不知道为什么 if 不起作用 android studio

Question

I'm trying to make a register page that unless all the edit texts contain something the user wont be able to continue, but i don't get why my if isn't working.

package com.example.nir.nestleapp;

import android.content.Intent;
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.TextView;
import android.widget.Toast;

import org.w3c.dom.Text;

import java.util.jar.Attributes;

public class RegisterActivity extends AppCompatActivity {
MyDBHandler db;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_register);
        TextView RegisterHead=(TextView)findViewById(R.id.RegisterHeadline);
        RegisterHead.setTextSize(25);
        Button CompleteRegister=(Button)findViewById(R.id.CompleteRegisterBtn);
        final EditText RegisteredUser=(EditText)findViewById(R.id.RegisteredUser);
        final EditText RegisteredPass=(EditText)findViewById(R.id.RegisteredPass);
        final EditText RegisteredName=(EditText)findViewById(R.id.RegisteredFn);
        final EditText RegisteredPhone=(EditText)findViewById(R.id.RegisteredPhone);
        final EditText RegisteredID=(EditText)findViewById(R.id.RegisteredID);
        final String User2String=String.valueOf(RegisteredUser.getText());
        final String Pass2String=String.valueOf(RegisteredPass.getText());
        final String Name2String=String.valueOf(RegisteredName.getText());
        final String Phone2String=String.valueOf(RegisteredPhone.getText());
        final String ID2String=String.valueOf(RegisteredID.getText());
        db=new MyDBHandler(this);
        CompleteRegister.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(User2String.equals("")||Pass2String.equals("")|| Name2String.equals("")||Phone2String.equals("")||ID2String.equals("")){
                    Toast.makeText(RegisterActivity.this, "", Toast.LENGTH_SHORT).show();
                }
                else {
                    UserTable NewUser=new UserTable(User2String,Pass2String,Name2String,Phone2String,ID2String);
                    db.Add(NewUser);
                    Toast.makeText(RegisterActivity.this, "", Toast.LENGTH_SHORT).show();
                    startActivity(new Intent(RegisterActivity.this, LoginActivity.class));
                }
            }
        });
    }
}

and another question, why does every time that i use Setonclicklistner method and i use some parameter that i declared outside the method it automatically change it to final

Answer 1

Your strings were declared in the onCreate method which means changes the user made were never taken into account in your onClick method. By moving your strings in the onClick method you should fix your problem.

So to fix your issue replace your code in onCreate with this:

    @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_register);
            TextView RegisterHead=(TextView)findViewById(R.id.RegisterHeadline);
            RegisterHead.setTextSize(25);
            Button CompleteRegister=(Button)findViewById(R.id.CompleteRegisterBtn);
            final EditText RegisteredUser=(EditText)findViewById(R.id.RegisteredUser);
            final EditText RegisteredPass=(EditText)findViewById(R.id.RegisteredPass);
            final EditText RegisteredName=(EditText)findViewById(R.id.RegisteredFn);
            final EditText RegisteredPhone=(EditText)findViewById(R.id.RegisteredPhone);
            final EditText RegisteredID=(EditText)findViewById(R.id.RegisteredID);

            CompleteRegister.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    final String User2String=String.valueOf(RegisteredUser.getText());
                    final String Pass2String=String.valueOf(RegisteredPass.getText());
                    final String Name2String=String.valueOf(RegisteredName.getText());
                    final String Phone2String=String.valueOf(RegisteredPhone.getText());
                    final String ID2String=String.valueOf(RegisteredID.getText());

                    db=new MyDBHandler(this);



                    if(User2String.equals("")||Pass2String.equals("")|| Name2String.equals("")||Phone2String.equals("")||ID2String.equals("")){
                        Toast.makeText(RegisterActivity.this, "", Toast.LENGTH_SHORT).show();
                    }
                    else {

                        UserTable NewUser=new UserTable(User2String,Pass2String,Name2String,Phone2String,ID2String);
                        db.Add(NewUser);
                        Toast.makeText(RegisterActivity.this, "", Toast.LENGTH_SHORT).show();
                        startActivity(new Intent(RegisterActivity.this, LoginActivity.class));
                    }
                }
            });
        }