安卓作業----慕課移動應用開發作業17之通過BroadcastReceiver模擬手機電量查看

本篇通過BroadcastReceiver模擬手機電量查看，通過AlertDialog進行電量信息提示

同時這也是中國大學慕課移動終端應用開發的網課作業17，我會持續更新我的作業，如果有需要關注一下吧

學習建議

1.Broadcast有關知識可看：Android 之 超詳細 Broadcast

2.瞭解Intent.ACTION_BATTERY_CHANGED中攜帶數據可看：監聽電池變化的廣播中攜帶的數據

3.常用Intent可看：android 系統Intent合集

效果圖

代碼實現

MyReceiver.java

public class MyReceiver extends BroadcastReceiver {
    private int level;//保存電量的值

    @Override
    public void onReceive(Context context, Intent intent) {
        //獲取電量信息並保存
        int level = intent.getIntExtra("level", 0);
        this.level = level;
    }

    public int getLevel() {
        return level;
    }

    public void setLevel(int level) {
        this.level = level;
    }
}

MainActivity.java

public class MainActivity extends AppCompatActivity {
    private Button mButton;
    private MyReceiver mReceiver;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mButton = findViewById(R.id.send);

        //設置過濾器
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(Intent.ACTION_BATTERY_CHANGED);
        mReceiver = new MyReceiver();
        //動態註冊
        registerReceiver(mReceiver, intentFilter);

        //給按鈕添加彈出對話框事件
        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                AlertDialog.Builder d = new AlertDialog.Builder(MainActivity.this);
                d.setTitle("系統提示")
                        .setMessage("當前剩餘電量低於"+mReceiver.getLevel()+"%,請及時充電")//獲取電量這個屬性
                        .setIcon(R.mipmap.ic_launcher)
                        .setPositiveButton("確定", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(MainActivity.this,"點擊了確定",Toast.LENGTH_SHORT).show();
                            }
                        })
                        .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(MainActivity.this,"點擊了取消",Toast.LENGTH_SHORT).show();
                            }
                        })
                        .setNeutralButton("忽略", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(MainActivity.this,"點擊了忽略",Toast.LENGTH_SHORT).show();

                            }
                        });
                d.create().show();
            }
        });

    }


}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
<Button
    android:id="@+id/send"
    android:text="查看電量"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"/>


</LinearLayout>

總結

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