为什么我的选择设备活动不运行？

Question

我一直在通过 android studio 制作应用程序。该应用程序的理念是它通过蓝牙从 arduino 获取数据并将该数据显示给用户。 但是我为选择设备活动创建的 Java 类是启动它的一个，它没有运行。我已经使用 logcat 进行了检查。 ` 我还在 github 上发布了我的所有代码：https://github.com/OtakuDisease/Hivey 这是 SelectDeviceActivity.java 类。

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.DefaultItemAnimator;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.os.Bundle;
import android.view.View;

import com.example.hivey.ui.DeviceInfoModel;
import com.example.hivey.ui.DeviceListAdapter;
import com.google.android.material.snackbar.Snackbar;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;

public class SelectDeviceActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_select_device);
        // Bluetooth Setup
        BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

        // Get List of Paired Bluetooth Device
        Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices();
        List<Object> deviceList = new ArrayList<>();
        if (pairedDevices.size() > 0) {
            // There are paired devices. Get the name and address of each paired device.
            for (BluetoothDevice device : pairedDevices) {
                String deviceName = device.getName();
                String deviceHardwareAddress = device.getAddress(); // MAC address
                DeviceInfoModel deviceInfoModel = new DeviceInfoModel(deviceName,deviceHardwareAddress);
                deviceList.add(deviceInfoModel);
            }
            // Display paired device using recyclerView
            RecyclerView recyclerView = findViewById(R.id.recyclerViewDevice);
            recyclerView.setLayoutManager(new LinearLayoutManager(this));
            DeviceListAdapter deviceListAdapter = new DeviceListAdapter(this,deviceList);
            recyclerView.setAdapter(deviceListAdapter);
            recyclerView.setItemAnimator(new DefaultItemAnimator());
        } else {
            View view = findViewById(R.id.recyclerViewDevice);
            Snackbar snackbar = Snackbar.make(view, "Activate Bluetooth or pair a Bluetooth device", Snackbar.LENGTH_INDEFINITE);
            snackbar.setAction("OK", new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                }
            });
            snackbar.show();
        }
    }
}

Answer 1

你能把 logcat 错误发给你吗？ 可能是空指针异常（可能，不是sur）