为什么Gatt Characteristic设置Value Changed时值不在预期范围内
Why value does not fall within the expected range when setting Value Changed for Gatt Characteristic
我想继续阅读 characteristic/set 我的 BLE 4.0 设备特性的值更改事件处理程序，方法是在 Visual Studio 2017 中使用 Universal Windows Platform C# 中的 ValueChanged 回调.
我遵循了这些站点的一些教程：Damian Blog's Windows Universal with BLE, Bluetooth Gatt's Git Hub, Bluetooth Generic Attribute Profile - Heart Rate Service and Dr. Jukka's mobile Blog on BLE。他们都在使用 ValueChanged，我也尝试按照他们所做的去做。
不幸的是，我没有触发 ValueChanged，而是在使用 ValueChanged 回调时收到以下错误。
System.ArgumentException: 'Value does not fall within the expected range.'
这行代码产生错误：
characteristic.ValueChanged += Oncharacteristic_ValueChanged;
这里是我的源代码的更多细节：
注意：我正在为我的加密狗使用 COM 7，我的程序可以发现 BLE 的设备名称，并且可以发现服务和特征的 Uuid。
public List<string> serviceList = new List<string>();
public List<string> characteristicList = new List<string>();
public BluetoothLEDevice myDevice { get; set; }
public MainPage()
{
this.InitializeComponent();
}
private async void Page_Loaded(object sender, RoutedEventArgs e)
{
// Find the com port
string selector = SerialDevice.GetDeviceSelector("COM7");
DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(selector);
if (devices.Count > 0)
{
var dialog = new MessageDialog("Com Device found");
await dialog.ShowAsync();
DeviceInformation deviceInfo = devices[0];
SerialDevice serialDevice = await SerialDevice.FromIdAsync(deviceInfo.Id);
serialDevice.BaudRate = 9600;
serialDevice.DataBits = 8;
serialDevice.StopBits = SerialStopBitCount.One;
serialDevice.Parity = SerialParity.None;
}
else
{
MessageDialog popup = new MessageDialog("Sorry, no device found.");
await popup.ShowAsync();
}
// After com port is found, search for device
foreach (DeviceInformation di in await DeviceInformation.FindAllAsync(BluetoothLEDevice.GetDeviceSelector()))
{
BluetoothLEDevice bleDevice = await BluetoothLEDevice.FromIdAsync(di.Id);
// Display BLE device name
var dialogBleDeviceName = new MessageDialog("BLE Device Name " + bleDevice.Name);
await dialogBleDeviceName.ShowAsync();
myDevice = bleDevice;
}
// Check device connection
myDevice.ConnectionStatusChanged += OnConnectionStatusChanged;
foreach (var service in myDevice.GattServices)
{
serviceList.Add(service.Uuid.ToString());
// Verify if service is discovered by displaying a popup
MessageDialog serviceUuidPopUp = new MessageDialog("Adding Service Uuid to list " + service.Uuid.ToString() );
await serviceUuidPopUp.ShowAsync();
foreach (var characteristic in service.GetAllCharacteristics())
{
var characteristicUuid = characteristic.Uuid.ToString().ToLowerInvariant();
characteristicList.Add(characteristicUuid);
// Verify if characteristic is discovered by displaying a popup
MessageDialog charUuidPopUp = new MessageDialog("Adding characteristic Uuid to list " + characteristicUuid);
await charUuidPopUp.ShowAsync();
// set value changed event handlers for characteristics
characteristic.ValueChanged += Oncharacteristic_ValueChanged;
}
}
}
private void OnConnectionStatusChanged(BluetoothLEDevice sender, object args)
{
if (sender.ConnectionStatus == BluetoothConnectionStatus.Connected)
{
System.Diagnostics.Debug.WriteLine("Connected");
}
else
{
System.Diagnostics.Debug.WriteLine("Disconnected");
}
}
private void Oncharacteristic_ValueChanged(GattCharacteristic sender, GattValueChangedEventArgs args)
{
byte[] data = new byte[args.CharacteristicValue.Length];
DataReader.FromBuffer(
args.CharacteristicValue).ReadBytes(data);
string text = Encoding.UTF8.GetString(data, 0, data.Length);
}
更新 1
我尝试按照 answer given by rudi belt on SO.
在为我的特征设置值更改事件处理程序之前检查特征属性
if (characteristic.CharacteristicProperties == (GattCharacteristicProperties.Read | GattCharacteristicProperties.Notify))
{
characteristic.ValueChanged += Oncharacteristic_ValueChanged;
}
很遗憾，这个 IF 语句没有被执行。
更新 2
我试图删除 ALL Oncharacteristic_ValueChanged 方法中的代码。但它仍然给我同样的错误
System.ArgumentException: 'Value does not fall within the expected range.'
我花了很多时间试图解决这个问题。如果有人可以帮助我，我将非常高兴。谢谢！
阅读您在前一个问题中所做的努力，我可以提供一个工作示例，但首先要进行一些解释。
myDevice.ConnectionStatusChanged 不需要，它仅用于通知连接丢失或已连接。您必须先连接到您的设备并在连接方法中处理事情。
连接成功后，您必须获取包含您要用于读取、写入、通知或指示的特征的服务。
当您选择了服务后，您可以获得该服务的特征。
Select Uuid 的特征，或者在我的例子中 CharacteristicProperties.HasFlag。
在我的例子中这个标志是 Notify。
在代码注释中，您可以找到额外的信息。
using System;
using System.Diagnostics;
using System.Threading.Tasks;
using Windows.Devices.Bluetooth;
using Windows.Devices.Bluetooth.GenericAttributeProfile;
using Windows.Devices.Enumeration;
using Windows.UI.Popups;
using Windows.UI.Xaml.Controls;
namespace App1
{
public sealed partial class MainPage : Page
{
GattDeviceServicesResult serviceResult = null;
private BluetoothLEDevice myDevice;
private GattCharacteristic selectedCharacteristic;
public MainPage()
{
this.InitializeComponent();
ConnectDevice();
}
private async void ConnectDevice()
{
//This works only if your device is already paired!
foreach (DeviceInformation di in await DeviceInformation.FindAllAsync(BluetoothLEDevice.GetDeviceSelector()))
{
BluetoothLEDevice bleDevice = await BluetoothLEDevice.FromIdAsync(di.Id);
// Display BLE device name
var dialogBleDeviceName = new MessageDialog("BLE Device Name " + bleDevice.Name);
await dialogBleDeviceName.ShowAsync();
myDevice = bleDevice;
}
if (myDevice != null)
{
int servicesCount = 3;//Fill in the amount of services from your device!!!!!
int tryCount = 0;
bool connected = false;
while (!connected)//This is to make sure all services are found.
{
tryCount++;
serviceResult = await myDevice.GetGattServicesAsync();
if (serviceResult.Status == GattCommunicationStatus.Success && serviceResult.Services.Count >= servicesCount)
{
connected = true;
Debug.WriteLine("Connected in " + tryCount + " tries");
}
if (tryCount > 5)//make this larger if faild
{
Debug.WriteLine("Failed to connect to device ");
return;
}
}
if (connected)
{
for (int i = 0; i < serviceResult.Services.Count; i++)
{
var service = serviceResult.Services[i];
//This must be the service that contains the Gatt-Characteristic you want to read from or write to !!!!!!!.
string myServiceUuid = "0000ffe0-0000-1000-8000-00805f9b34fb";
if (service.Uuid.ToString() == myServiceUuid)
{
Get_Characteriisics(service);
break;
}
}
}
}
}
private async void Get_Characteriisics(GattDeviceService myService)
{
var CharResult = await myService.GetCharacteristicsAsync();
if (CharResult.Status == GattCommunicationStatus.Success)
{
foreach (GattCharacteristic c in CharResult.Characteristics)
{
if (c.CharacteristicProperties.HasFlag(GattCharacteristicProperties.Notify))
{
selectedCharacteristic = c;
break;
}
}
try
{
// Write the ClientCharacteristicConfigurationDescriptor in order for server to send notifications.
var result = await selectedCharacteristic.WriteClientCharacteristicConfigurationDescriptorAsync(
GattClientCharacteristicConfigurationDescriptorValue.Notify);
if (result == GattCommunicationStatus.Success)
{
var dialogNotifications = new MessageDialog("Successfully registered for notifications");
await dialogNotifications.ShowAsync();
selectedCharacteristic.ValueChanged += SelectedCharacteristic_ValueChanged;
}
else
{
var dialogNotifications = new MessageDialog($"Error registering for notifications: {result}");
await dialogNotifications.ShowAsync();
}
}
catch (Exception ex)
{
// This usually happens when not all characteristics are found
// or selected characteristic has no Notify.
var dialogNotifications = new MessageDialog(ex.Message);
await dialogNotifications.ShowAsync();
await Task.Delay(100);
Get_Characteriisics(myService); //try again
//!!! Add a max try counter to prevent infinite loop!!!!!!!
}
}
else
{
var dialogNotifications = new MessageDialog("Restricted service. Can't read characteristics");
await dialogNotifications.ShowAsync();
}
}
private void SelectedCharacteristic_ValueChanged(GattCharacteristic sender, GattValueChangedEventArgs args)
{
}
}
}
如果您对此代码有任何疑问，请随时在评论中提问。
我想继续阅读 characteristic/set 我的 BLE 4.0 设备特性的值更改事件处理程序，方法是在 Visual Studio 2017 中使用 Universal Windows Platform C# 中的 ValueChanged 回调.
我遵循了这些站点的一些教程：Damian Blog's Windows Universal with BLE, Bluetooth Gatt's Git Hub, Bluetooth Generic Attribute Profile - Heart Rate Service and Dr. Jukka's mobile Blog on BLE。他们都在使用 ValueChanged，我也尝试按照他们所做的去做。
不幸的是，我没有触发 ValueChanged，而是在使用 ValueChanged 回调时收到以下错误。
System.ArgumentException: 'Value does not fall within the expected range.'
这行代码产生错误：
characteristic.ValueChanged += Oncharacteristic_ValueChanged;
这里是我的源代码的更多细节：
注意：我正在为我的加密狗使用 COM 7，我的程序可以发现 BLE 的设备名称，并且可以发现服务和特征的 Uuid。
public List<string> serviceList = new List<string>();
public List<string> characteristicList = new List<string>();
public BluetoothLEDevice myDevice { get; set; }
public MainPage()
{
this.InitializeComponent();
}
private async void Page_Loaded(object sender, RoutedEventArgs e)
{
// Find the com port
string selector = SerialDevice.GetDeviceSelector("COM7");
DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(selector);
if (devices.Count > 0)
{
var dialog = new MessageDialog("Com Device found");
await dialog.ShowAsync();
DeviceInformation deviceInfo = devices[0];
SerialDevice serialDevice = await SerialDevice.FromIdAsync(deviceInfo.Id);
serialDevice.BaudRate = 9600;
serialDevice.DataBits = 8;
serialDevice.StopBits = SerialStopBitCount.One;
serialDevice.Parity = SerialParity.None;
}
else
{
MessageDialog popup = new MessageDialog("Sorry, no device found.");
await popup.ShowAsync();
}
// After com port is found, search for device
foreach (DeviceInformation di in await DeviceInformation.FindAllAsync(BluetoothLEDevice.GetDeviceSelector()))
{
BluetoothLEDevice bleDevice = await BluetoothLEDevice.FromIdAsync(di.Id);
// Display BLE device name
var dialogBleDeviceName = new MessageDialog("BLE Device Name " + bleDevice.Name);
await dialogBleDeviceName.ShowAsync();
myDevice = bleDevice;
}
// Check device connection
myDevice.ConnectionStatusChanged += OnConnectionStatusChanged;
foreach (var service in myDevice.GattServices)
{
serviceList.Add(service.Uuid.ToString());
// Verify if service is discovered by displaying a popup
MessageDialog serviceUuidPopUp = new MessageDialog("Adding Service Uuid to list " + service.Uuid.ToString() );
await serviceUuidPopUp.ShowAsync();
foreach (var characteristic in service.GetAllCharacteristics())
{
var characteristicUuid = characteristic.Uuid.ToString().ToLowerInvariant();
characteristicList.Add(characteristicUuid);
// Verify if characteristic is discovered by displaying a popup
MessageDialog charUuidPopUp = new MessageDialog("Adding characteristic Uuid to list " + characteristicUuid);
await charUuidPopUp.ShowAsync();
// set value changed event handlers for characteristics
characteristic.ValueChanged += Oncharacteristic_ValueChanged;
}
}
}
private void OnConnectionStatusChanged(BluetoothLEDevice sender, object args)
{
if (sender.ConnectionStatus == BluetoothConnectionStatus.Connected)
{
System.Diagnostics.Debug.WriteLine("Connected");
}
else
{
System.Diagnostics.Debug.WriteLine("Disconnected");
}
}
private void Oncharacteristic_ValueChanged(GattCharacteristic sender, GattValueChangedEventArgs args)
{
byte[] data = new byte[args.CharacteristicValue.Length];
DataReader.FromBuffer(
args.CharacteristicValue).ReadBytes(data);
string text = Encoding.UTF8.GetString(data, 0, data.Length);
}
更新 1 我尝试按照 answer given by rudi belt on SO.
在为我的特征设置值更改事件处理程序之前检查特征属性if (characteristic.CharacteristicProperties == (GattCharacteristicProperties.Read | GattCharacteristicProperties.Notify))
{
characteristic.ValueChanged += Oncharacteristic_ValueChanged;
}
很遗憾，这个 IF 语句没有被执行。
更新 2 我试图删除 ALL Oncharacteristic_ValueChanged 方法中的代码。但它仍然给我同样的错误
System.ArgumentException: 'Value does not fall within the expected range.'
我花了很多时间试图解决这个问题。如果有人可以帮助我，我将非常高兴。谢谢！
阅读您在前一个问题中所做的努力，我可以提供一个工作示例，但首先要进行一些解释。 myDevice.ConnectionStatusChanged 不需要，它仅用于通知连接丢失或已连接。您必须先连接到您的设备并在连接方法中处理事情。
连接成功后，您必须获取包含您要用于读取、写入、通知或指示的特征的服务。
当您选择了服务后，您可以获得该服务的特征。
Select Uuid 的特征，或者在我的例子中 CharacteristicProperties.HasFlag。 在我的例子中这个标志是 Notify。 在代码注释中，您可以找到额外的信息。
using System;
using System.Diagnostics;
using System.Threading.Tasks;
using Windows.Devices.Bluetooth;
using Windows.Devices.Bluetooth.GenericAttributeProfile;
using Windows.Devices.Enumeration;
using Windows.UI.Popups;
using Windows.UI.Xaml.Controls;
namespace App1
{
public sealed partial class MainPage : Page
{
GattDeviceServicesResult serviceResult = null;
private BluetoothLEDevice myDevice;
private GattCharacteristic selectedCharacteristic;
public MainPage()
{
this.InitializeComponent();
ConnectDevice();
}
private async void ConnectDevice()
{
//This works only if your device is already paired!
foreach (DeviceInformation di in await DeviceInformation.FindAllAsync(BluetoothLEDevice.GetDeviceSelector()))
{
BluetoothLEDevice bleDevice = await BluetoothLEDevice.FromIdAsync(di.Id);
// Display BLE device name
var dialogBleDeviceName = new MessageDialog("BLE Device Name " + bleDevice.Name);
await dialogBleDeviceName.ShowAsync();
myDevice = bleDevice;
}
if (myDevice != null)
{
int servicesCount = 3;//Fill in the amount of services from your device!!!!!
int tryCount = 0;
bool connected = false;
while (!connected)//This is to make sure all services are found.
{
tryCount++;
serviceResult = await myDevice.GetGattServicesAsync();
if (serviceResult.Status == GattCommunicationStatus.Success && serviceResult.Services.Count >= servicesCount)
{
connected = true;
Debug.WriteLine("Connected in " + tryCount + " tries");
}
if (tryCount > 5)//make this larger if faild
{
Debug.WriteLine("Failed to connect to device ");
return;
}
}
if (connected)
{
for (int i = 0; i < serviceResult.Services.Count; i++)
{
var service = serviceResult.Services[i];
//This must be the service that contains the Gatt-Characteristic you want to read from or write to !!!!!!!.
string myServiceUuid = "0000ffe0-0000-1000-8000-00805f9b34fb";
if (service.Uuid.ToString() == myServiceUuid)
{
Get_Characteriisics(service);
break;
}
}
}
}
}
private async void Get_Characteriisics(GattDeviceService myService)
{
var CharResult = await myService.GetCharacteristicsAsync();
if (CharResult.Status == GattCommunicationStatus.Success)
{
foreach (GattCharacteristic c in CharResult.Characteristics)
{
if (c.CharacteristicProperties.HasFlag(GattCharacteristicProperties.Notify))
{
selectedCharacteristic = c;
break;
}
}
try
{
// Write the ClientCharacteristicConfigurationDescriptor in order for server to send notifications.
var result = await selectedCharacteristic.WriteClientCharacteristicConfigurationDescriptorAsync(
GattClientCharacteristicConfigurationDescriptorValue.Notify);
if (result == GattCommunicationStatus.Success)
{
var dialogNotifications = new MessageDialog("Successfully registered for notifications");
await dialogNotifications.ShowAsync();
selectedCharacteristic.ValueChanged += SelectedCharacteristic_ValueChanged;
}
else
{
var dialogNotifications = new MessageDialog($"Error registering for notifications: {result}");
await dialogNotifications.ShowAsync();
}
}
catch (Exception ex)
{
// This usually happens when not all characteristics are found
// or selected characteristic has no Notify.
var dialogNotifications = new MessageDialog(ex.Message);
await dialogNotifications.ShowAsync();
await Task.Delay(100);
Get_Characteriisics(myService); //try again
//!!! Add a max try counter to prevent infinite loop!!!!!!!
}
}
else
{
var dialogNotifications = new MessageDialog("Restricted service. Can't read characteristics");
await dialogNotifications.ShowAsync();
}
}
private void SelectedCharacteristic_ValueChanged(GattCharacteristic sender, GattValueChangedEventArgs args)
{
}
}
}
如果您对此代码有任何疑问，请随时在评论中提问。