如何改变使用核心蓝牙ios扫描外围设备时发现的特征顺序

Question

我在ios中使用核心蓝牙框架并扫描和发现2个特征ID，但我希望他们的订单与我得到的不同，那么是否有可能以编程方式更改订单或任何内容？

代码

   if (service.UUID.isEqual(CBUUID.UUIDWithString("F4F2-BC76-3206341A")))
    {
        println(service.characteristics.count)
        for aChar:CBCharacteristic in service.characteristics as [CBCharacteristic]

        {
            println(aChar)
            println(aChar.UUID)

            /* Write data*/
            if aChar.UUID.isEqual(CBUUID.UUIDWithString("D0F0AECD-6405-0B040047"))
            {
                var str:NSString = "heyaa..!!"
                data = str.dataUsingEncoding(NSUTF8StringEncoding)!
                peripheral.writeValue(data, forCharacteristic: aChar, type: CBCharacteristicWriteType.WithResponse)
                println("Write performed")
            }

            /* read data  */
            if aChar.UUID.isEqual(CBUUID.UUIDWithString("C8853E-A248-C6F0B1"))
            {
                peripheral.readValueForCharacteristic(aChar)
                println("Read performed")
            }
        }
    }

在这个特性中，首先调用用于读取数据的ID，但我想首先调用写入数据特征ID，以便有任何解决方法。请帮帮我。提前谢谢。

Answer 1

特征将以任意和未定义的顺序发现，但这不重要。

您应该存储对已发现特征的引用，以便您可以根据需要写入它们。

你应用应该经历不同的阶段

1. 扫描并发现广告特定服务的外围设备
2. 连接目标外设
3. 了解服务的特征
4. 根据需要读取/写入数据 - 根据需要重复此步骤
5. 断开

例如：

    var writeCharacteristic : CBCharacteristic?
    var readCharacteristic : CBCharacteristic?

    optional func peripheral(_ peripheral: CBPeripheral!, didDiscoverCharacteristicsForService service: CBService!,error error: NSError!) {    

      if (service.UUID.isEqual(CBUUID.UUIDWithString("F4F2-BC76-3206341A"))) 
      {

        println(service.characteristics.count)
        for aChar:CBCharacteristic in service.characteristics as [CBCharacteristic]

        {
            println(aChar)
            println(aChar.UUID)

            /* Write data*/
            if aChar.UUID.isEqual(CBUUID.UUIDWithString("D0F0AECD-6405-0B040047"))
            {
                self.writeCharacteristic=aChar
            }
            else if aChar.UUID.isEqual(CBUUID.UUIDWithString("C8853E-A248-C6F0B1"))
            {
                self.readCharacteristic=aChar

            }
        }
      }
      if (self.writeCharacteristic != nil && self.readCharacteristic != nil) {
            var str:NSString = "heyaa..!!"
            data = str.dataUsingEncoding(NSUTF8StringEncoding)!
            peripheral.writeValue(data, forCharacteristic: self.writeCharacteristic!, type: CBCharacteristicWriteType.WithResponse)
            println("Write performed")
      }
    }

    optional func peripheral(_ peripheral: CBPeripheral!,didWriteValueForCharacteristic characteristic: CBCharacteristic!,error error: NSError!) {
       peripheral.readValueForCharacteristic(self.readCharacteristic!)
       println("Read performed")
    }