您好我想对以下代码进行解释。在这里有时我的javascript功能正在运行，有时它不是。结果，我真的不知道问题出在哪里。这里我的index.html文件自动加载地图位置。然后我用当前的lat，lng作为参数调用javascript函数。所以，最初它会加载默认地图。然后应该通过javascript函数覆盖地图。问题有时会发生，有时则不然。所以，我想对此有一个答案。
public class MapOptionsDemoModified extends Activity{
//Geocoder geocoder;
WebView mWebView;
LocationManager mlocManager=null;
LocationListener mlocListener;
private MyLocationOverlay myLocationOverlay;
protected MapView map;
private RadioButton mapButton;
private RadioButton satelliteButton;
private ToggleButton trafficToggle;
private ToggleButton labelsToggle;
private Configuration config;
EditText LOC;
Button routesbtn,settingsbtn;
public String location="State Street"
double lati,longi;
GeoPoint currentLocation;
double curlat,curlong;
InputMethodManager imm;
//String adrs;
double latitude=40.07546;
double longitude=-76.329999;
String adrs="";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map_options_modified);
lati=34.1161;
longi=-118.149399;
adrs="";
routesbtn=(Button)findViewById(R.id.mom_bt2);
mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
mlocManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
mWebView = (WebView) findViewById(R.id.webview);
WebSettings webSettings = mWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
mWebView.loadUrl("file:///android_asset/index.html");
//mWebView.loadUrl("http://www.google.com");
webSettings.setBuiltInZoomControls(true);
webSettings.setSupportZoom(true);
imm=(InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
/* taking data from caller activity page */
// ###################Receiving data starts
Bundle extras = getIntent().getExtras();
if (extras == null) {
return;
}
lati=extras.getDouble("latitude");
longi = extras.getDouble("longitude");
adrs=extras.getString("adrs");
// ##### Receiving data ends
AlertDialog.Builder pdb=new AlertDialog.Builder(MapOptionsDemoModified.this);
pdb.setTitle("GPS");
pdb.setMessage(adrs+" "+Double.toString(lati)+" "+Double.toString(longi));
pdb.setPositiveButton("Ok", null);
pdb.show();
mWebView.loadUrl("javascript:getCurrentLocation("+lati+","+longi+")");
routesbtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(mlocManager.isProviderEnabled(LocationManager.GPS_PROVIDER)){
//while(j<cnt)
//{
mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
if(MyLocationListener.latitude>0)
{
latitude=MyLocationListener.latitude;
longitude=MyLocationListener.longitude;
//flag=1;
Geocoder gcd = new Geocoder(MapOptionsDemoModified.this, Locale.getDefault());
List<Address> addresses;
try {
addresses = gcd.getFromLocation(latitude,longitude, 5);
if (addresses.size() > 0)
{
adrs=addresses.get(0).getAddressLine(0)+" "+addresses.get(0).getAddressLine(1)+" "+addresses.get(0).getAddressLine(2);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//break;
finish();
Intent i = new Intent(MapOptionsDemoModified.this,RoutesPageOne.class);
i.putExtra("adrs", adrs);
i.putExtra("latitude", latitude);
i.putExtra("longitude", longitude);
startActivity(i);
}
else
{
AlertDialog.Builder pdb=new AlertDialog.Builder(MapOptionsDemoModified.this);
pdb.setTitle("GPS");
pdb.setMessage("GPS activation in progress");
pdb.setPositiveButton("Ok", null);
pdb.show();
}
//}
}
else {
AlertDialog.Builder pdb=new AlertDialog.Builder(MapOptionsDemoModified.this);
pdb.setTitle("GPS");
pdb.setMessage("GPS is not turned on..., please start gps");
pdb.setPositiveButton("Ok", null);
pdb.show();
}
}
});
LOC=(EditText)findViewById(R.id.mom_editText1);
LOC.setOnKeyListener(new OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
// TODO Auto-generated method stub
location = LOC.getText().toString();
if (keyCode == KeyEvent.KEYCODE_ENTER && location.length() > 0) {
LOC.setText("");
imm.hideSoftInputFromWindow(LOC.getWindowToken(), 0);
mWebView.loadUrl("javascript:getLocation('" + location + "')");
/*AlertDialog.Builder edb=new AlertDialog.Builder(MapOptionsDemoModified.this);
edb.setTitle("gps");
edb.setMessage(location+" lat= "+lati+" long="+longi);
edb.setPositiveButton("Ok", null);
edb.show();*/
//searchBarcode(barcode);
return true;
}
return false;
}
});
//imm.hideSoftInputFromWindow(myEditText.getWindowToken(), 0);
getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
mWebView.setWebViewClient(new HelloWebViewClient());
private class HelloWebViewClient extends WebViewClient {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
}
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK) && mWebView.canGoBack()) {
mWebView.goBack();
return true;
}
return super.onKeyDown(keyCode, event);
}
}
答案 0 :(得分：0)
问题出在时间上。有时，第一个url需要花费更多时间来加载，因此第二个url没有被调用。所以我在loadUrl调用之间包含了SystemClock.sleep(1000)，它就像魅力一样。