Question

我正在构建一个应用程序，其中一部分是向Firebase提交设备ID，如果提交了该设备ID，它将上传虚拟类设备状态，稍后将由NodeMCU更改和使用。但是问题是，当我创建一个数据库引用并将设备ID放在firebase上时，如果尝试将另一个addOnCompleteListener放入其中以推送虚拟设备状态类，则会出现一些错误。

我提交代码的功能和提交代码时的虚拟设备状态对象。

    void submitCode(String scannedCode){
        code=scannedCode;
        databaseReference.setValue(code).addOnCompleteListener(
                this, new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {
                        if (task.isSuccessful()){
                            DeviceStatus deviceStatus = new DeviceStatus();
                            deviceStatus.deviceID = code;
                            FirebaseDatabase.getInstance().getReference("DeviceStatus").child(code).setValue(deviceStatus).addOnCompleteListener(
                                    this, new OnCompleteListener<Void>() {
                                        @Override
                                        public void onComplete(@NonNull Task<Void> subTask) {
                                            if (subTask.isSuccessful()) {
                                                Toast.makeText(getApplicationContext(), "Product ID Successfully Entered", Toast.LENGTH_LONG).show();
                                                finish();
                                                startActivity(new Intent(getApplicationContext(), switchStatus.class));
                                            }
                                        }
                                    }
                            );

                        }
                    }
                }
        );


    }

这里的databaseReference是一个全局变量，如下：

DatabaseReference databaseReference;

并初始化为

databaseReference = FirebaseDatabase.getInstance().getReference("DeviceStatus").child(devideID);

Android Studio编辑器警告说：

Cannot resolve method 'addOnCompleteListener(anonymous com.google.android.gms.tasks.OnCompleteListener<java.lang.Void>, anonymous com.google.android.gms.tasks.OnCompleteListener<java.lang.Void>)'

构建错误提示

error: no suitable method found for addOnCompleteListener(<anonymous OnCompleteListener<Void>>,<anonymous OnCompleteListener<Void>>)
method Task.addOnCompleteListener(Executor,OnCompleteListener<Void>) is not applicable
(argument mismatch; <anonymous OnCompleteListener<Void>> cannot be converted to Executor)
method Task.addOnCompleteListener(Activity,OnCompleteListener<Void>) is not applicable
(argument mismatch; <anonymous OnCompleteListener<Void>> cannot be converted to Activity)

更新的功能：

    void submitCode(String scannedCode){
        code=scannedCode;
        databaseReference.setValue(code).addOnCompleteListener(
                this, new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {
                        if (task.isSuccessful()){
//                            sendSwitchStatus(code);
                            DeviceStatus deviceStatus = new DeviceStatus();
                            deviceStatus.deviceID = code;
                            FirebaseDatabase.getInstance().getReference("DeviceStatus").child(code).setValue(deviceStatus).addOnCompleteListener( getBaseContext(), new OnCompleteListener<Void>(){


                                public void onComplete(@Nullable Task<void> subTask){
                                    if (subTask.isSuccessful()) {
                                        Toast.makeText(getApplicationContext(), "Product ID Successfully Registered", Toast.LENGTH_LONG).show();
                                        finish();
                                        startActivity(new Intent(getApplicationContext(), switchStatus.class));
                                    }
                                }


                            });

                        }
                    }
                }
        );
    }

Answer 1

在第二次设置addOnCompleteListener时使用活动上下文。

public class MainActivity extends AppCompatActivity {
    private int toggle = 0;
    DatabaseReference databaseReference;
    Activity activity;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        activity = this;
        databaseReference = FirebaseDatabase.getInstance().getReference("DeviceStatus").child("");
    }
    void submitCode(String scannedCode){
        String code = scannedCode;
        databaseReference.setValue(code).addOnCompleteListener(this, new OnCompleteListener<Void>() {
            @Override
            public void onComplete(@NonNull Task<Void> task) {
                FirebaseDatabase.getInstance().getReference("DeviceStatus").child("").setValue("").addOnCompleteListener(activity, new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {

                    }
                });
            }
        });
    }
}

由于对Activity的引用有些困惑，因此我写了一些与您的示例代码类似的示例代码（仅将示例中的某些变量替换为“”）。请检查并随时询问任何进一步的信息。

Firebase的Onclick侦听器嵌套无法正常工作

1 个答案: