java - Android Studio 如何在手机锁定时从音量按钮获取信息？

Question

                    I am having some problem with getting information from volume buttons while the phone is locked can someone tell me how to do it with a good example(I am beginner)

我一直在寻找其他一些讨论，但它们并没有解决我的问题。

package com.example.android.app1;

// 我知道其中一些导入甚至没有做任何事情，只是不介意那些

                import android.content.Context;
                import android.os.Bundle;
                import android.os.Vibrator;
                import android.support.v7.app.AppCompatActivity;
                import android.view.KeyEvent;
                import android.view.View;
                import java.lang.Object;
                import android.widget.TextView;

                public class MainActivity extends AppCompatActivity {
                    int number = 0;



                    @Override
                    protected void onCreate(Bundle savedInstanceState) {
                        super.onCreate(savedInstanceState);
                        setContentView(R.layout.activity_main);
                    }

//问题出在这里我想在手机锁定时使用此代码

                    @Override
                    public boolean onKeyUp(int keyCode, KeyEvent event) {
                        if ((keyCode == KeyEvent.KEYCODE_VOLUME_UP)) {

**

    > //Vibrates when they press volume key and adds

    **

                            Vibrator v = (Vibrator) 
                            getSystemService(Context.VIBRATOR_SERVICE);
                            number++;
                            v.vibrate(50);
                            display(number);
                        }
                        if ((keyCode == KeyEvent.KEYCODE_VOLUME_DOWN)) {
                            Vibrator v = (Vibrator) 

//同样在这里我不知道该写什么，因为我告诉过你我是新手，我想知道如何在手机锁定时使用此代码谢谢。***

                            getSystemService(Context.VIBRATOR_SERVICE);
                            number--;
                            display(number);
                            v.vibrate(150);
                        }
                        return true;
                    }

    >      ***//In here it adds the number when they press the button on the screen
    >     
    >     ***

                    public void add(View view) {
                        number++;
                        display(number);

                    }

                    public void minus(View view) {
                        number--;
                        display(number);
                    }

                    public void display(int number) {
                        TextView numberView = (TextView) 
                        findViewById(R.id.nmt);
                        numberView.setText(String.valueOf(number));
                    }

                }

标签： javaandroidxmlandroid-studio