex length:amountToSend];

    // Send it
    didSend = [self.peripheralManager updateValue:chunk forCharacteristic:self.transferCharacteristic onSubscribedCentrals:nil];

    // If it didn't work,drop out and wait for the callback
    if (!didSend) {
        return;
    }

    Nsstring *stringFromData = [[Nsstring alloc] initWithData:chunk encoding:NSUTF8StringEncoding];
    NSLog(@"Sent: %@",stringFromData);

    // It did send,so update our index
    self.sendDataIndex += amountToSend;

    // Was it the last one?
    if (self.sendDataIndex >= self.dataToSend.length) {

        // It was - send an EOM

        // Set this so if the send fails,we'll send it next time
        sendingEOM = YES;

        // Send it
        BOOL eomSent = [self.peripheralManager updateValue:[@"EOM" dataUsingEncoding:NSUTF8StringEncoding] forCharacteristic:self.transferCharacteristic onSubscribedCentrals:nil];

        if (eomSent) {
            // It sent,we're all done
            sendingEOM = NO;

            NSLog(@"Sent: EOM");
        }

        return;
    }
}}

我的imageView是黑色的方块,它应该显示我发送的图像.