问题
I have this problem accessing an extra from an intent.
The value i'm parsing is a long type, and I need this value to be stored in a database.
So this is what I have so far:
MainActivity:
package com.example.calendar;
import java.sql.Date;
import java.util.Calendar;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.CalendarView;
import static android.provider.BaseColumns._ID;
import static com.example.calendar.Constants.TABLE_NAME;
import static com.example.calendar.Constants.TIME;
import static com.example.calendar.Constants.TITLE;
import static com.example.calendar.Constants.DETAILS;
import static com.example.calendar.Constants.DATE;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
public class MainActivity extends Activity implements OnClickListener {
private AppointmentsData appointments;
CalendarView calendar;
Date date = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
View createButton = findViewById(R.id.btn_create);
View editButton = findViewById(R.id.btn_viewEdit);
View deleteButton = findViewById(R.id.btn_delete);
View moveButton = findViewById(R.id.btn_move);
View searchButton = findViewById(R.id.btn_search);
View translateButton = findViewById(R.id.btn_translate);
View exitButton = findViewById(R.id.exit);
createButton.setOnClickListener(this);
editButton.setOnClickListener(this);
deleteButton.setOnClickListener(this);
moveButton.setOnClickListener(this);
searchButton.setOnClickListener(this);
translateButton.setOnClickListener(this);
exitButton.setOnClickListener(this);
appointments = new AppointmentsData(this);
calendar.setOnDateChangeListener(new CalendarView.OnDateChangeListener() {
public void onSelectedDayChange(CalendarView view, int year, int month, int dayOfMonth) {
date = new Date(year, month, dayOfMonth);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i;
switch (v.getId()) {
case R.id.btn_create:
i = new Intent(this, CreateAppointment.class);
i.putExtra(DATE, date.getTime());
startActivity(i);
break;
case R.id.btn_viewEdit:
i = new Intent(this, EditViewAppointment.class);
i.putExtra(DATE, date.getTime());
startActivity(i);
break;
case R.id.btn_move:
i = new Intent(this, MoveAppointment.class);
i.putExtra(DATE, date.getTime());
startActivity(i);
break;
case R.id.btn_delete:
i = new Intent(this, DeleteAppointment.class);
i.putExtra(DATE, date.getTime());
startActivity(i);
break;
case R.id.btn_search:
i = new Intent(this, SearchAppointment.class);
startActivity(i);
break;
case R.id.btn_translate:
i = new Intent(this, TranslateAppointment.class);
i.putExtra(DATE, date.getTime());
startActivity(i);
break;
case R.id.exit:
finish();
break;
}
}
}
And the other Activity to use the value:
package com.example.calendar;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CalendarView;
import android.widget.EditText;
import android.app.Activity;
import android.content.Intent;
import static android.provider.BaseColumns._ID;
import static com.example.calendar.Constants.TABLE_NAME;
import static com.example.calendar.Constants.TIME;
import static com.example.calendar.Constants.TITLE;
import static com.example.calendar.Constants.DETAILS;
import static com.example.calendar.Constants.DATE;
import static com.example.calendar.Constants.CONTENT_URI;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
public class CreateAppointment extends Activity implements OnClickListener{
private static String[] FROM = { _ID, DATE, TIME, TITLE, DETAILS};
private static String ORDER_BY = TIME + " ASC";
AppointmentsData appointments;
CalendarView calendar;
String string;
EditText nameTextBox;
EditText timeTextBox;
EditText detailsTextBox;
Button createButton;
SQLiteDatabase db;
Intent fetchDate = getIntent();
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.create);
createButton = (Button) findViewById(R.id.apptSave);
nameTextBox = (EditText)findViewById(R.id.apptName);//Assign the global name box
timeTextBox = (EditText)findViewById(R.id.apptTime);//Assign the global time box
detailsTextBox = (EditText)findViewById(R.id.apptDetails);//Assign the global details box
calendar = (CalendarView)findViewById(R.id.calendar);
createButton.setOnClickListener(this);
appointments = new AppointmentsData(this);
string = "row";
long dateFecth = fetchDate.getLongExtra(DATE, defaultValue);
}
private void addAppointment(String string) {
/* Insert a new record into the Events data
source. You would do something similar
for delete and update. */
String getTitle = nameTextBox.getText().toString();
String getTime = timeTextBox.getText().toString();
String getDetails = detailsTextBox.getText().toString();
db = appointments.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(DATE, calendar.getDate());
values.put(TIME, getTime);
values.put(TITLE, getTitle);
values.put(DETAILS, getDetails);
getContentResolver().insert(CONTENT_URI, values);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch(v.getId()){
case R.id.apptSave:
addAppointment(string);
finish();
break;
}
}
}
The error is on the long dateFecth = fetchDate.getLongExtra(DATE, defaultValue); line and I don't know what to use for the second argument, since everything I think of gives me an error.
Can someone please help me with this?
回答1:
Move fetchDate = getIntent(); inside onCreate method of Activity as:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.create);
//.your code here..
fetchDate = getIntent(); // get intent here from previous Activity
long dateFecth = fetchDate.getLongExtra(DATE, defaultValue);
}
回答2:
First check - Value is associated with the given name. if you don't want to use defaultValue try with bundle as follow
if (getchDate.hasExtra("Date")) {
Bundle bundle = new Bundle();
bundle = getchDate.getExtras();
Object object = bunlde.get(Date);
Now parse this object in your desire type.
}
回答3:
You should check if result of getIntent() is not empty at first (an of course the call should be inside onCreate, not constructor). If it's not empty, then get long variable from it. defaultValue stands for a value returned from a method if a value for specified key is not found.
来源：https://stackoverflow.com/questions/22485072/how-do-i-get-extra-from-an-intent-as-a-type-long