当我在另一个活动中时如何完成活动

Question

当我将共享首选项类用作单独的类时，我将检查用户是否已登录导航活动类，如果是第一次，则将我转移到登录活动中，否则继续导航活动

但我的问题是，当我要返回登录活动时，它应该关闭应用程序，但它会将我转移到导航活动中......请帮助我......

package com.apkglobal.no_dues;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;

public class Shared {
    SharedPreferences sp;
    SharedPreferences.Editor ed;
    String Filename="himanshu";
    int mode=0;
    Context context;
    String First="first";


public Shared(Context context) {
    this.context = context;
   sp=context.getSharedPreferences(Filename,mode);
    ed=sp.edit();
}


public void secondtime()
{
    ed.putBoolean(First,true);
    ed.commit();
}

public boolean firsttime()
{
    if(!this.isfirst())
    {
        Intent i=new Intent(context,LoginActivity.class);
        i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(i);

    }
    return false;
}

public boolean isfirst() {
    return sp.getBoolean(First,false);
}

public void getback()
{
    ed.putBoolean(First,false);
    ed.commit();
}


}

Navigationacitivity.class

package com.apkglobal.no_dues;

import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AlertDialog;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.TextView;

import com.apkglobal.no_dues.Fragment.AboutFragment;
import com.apkglobal.no_dues.Fragment.BookDetailsFragment;
import com.apkglobal.no_dues.Fragment.FeedbackFragment;
import com.apkglobal.no_dues.Fragment.HomeFragment;
import com.apkglobal.no_dues.Fragment.MarksFragment;
import com.apkglobal.no_dues.Fragment.NoDuesFormFragment;

public class NavigationActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener{
    Button btn_mis,btn_attendence;
    Shared shared;
    String rollno;
    SharedPreferences sp;
    SharedPreferences.Editor ed;

    NavigationView navigationView;

    TextView tv_rollno;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        shared = new Shared(getApplicationContext());
        shared.firsttime();

        setContentView(R.layout.activity_navigation);

        btn_attendence = (Button) findViewById(R.id.btn_attendence);
        btn_mis=(Button)findViewById(R.id.btn_mis);
        tv_rollno = (TextView)findViewById(R.id.tv_rollno);

        navigationView = (NavigationView) findViewById(R.id.nav_view);

        View header=navigationView.getHeaderView(0);

        tv_rollno = (TextView)header.findViewById(R.id.tv_rollno);



        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);





       sp=getSharedPreferences("rajput",MODE_PRIVATE);
         rollno=sp.getString("rollno",null);


         tv_rollno.setText(rollno);





        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();

              navigationView.setNavigationItemSelectedListener(this);




        defaultSelectitem(R.id.nav_homepage);



    }






    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);

        }

         else {


            AlertDialog.Builder ab = new AlertDialog.Builder(NavigationActivity.this);
            ab.setIcon(R.drawable.logo);
            ab.setTitle("Exit Application");
            ab.setMessage("Are You Sure ?");
            ab.setCancelable(false);
            ab.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    finish();
                }
            });
            ab.setNegativeButton("No", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.dismiss();
                }
            });
            ab.create();
            ab.show();
        }


    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.navigation, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            Intent i = new Intent(getApplicationContext(), SettingActivity.class);
            startActivity(i);
        } else if (id == R.id.action_contact) {
            Intent i = new Intent(getApplicationContext(), ContactActivity.class);
            startActivity(i);
        } else if (id == R.id.action_search) {

        }

        return super.onOptionsItemSelected(item);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        defaultSelectitem(item.getItemId());


        return true;
    }


    private void defaultSelectitem(int itemId) {

        Fragment fragment = null;

        switch (itemId) {
            case R.id.nav_homepage:
                fragment = new HomeFragment();
                break;

            case R.id.nav_nodues_form:
                fragment = new NoDuesFormFragment();
                break;

            case R.id.nav_feedback:
                fragment = new FeedbackFragment();
                break;

            case R.id.nav_marks:
                fragment = new MarksFragment();
                break;

            case R.id.nav_book:
                fragment = new BookDetailsFragment();
                break;

            case R.id.nav_about:
                fragment = new AboutFragment();
                break;

            case R.id.nav_fees_detail:

                            Intent intent = new Intent(NavigationActivity.this,FeesDetail.class);
             startActivity(intent);


                break;

            case R.id.nav_share:

                break;

            case R.id.nav_logout:
                shared.getback();
                Intent i = new Intent(getApplicationContext(), LoginActivity.class);
                startActivity(i);

                finish();

                break;
        }

        if (fragment != null) {
            FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction().replace(R.id.frame, fragment);
            fragmentTransaction.commit();

        }
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);

    }


}

Answer 1

您必须将 Activity 作为参数而不是上下文。然后在开始活动后，您应该完成当前活动。

你的代码应该是这样的。

package com.apkglobal.no_dues;

import android.content.Intent;
import android.content.SharedPreferences;

public class Shared {
    SharedPreferences sp;
    SharedPreferences.Editor ed;
    String Filename="himanshu";
    int mode=0;
    Activity activity;
    String First="first";


public Shared(Activity activity) {
    this.activity= context;
   sp=activity.getSharedPreferences(Filename,mode);
    ed=sp.edit();
}


public void secondtime()
{
    ed.putBoolean(First,true);
    ed.commit();
}

public boolean firsttime()
{
    if(!this.isfirst())
    {
        Intent i=new Intent(activity,LoginActivity.class);
        i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        activity.startActivity(i);
        activity.finish();

    }
    return false;
}

public boolean isfirst() {
    return sp.getBoolean(First,false);
}

public void getback()
{
    ed.putBoolean(First,false);
    ed.commit();
}


}

希望对你有帮助:)

Answer 2

在您的Manifest.xml 中添加android:noHistory=true 以获得LoginActivity。这样Login Activity就不会在后台了。

Answer 3

只需添加finish() 即可完成当前活动：

if(!this.isfirst()){
    Intent i=new Intent(context,LoginActivity.class);
    i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
    i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    context.startActivity(i);
    finish()
}

Answer 4

use NavigationActivity.this instead of getApplicationContext()

shared = new Shared(NavigationActivity.this);
shared.firsttime();

and call finish(); method after startActivity();