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私はあるページから別のページにデータを転送しようとしていますが、いくつかの問題がコードにあります。最初のアクティビティから2番目にバンドルを使って変数の値を転送しようとしていますが、何かが間違っていることを教えてください。1つのアクティビティで取られた入力を別のアクティビティに転送するにはどうすればよいですか？
以下は最初のアクティビティである： - アプリケーションが力を閉じているボタンを押すことで
public class MapRouteActivity extends MapActivity {
LinearLayout linearLayout;
MapView mapView;
private Road mRoad;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.routeplanning);
mapView = (MapView) findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
Bundle extras = this.getIntent().getExtras();
String fLat=extras.getString("fromLat");
String fLong=extras.getString("fromLong");
String tLat=extras.getString("toLat");
String tLong=extras.getString("toLong");
final double fromLat=Double.parseDouble(fLat);
final double fromLon=Double.parseDouble(fLong);
final double toLat=Double.parseDouble(tLat);
final double toLon=Double.parseDouble(tLong);
new Thread() {
@Override
public void run() {
//double fromLat = 28.6353, fromLon = 77.2250, toLat = 30.7313, toLon = 76.7754;
/***url contains the path to fetch the kml file from the internet*/
String url = RoadProvider
.getUrl(fromLat, fromLon, toLat, toLon);
InputStream is = getConnection(url);
mRoad = RoadProvider.getRoute(is);
mHandler.sendEmptyMessage(0);
}
}.start();
}
Handler mHandler = new Handler() {
public void handleMessage(android.os.Message msg) {
TextView textView = (TextView) findViewById(R.id.description);
textView.setText(mRoad.mName + " " + mRoad.mDescription);
MapOverlay mapOverlay = new MapOverlay(mRoad, mapView);
List<Overlay> listOfOverlays = mapView.getOverlays();
listOfOverlays.clear();
listOfOverlays.add(mapOverlay);
mapView.invalidate();
};
};
private InputStream getConnection(String url) {
InputStream is = null;
try {
//Opens a connection to the remote database(bidirectional)
URLConnection conn = new URL(url).openConnection();
is = conn.getInputStream();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return is;
}
@Override
protected boolean isRouteDisplayed() {
return false;
}
}
class MapOverlay extends com.google.android.maps.Overlay {
Road mRoad;
ArrayList<GeoPoint> mPoints;
public MapOverlay(Road road, MapView mv) {
mRoad = road;
if (road.mRoute.length > 0) {
mPoints = new ArrayList<GeoPoint>();
for (int i = 0; i < road.mRoute.length; i++) {
mPoints.add(new GeoPoint((int) (road.mRoute[i][1] * 1000000),
(int) (road.mRoute[i][0] * 1000000)));
}
int moveToLat = (mPoints.get(0).getLatitudeE6() + (mPoints.get(
mPoints.size() - 1).getLatitudeE6() - mPoints.get(0)
.getLatitudeE6())/2);
int moveToLong = (mPoints.get(0).getLongitudeE6() + (mPoints.get(
mPoints.size() - 1).getLongitudeE6() - mPoints.get(0)
.getLongitudeE6())/2);
GeoPoint moveTo = new GeoPoint(moveToLat, moveToLong);
MapController mapController = mv.getController();
mapController.animateTo(moveTo);
mapController.setZoom(9);
}
}
@Override
public boolean draw(Canvas canvas, MapView mv, boolean shadow, long when) {
super.draw(canvas, mv, shadow);
drawPath(mv, canvas);
return true;
}
public void drawPath(MapView mv, Canvas canvas) {
int x1 = -1, y1 = -1, x2 = -1, y2 = -1;
Paint paint = new Paint();
paint.setColor(Color.GREEN);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(3);
for (int i = 0; i < mPoints.size(); i++) {
Point point = new Point();
mv.getProjection().toPixels(mPoints.get(i), point);
x2 = point.x;
y2 = point.y;
if (i > 0) {
canvas.drawLine(x1, y1, x2, y2, paint);
}
x1 = x2;
y1 = y2;
}
}
}
- 以下
public class login extends Activity {
/** Called when the activity is first created. */
Context mCtx;
final static int START =0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mCtx = this;
Button btn = (Button)findViewById(R.id.btn);
btn.setOnClickListener(new OnClickListener(){
// @Override
public void onClick(View v)
{
String fromLat = new String();
String fromLong = new String();
String toLat = new String();
String toLong = new String();
fromLat = ((EditText)findViewById(R.id.FromLatitude)).getText().toString();
fromLong = ((EditText)findViewById(R.id.FromLongitude)).getText().toString();
toLat = ((EditText)findViewById(R.id.ToLatitude)).getText().toString();
toLong = ((EditText)findViewById(R.id.ToLongitude)).getText().toString();
Intent intent = new Intent(mCtx, MapRouteActivity.class);
/*Sending some arguments*/
Bundle bundle = new Bundle(4);
bundle.putString("fromLat",fromLat);
bundle.putString("fromLong",fromLong);
bundle.putString("toLat",toLat);
bundle.putString("toLong",toLong);
intent.putExtras(bundle);
/*Start Activity*/
mCtx.startActivity(intent);
/*Start ActivityForResult*/
((Activity)mCtx).startActivityForResult(intent, 2);
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);
if(requestCode == START)
{
Toast.makeText(mCtx, Integer.toString(resultCode), Toast.LENGTH_SHORT).show();
}
}
@Override
public void onDestroy(){
super.onDestroy();
finish();
}
}
第活動です。以下は
力のLogCatデータは、ラインlogin.javaの49に適用
02-02 15:32:31.837: ERROR/AndroidRuntime(199): Uncaught handler: thread main exiting due to uncaught exception
02-02 15:32:31.857: ERROR/AndroidRuntime(199): java.lang.NullPointerException
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at route.planning.login$1.onClick(login.java:49)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.view.View.performClick(View.java:2344)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.view.View.onTouchEvent(View.java:4133)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.widget.TextView.onTouchEvent(TextView.java:6504)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.view.View.dispatchTouchEvent(View.java:3672)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1712)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1202)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.app.Activity.dispatchTouchEvent(Activity.java:1987)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1696)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.view.ViewRoot.handleMessage(ViewRoot.java:1658)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.os.Handler.dispatchMessage(Handler.java:99)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.os.Looper.loop(Looper.java:123)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at android.app.ActivityThread.main(ActivityThread.java:4203)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at java.lang.reflect.Method.invokeNative(Native Method)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at java.lang.reflect.Method.invoke(Method.java:521)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
02-02 15:32:31.857: ERROR/AndroidRuntime(199): at dalvik.system.NativeStart.main(Native Method)
fromLat =（（のEditText）findViewById（R.id.FromLatitude））のgetText（）のtoString（）;これは行番号49 – Prachur
で、edittextが見つからず、nullが返されるか、その編集テキスト内のテキストが空です。ちょうどそれを見つけ出すためにデバッグしてください – WarrenFaith