无法连接到 Google FireBase

Question

我是安卓工作室的新手。在我的项目中，我创建了一个登录页面并在 google 上设置了 firebase 帐户并上传了一些数据（用户名、密码）。但我无法连接到火力基地。每次我运行它，应用程序都会在我的手机上闪回。任何人都可以帮助我这出了什么问题？

package com.example.edward.eventmanagementsystem;

import android.app.ProgressDialog;
import android.content.Intent;
import android.provider.ContactsContract;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.example.edward.eventmanagementsystem.model.Organizer;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

public class MainActivity extends AppCompatActivity {

    //private Button button;
    Button loginButton;
    EditText editLogin, editPass;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ActionBar actionBar = getSupportActionBar();
        actionBar.hide();

        editLogin = findViewById(R.id.editLogin);
        editPass = findViewById(R.id.editPass);

        loginButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent MainMenu =  new Intent(MainActivity.this, com.example.edward.eventmanagementsystem.MainMenu.class);
                startActivity(MainMenu);
            }
        });

        // Init Database
        FirebaseDatabase database = FirebaseDatabase.getInstance();
        final DatabaseReference table_user = database.getReference("Organizer");

        loginButton.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick (View view){

                final ProgressDialog mDialog = new ProgressDialog(MainActivity.this);
                mDialog.setMessage("Please waiting...");
                mDialog.show();

                table_user.addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(DataSnapshot dataSnapshot) {

                        //check if user does't exists in database
                        if(dataSnapshot.child(editLogin.getText().toString()).exists()) {
                            //get organizer sign in information
                            mDialog.dismiss();
                            Organizer organizer = dataSnapshot.child(editLogin.getText().toString()).getValue(Organizer.class);

                            if(organizer.getPassword().equals(editPass.getText().toString())){
                                Toast.makeText(MainActivity.this, "Sign in successfully!", Toast.LENGTH_SHORT).show();
                            }
                            else {
                                Toast.makeText(MainActivity.this, "Sign in failed!", Toast.LENGTH_SHORT).show();
                            }
                        }
                        else
                        {
                            Toast.makeText(MainActivity.this, "User not exists in database.", Toast.LENGTH_SHORT).show();
                        }
                    }
                    @Override
                    public void onCancelled(DatabaseError databaseError) {
                    }
                });
            }
        });
    }

/** Called when the user taps the Send button 
public void onClick(View view){
Intent intent = new Intent(this, MainMenu.class);
startActivity(intent);
}*/

}

Answer 1

登录Button有两个监听器，这甚至让我感到困惑：

loginButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent MainMenu =  new Intent(MainActivity.this, com.example.edward.eventmanagementsystem.MainMenu.class);
            startActivity(MainMenu);
        }
    });

loginButton.setOnClickListener(new View.OnClickListener(){

当您单击 Button 时，它将转到另一个名为 MainMenu 的 Activity 类但您还有另一个监听器，它负责 Firebase 的工作.

解决方案：

使用一个带有 firebase 代码的侦听器，当 firebase 登录成功后，转到另一个 Activity：

if(organizer.getPassword().equals(editPass.getText().toString())){
   Toast.makeText(MainActivity.this, "Sign in successfully!", Toast.LENGTH_SHORT).show();

  Intent MainMenu =  new Intent(MainActivity.this, MainMenu.class);
  startActivity(MainMenu);
  // Here use this code to go to another activity class

}