一个小案例演示获取手机，sd卡的总内存和可用内存。

案例：

  1. 一个 TextView显示
  2. MainActivity
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public class MainActivity extends AppCompatActivity {
    private TextView text;

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

        text = (TextView)findViewById(R.id.tv_text);

        //获得sd卡的内存状态
        File sdFile = Environment.getExternalStorageDirectory();
        String sdcardMemory = getMemoryIfno(sdFile);

        //获得手机的内存状态
        File file = Environment.getDataDirectory();
        String dataMemory = getMemoryIfno(file);

        text.setText("sd卡:" + sdcardMemory + "\n" + "手机内存:"  +dataMemory);

    }

    private String getMemoryIfno(File path){

        //获得磁盘状态对象 ,并传入路径
        StatFs statFs = new StatFs(path.getPath());
        long blookSize = statFs.getBlockSizeLong(); //获得单个磁盘扇区大小
        long blockCount = statFs.getBlockCountLong();//获得扇区总数
        long availableBlock = statFs.getAvailableBlocksLong();//获得可用扇区数量

        String totalMeory = Formatter.formatFileSize(this, blookSize * blockCount);  //总空间
        String avaiableMemory = Formatter.formatFileSize(this, blookSize * availableBlock); //可用空间



        return "总共内存为" +totalMeory  + "\n" + "可用内存为" + avaiableMemory;

    }
}

image.png

获取位置
Android 中获取用户地理位置的操作。

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<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"></uses-permission>
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public class MainActivity extends AppCompatActivity {
    private TextView tv_view ;
    private LocationManager locationManager ;
    private String provider ;

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

        tv_view = (TextView) findViewById(R.id.tv_view);

        //获取LocationManager实例
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        //获取可用的位置提供器
        List<String> providerList = locationManager.getProviders(true);

        if (providerList.contains(LocationManager.GPS_PROVIDER)) {
            provider = LocationManager.GPS_PROVIDER;
        } else if (provider.contains(LocationManager.NETWORK_PROVIDER)) {
            provider = LocationManager.NETWORK_PROVIDER;
        } else {
            Toast.makeText(this, "没有位置提供可用", Toast.LENGTH_SHORT).show();

            return;
        }

        Location location = locationManager.getLastKnownLocation(provider);
        if (location != null) {

            //显示当前设备位置信息
            showLocation(location);
        }
        //位置改变改的方法
        locationManager.requestLocationUpdates(provider, 5000, 1, locationListener);

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if(locationManager != null) {
            locationManager.removeUpdates(locationListener);
        }
    }
    LocationListener locationListener = new LocationListener() {
        @Override
        public void onLocationChanged(Location location) {

            //显示当前设备位置信息
            showLocation(location);

        }

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {

        }

        @Override
        public void onProviderEnabled(String provider) {

        }

        @Override
        public void onProviderDisabled(String provider) {

        }
        };
    private void showLocation(Location location){
        String currentPosition = "latitude is" +location.getLatitude() +"\n" +"longitude is" +location.getLongitude();
        
        //显示在TextView上
        tv_view.setText(currentPosition);
    }
}