android开发app源码

Android开发App源码是指按照Java编写规则和Android应用程序开发的规范开发的Android移动应用程序的代码文件。Android平台的应用程序开发通常采用Java语言、Android SDK和Eclipse等开发工具。下面就以一个跑步记录App为例,介绍Android开发App源码。

1. 创建新项目

打开Android Studio,点击"Create New Project"按钮,输入项目名称和包名,选择最低支持Android版本和手机屏幕尺寸,选择Empty Activity模板,点击Next按钮。

2. 设置变量和布局文件

在MainActivity.java中,定义Activity布局文件所包含的TextView和ListView对象:

```java

TextView distanceTextView;

TextView timeTextView;

TextView speedTextView;

ListView timeList;

ArrayAdapter adapter;

ArrayList arrayList;

```

3. 实现计时器功能

使用android.os.CountDownTimer类实现计时器的功能,定义以下成员变量:

```java

private CountDownTimer countDownTimer;

private String time = ""

private long timeSpent;

```

在onCreate()方法中初始化计时器、设置计时时间和计时完成后执行的操作:

```java

countDownTimer = new CountDownTimer(MAX_TIME_MILLIS, 1000) {

@Override

public void onTick(long millisUntilFinished) {

timeSpent += 1000;

time = DateUtils.formatElapsedTime(timeSpent / 1000);

timeTextView.setText(String.format("%s %s", getString(R.string.time_num), time));

}

@Override

public void onFinish() {

timeTextView.setVisibility(View.GONE);

}

};

```

4. 添加定位功能

使用Android的LocationManager,在AndroidManifest.xml添加定位的权限:

```xml

```

在MainActivity.java中定义以下成员变量:

```java

private static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;

private LocationManager locationManager;

private LocationListener locationListener;

private Location currentLocation;

```

在onCreate()方法中获取定位权限并注册Listener:

```java

locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

locationListener = new LocationListener() {

@Override

public void onLocationChanged(Location location) {

currentLocation = location;

distanceTextView.setText(String.format("%s %s", getString(R.string.distance_num), String.valueOf(distance)));

speedTextView.setText(String.format("%s %s", getString(R.string.speed_num), String.valueOf(speed)));

}

@Override

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

}

@Override

public void onProviderEnabled(String provider) {

}

@Override

public void onProviderDisabled(String provider) {

}

};

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, MY_PERMISSIONS_REQUEST_LOCATION);

} else {

locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);

}

} else {

locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);

}

```

5. 实现ListView

在onCreate()方法中实现ListView:

```java

arrayList = new ArrayList();

adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, arrayList);

timeList.setAdapter(adapter);

```

在LocationListener回调方法中,添加记录行走距离和更新速度的功能:

```java

if (currentLocation != null) {

float[] results = new float[1];

Location.distanceBetween(previousLocation.getLatitude(), previousLocation.getLongitude(),

currentLocation.getLatitude(), currentLocation.getLongitude(), results);

float distanceInMeters = results[0];

distance += distanceInMeters;

speed = currentLocation.getSpeed();

previousLocation = currentLocation;

arrayList.add(time + "\n" + String.format("%s %.2f km", getString(R.string.distance_num), distance / 1000) + "\n" + String.format("%s %.2f km/h", getString(R.string.speed_num), (speed * 3600) / 1000));

adapter.notifyDataSetChanged();

}

```

以上就是跑步记录App的源码分析和实现流程,其他类型的App也都有各自的特点和功能,开发者可以根据自己的需求进行开发并发布。

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