接收GPS訊號

這個範例是讀取android程式執行時所在的GPS座標,並將之顯示於畫面上。
GPSsample.JPG
圖2-1
以下為接收GPS訊號的程式碼:
專案下載:GPSsample.rar
程式:GPSsample.java

package GPSsample.a;
 
import android.app.Activity;
import android.os.Bundle;
import android.widget.EditText;
import android.widget.TextView;
 
// 引用GPS
import android.location.*;
 
public class GPSsample extends Activity {
    /** Called when the activity is first created. */
    // GPS初始化
    private LocationManager localManager;
    private LocationListener locationListener;
 
    // 文字方塊初始化
    private EditText lngText;
    private EditText latText;
 
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
 
        // 初始化GPS服務
        localManager = (LocationManager) getSystemService(GPSsample.this.LOCATION_SERVICE);
 
        // 初始化事件
        locationListener = new MyLocationListener();
 
        // 事件更新
        localManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0,
                locationListener);  
 
        // 初始化顯示文字
        final TextView lngView = (TextView) findViewById(R.id.lngTextView);
        final TextView latView = (TextView) findViewById(R.id.latTextView);
 
        lngView.setText("經度:");
        latView.setText("緯度:");
 
        // 初始化文字方塊
        lngText = (EditText) findViewById(R.id.lngEditText);
        latText = (EditText) findViewById(R.id.latEditText);
        lngText.setText("118.32198666666666");
        latText.setText("24.449396666666669");
    }
 
    private class MyLocationListener implements LocationListener 
    {
        // GPS位置事件更新
        public void onLocationChanged(Location loc) {
            if (loc != null){
                lngText.setText(Double.toString(loc.getLongitude()));
                latText.setText(Double.toString(loc.getLatitude()));
            }
        }
 
        public void onProviderDisabled(String provider) {
            // TODO Auto-generated method stub
        }
 
        public void onProviderEnabled(String provider) {
            // TODO Auto-generated method stub
        }
 
        public void onStatusChanged(String provider, int status, 
            Bundle extras) {
            // TODO Auto-generated method stub
        }
    }
}

Activity介面程式碼

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout
android:id="@+id/widget0"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
>
<TextView
android:id="@+id/lngTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView"
android:layout_x="4px"
android:layout_y="19px"
>
</TextView>
<TextView
android:id="@+id/latTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView"
android:layout_x="5px"
android:layout_y="81px"
>
</TextView>
<EditText
android:id="@+id/lngEditText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="EditText"
android:textSize="18sp"
android:layout_x="69px"
android:layout_y="67px"
>
</EditText>
<EditText
android:id="@+id/latEditText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="EditText"
android:textSize="18sp"
android:layout_x="68px"
android:layout_y="11px"
>
</EditText>
</AbsoluteLayout>

AndroidManifest.xml為使用權限:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="GPSsample.a"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".GPSsample"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
 
    </application>
    <uses-sdk android:minSdkVersion="4" />
    <!-- GPS權限設定 -->
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
</manifest>

程式影片解說