Question

我制作了纬度和经度全局变量。

它在MyLocationListener类中工作正常，因为它显示当前位置的纬度和经度，但是当它在webview中加载url（http://maps.google.com/maps?" + "saddr=" + currentLattitude + "," + currentLongtitude + "&daddr=27.11,85.11")）时，它会加载值0和0。

为什么？

public class ShowMapActivity extends Activity {

private WebView webView;
double currentLattitude;
double currentLongtitude;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.webview);

    LocationManager mlocManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    LocationListener mlocListener = new MyLocationListener();
    mlocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0,
            mlocListener);

    webView = (WebView) findViewById(R.id.webView1);
    webView.getSettings().setJavaScriptEnabled(true);
    webView.setWebViewClient(new WebViewClient());
    webView.loadUrl("http://maps.google.com/maps?" + "saddr="
            + currentLattitude + "," + currentLongtitude
            + "&daddr=27.11,85.11");

}

public class MyLocationListener implements LocationListener
{
    @Override
    public void onLocationChanged(Location loc)
    {
        currentLattitude = loc.getLatitude();

        currentLongtitude = loc.getLongitude();

        Toast.makeText(
                getApplicationContext(),

                "Latitude is: " + currentLattitude + " Longitude is: "
                        + currentLongtitude,

                Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onProviderDisabled(String provider)
    {

        Toast.makeText(getApplicationContext(),

        "Gps Disabled",

        Toast.LENGTH_SHORT).show();

    }

    @Override
    public void onProviderEnabled(String provider)
    {

        Toast.makeText(getApplicationContext(), "Gps Enabled",

        Toast.LENGTH_SHORT).show();

    }

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

    }
}
}

Answer 1

尝试将这段代码放在onLocationChanged

中

webView = (WebView) findViewById(R.id.webView1); 
webView.getSettings().setJavaScriptEnabled(true); 
webView.setWebViewClient(new WebViewClient()); 
webView.loadUrl("http://maps.google.com/maps?" + "saddr=" 
        + currentLattitude + "," + currentLongtitude 
        + "&daddr=27.11,85.11");

Answer 2

在onLocationChanged(...)

中添加此内容

 webView.loadUrl("http://maps.google.com/maps?" + "saddr="
            + currentLattitude + "," + currentLongtitude
            + "&daddr=27.11,85.11");

Answer 3

你的双变量给出了下面一行的默认值。因为在更新下面的位置之前正在执行

webView.loadUrl("http://maps.google.com/maps?" + "saddr="
            + currentLattitude + "," + currentLongtitude
            + "&daddr=27.11,85.11");

Answer 4

因为您在onCreate()函数中打开了WebView，并且您在onLocationChanged()函数中获得了位置。为了解决这个问题，如果你想要总是在更改位置时更新Web视图，只需将它放在函数onLocationChanged()中，如果你想在它可以使用布尔变量时加载它onLocationChanged()表示这是您第一次使用此功能。

提高效率：您最好在获得位置后删除更新以避免电池耗尽。

如何制作纬度和经度全局变量？

4 个答案: