Question

我是android新手。我有一个主要的活动，我需要调用不同的类来执行不同的功能。但是每当我同时调用两个类时，只调用最后一个意图。有人可以建议在活动中同时调用2个或更多课程的方法。谢谢

以下是我的代码示例

主要活动

public class locationInfo extends AppCompatActivity {

    public Api mApi;
    public TextView coordinates;
    public String currentLocation = "";
    public String longitude;
    public String latitude;
    public Button data;
    public String altitude, speed;

    public int speedLimit;

    //calling gps class from sygic lib
    GpsPosition gpsPos = new GpsPosition();

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

        coordinates = (TextView) findViewById(R.id.textView);




        // sygicGetData();
        try {
            Log.v("debug", "Location is...1" );
            boolean satInfo = true;
            int maxTime = 0;

            gpsPos = ApiNavigation.getActualGpsPosition(satInfo, maxTime);
            longitude = String.valueOf(gpsPos.getLongitude());
            latitude = String.valueOf(gpsPos.getLatitude());
            altitude = String.valueOf(gpsPos.getAltitude());
            speed = String.valueOf(gpsPos.getSpeed());
            speedLimit = ApiInfo.getCurrentSpeedLimit(maxTime);
            Log.v("debug", "Location is...2" );
            Position pos = new Position();
            pos.setPosition(gpsPos.getLongitude(), gpsPos.getLatitude());
            currentLocation = ApiLocation.getLocationAddressInfo(pos, maxTime);


            coordinates.setText("\n" + "Current Location:" + currentLocation + "\n" + "Longitude:" + longitude + "\n" + "Latitude:" + latitude +
                    "\n" + "Altitude:" + altitude + "\n" + "Current Speed:" + speed +
                    "\n" + "Speed Limit:" + speedLimit);

        } catch (GpsException e) {
            Log.e("GpsPosition", "Error code:" + e.getCode());
        } catch (InvalidLocationException e) {
            Log.e("Location", "Error code:" + e.getCode());
        } catch (GeneralException e) {
            e.printStackTrace();
        }
    }
}

locationInfo类

public class routeInfo extends AppCompatActivity  {

    public String remainingDistance, remainingTime;
    public String totalDistance, totalTime;
    public Button data;
    public TextView coordinates;
    public RouteInfo routeInfo;


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

        coordinates = (TextView)findViewById(R.id.textView2);


        // sygicGetData();
        try {
            boolean info = true;
            int maxTime = 0;

            routeInfo = ApiNavigation.getRouteInfo(info, maxTime);
            totalDistance = String.valueOf(routeInfo.getTotalDistance());
            remainingDistance = String.valueOf(routeInfo.getRemainingDistance());
            totalTime = String.valueOf(routeInfo.getTotalTime());
            remainingTime = String.valueOf(routeInfo.getRemainingTime());

            coordinates.setText("\n" + "Total Travel Distance:" + totalDistance + "\n" + "Remaining Travel Distance:" + remainingDistance + "\n" + "Total Travel Time:" + totalTime + "\n" +
                    "Remaining Travel Time:" + remainingTime + "\n");

        } catch (GpsException e) {
            Log.e("GpsPosition", "Error code:" + e.getCode());
        } catch (InvalidLocationException e) {
            Log.e("Location", "Error code:" + e.getCode());
        } catch (GeneralException e) {
            e.printStackTrace();
        }
    }
}

routeInfo类

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.jackfruit.sygicdata4">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".getters.locationInfo"></activity>
        <activity android:name=".getters.routeInfo"></activity>
    </application>

</manifest>

Android清单

{{1}}

Answer 1

确定，

startActivities()

用于构造称为合成后向堆栈的东西。

在应用程序中，当您从1个活动移动到另一个活动而不调用

时

finish()

在您构建称为“backstack”的任何活动中。它被称为后台堆栈，因为当您持续按下后退按钮时，它是一堆活动。

如果你想人为地制作一个后座，你会

-startActivities()

这样做是人为地将最后一个意图的活动插入到后台堆栈中。

如果您想运行activit 1然后运行activity2 只需致电

startActivity()

单独

如果你想让2个任务并行运行，你需要使用一个名为“AsyncTask”的东西。文献here

Android从主要活动中调用2个或更多类

1 个答案: