HarmonyOS 鸿蒙Next 蓝牙功能写入操作writeCharacteristicValue遇Error: BussinessError 401 Invalid parameter

试一下这个呢？

writeCharacteristicValue() {
 if (!this.gattServiceInfo) {
   this.characteristicValue = '';
   console.log('BluetoothPage bluetooth gattServiceInfo is undefined ');
   return
 }
 let services: ble.GattService = this.gattServiceInfo;
 let descriptors: Array<ble.BLEDescriptor> = [];
 let descriptor: ble.BLEDescriptor = {
   serviceUuid: services.serviceUuid,
   characteristicUuid: services.characteristics[0].characteristicUuid,
   descriptorUuid: services.characteristics[0].descriptors[0].descriptorUuid,
   descriptorValue: services.characteristics[0].descriptors[0].descriptorValue
 };
 descriptors[0] = descriptor;
 let value : string = ''
 let characteristic: ble.BLECharacteristic = {
   serviceUuid: services.serviceUuid,
   characteristicUuid: services.characteristics[0].characteristicUuid,
   characteristicValue: Utils.string2ArrayBuffer(this.cValue),
   descriptors: descriptors,
 };
 try {
   if (this.gattClient) {
     this.gattClient.writeCharacteristicValue(characteristic, ble.GattWriteType.WRITE);
     promptAction.showToast({
       message: '特征值写结束'
     })
     console.log('BluetoothPage writeCharacteristicValue finish');
   }
 } catch (err) {
   console.error('errCode: ' + (err as BusinessError).code + ', errMessage: ' + (err as BusinessError).message);
 }
}
string2ArrayBuffer(value: string) {
 let buf = buffer.from(value,'utf16le').buffer;
 return buf;
}