Android：导航抽屉中的TextView不包含登录活动中的用户名

时间：2018-09-15 14:05:04

标签： android

正如标题所述，我的应用程序已连接到MySQL数据库。因此，该应用程序从数据库中获取用户名。我希望用户名显示在导航标题上。但是失败了。我尝试在空的活动中使用它，但成功了。

使用导航抽屉的示例：

Example of using Navigation Drawer

使用空活动的示例：

Example of using empty activity

H_Admin.java（导航抽屉）

package com.example.asusn46jv.sharepreference;

import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
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.TextView;

public class H_Admin extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_h__admin);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);


    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });

    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.addDrawerListener(toggle);
    toggle.syncState();

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



}

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

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

    return super.onOptionsItemSelected(item);
}

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

    if (id == R.id.nav_camera) {
        // Handle the camera action
    } else if (id == R.id.nav_gallery) {

    } else if (id == R.id.nav_slideshow) {

    } else if (id == R.id.nav_manage) {

    } else if (id == R.id.nav_share) {

    } else if (id == R.id.nav_send) {

    }

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

这是MainActivity.java（起作用的那个）

package com.example.asusn46jv.sharepreference;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView; 

public class MainActivity extends AppCompatActivity {

Button btn_logout;
TextView txt_id, txt_username;
String id, username;
SharedPreferences sharedpreferences;

public static final String TAG_ID = "id";
public static final String TAG_USERNAME = "username";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    txt_id = (TextView) findViewById(R.id.txt_id);
    txt_username = (TextView) findViewById(R.id.txt_username);
    btn_logout = (Button) findViewById(R.id.btn_logout);

    sharedpreferences = getSharedPreferences(Login.my_shared_preferences, Context.MODE_PRIVATE);

    id = getIntent().getStringExtra(TAG_ID);
    username = getIntent().getStringExtra(TAG_USERNAME);

    txt_id.setText("ID : " + id);
    txt_username.setText("USERNAME : " + username);

    btn_logout.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            // update login session ke FALSE dan mengosongkan nilai id dan username
            SharedPreferences.Editor editor = sharedpreferences.edit();
            editor.putBoolean(Login.session_status, false);
            editor.putString(TAG_ID, null);
            editor.putString(TAG_USERNAME, null);
            editor.commit();

            Intent intent = new Intent(MainActivity.this, Login.class);
            finish();
            startActivity(intent);
        }
    });
}
}

Login.java 

package com.example.asusn46jv.sharepreference;

import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.ConnectivityManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.example.asusn46jv.sharepreference.app.AppController;

import org.json.JSONException;
import org.json.JSONObject;

import java.util.HashMap;
import java.util.Map;

public class Login extends AppCompatActivity {


ProgressDialog pDialog;
Button btn_register, btn_login;
EditText txt_username, txt_password;
Intent intent;

int success;
ConnectivityManager conMgr;

private String url = Server.URL + "login1.php";

private static final String TAG = Login.class.getSimpleName();

private static final String TAG_SUCCESS = "success";
private static final String TAG_MESSAGE = "message";

public final static String TAG_USERNAME = "username";
public final static String TAG_ID = "id";

String tag_json_obj = "json_obj_req";

SharedPreferences sharedpreferences;
Boolean session = false;
String id, username;
public static final String my_shared_preferences = "my_shared_preferences";
public static final String session_status = "session_status";


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_login);

    conMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    {
        if (conMgr.getActiveNetworkInfo() != null
                && conMgr.getActiveNetworkInfo().isAvailable()
                && conMgr.getActiveNetworkInfo().isConnected()) {
        } else {
            Toast.makeText(getApplicationContext(), "No Internet Connection",
                    Toast.LENGTH_LONG).show();
        }
    }

    btn_login = (Button) findViewById(R.id.btn_login);
    btn_register = (Button) findViewById(R.id.btn_register);
    txt_username = (EditText) findViewById(R.id.txt_username);
    txt_password = (EditText) findViewById(R.id.txt_password);

    // Cek session login jika TRUE maka langsung buka MainActivity
    sharedpreferences = getSharedPreferences(my_shared_preferences, Context.MODE_PRIVATE);
    session = sharedpreferences.getBoolean(session_status, false);
    id = sharedpreferences.getString(TAG_ID, null);
    username = sharedpreferences.getString(TAG_USERNAME, null);

    if (session) {
        Intent intent = new Intent(Login.this, MainActivity.class);
        intent.putExtra(TAG_ID, id);
        intent.putExtra(TAG_USERNAME, username);
        finish();
        startActivity(intent);
    }


    btn_login.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            String username = txt_username.getText().toString();
            String password = txt_password.getText().toString();

            // mengecek kolom yang kosong
            if (username.trim().length() > 0 && password.trim().length() > 0) {
                if (conMgr.getActiveNetworkInfo() != null
                        && conMgr.getActiveNetworkInfo().isAvailable()
                        && conMgr.getActiveNetworkInfo().isConnected()) {
                    checkLogin(username, password);
                } else {
                    Toast.makeText(getApplicationContext() ,"No Internet Connection", Toast.LENGTH_LONG).show();
                }
            } else {
                // Prompt user to enter credentials
                Toast.makeText(getApplicationContext() ,"Kolom tidak boleh kosong", Toast.LENGTH_LONG).show();
            }
        }
    });

    btn_register.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            intent = new Intent(Login.this, Register.class);
            finish();
            startActivity(intent);
        }
    });

}

private void checkLogin(final String username, final String password) {
    pDialog = new ProgressDialog(this);
    pDialog.setCancelable(false);
    pDialog.setMessage("Logging in ...");
    showDialog();

    StringRequest strReq = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {

        @Override
        public void onResponse(String response) {
            Log.e(TAG, "Login Response: " + response.toString());
            hideDialog();

            try {
                JSONObject jObj = new JSONObject(response);
                success = jObj.getInt(TAG_SUCCESS);

                // Check for error node in json
                if (success == 1) {
                    String username = jObj.getString(TAG_USERNAME);
                    String id = jObj.getString(TAG_ID);

                    Log.e("Successfully Login!", jObj.toString());

                    Toast.makeText(getApplicationContext(), jObj.getString(TAG_MESSAGE), Toast.LENGTH_LONG).show();

                    // menyimpan login ke session
                    SharedPreferences.Editor editor = sharedpreferences.edit();
                    editor.putBoolean(session_status, true);
                    editor.putString(TAG_ID, id);
                    editor.putString(TAG_USERNAME, username);
                    editor.commit();

                    // Memanggil main activity
                    Intent intent = new Intent(Login.this, MainActivity.class);
                    intent.putExtra(TAG_ID, id);
                    intent.putExtra(TAG_USERNAME, username);
                    finish();
                    startActivity(intent);

                } else {
                    Toast.makeText(getApplicationContext(),
                            jObj.getString(TAG_MESSAGE), Toast.LENGTH_LONG).show();

                }
            } catch (JSONException e) {
                // JSON error
                e.printStackTrace();
            }

        }
    }, new Response.ErrorListener() {

        @Override
        public void onErrorResponse(VolleyError error) {
            Log.e(TAG, "Login Error: " + error.getMessage());
            Toast.makeText(getApplicationContext(),
                    error.getMessage(), Toast.LENGTH_LONG).show();

            hideDialog();

        }
    }) {

        @Override
        protected Map<String, String> getParams() {
            // Posting parameters to login url
            Map<String, String> params = new HashMap<String, String>();
            params.put("username", username);
            params.put("password", password);

            return params;
        }

    };

    // Adding request to request queue
    AppController.getInstance().addToRequestQueue(strReq, tag_json_obj);
}

private void showDialog() {
    if (!pDialog.isShowing())
        pDialog.show();
}

private void hideDialog() {
    if (pDialog.isShowing())
        pDialog.dismiss();
}

}

1 个答案:

答案 0 :(得分：0)

您的导航抽屉不是MainActivity的一部分。因此，您应该首先获取它的实例。尝试这样做：

// get Navigation view
navigationView = (NavigationView) findViewById(R.id.nav_view);

// get header
        navHeader = navigationView.getHeaderView(0);

// then set your names
navHeader.txt_username.setText("USERNAME : " + username);
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