Question

Registration_Form.java

这是我的注册表格，我想通过SharedPreferences将用户名从注册移到登录，请帮助我告诉我编码错误的地方。

package com.example.android.demo;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.support.annotation.IdRes;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;

import static android.icu.lang.UCharacter.GraphemeClusterBreak.T;

public class Registration_Form extends AppCompatActivity {
    EditText e1, m1, p1, p2, em;
    Button b1;
    CheckBox ch;
    RadioButton r1, r2;
    RadioGroup ra;
    SharedPreferences sharedPreferences;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_registration__form);
        e1 = (EditText) findViewById(R.id.username);
        m1 = (EditText) findViewById(R.id.phone);
        p1 = (EditText) findViewById(R.id.password);
        p2 = (EditText) findViewById(R.id.conpassword);
        em = (EditText) findViewById(R.id.email);
        b1 = (Button) findViewById(R.id.submit);
        ch = (CheckBox) findViewById(R.id.checkedTextView);
        r1 = (RadioButton) findViewById(R.id.male);
        r2 = (RadioButton) findViewById(R.id.female);
        ra = (RadioGroup) findViewById(R.id.radioGroup);

        //sharedPreferences Configuration
        sharedPreferences = getSharedPreferences("Demo", Context.MODE_PRIVATE);

        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if (e1.getText().toString().isEmpty() || e1.getText().toString().length() < 6) {
                    e1.setError("Please Enter At Least 6 Character");
                } else {
                    if (m1.getText().toString().isEmpty() || m1.getText().toString().length() < 10) {
                        m1.setError("Please Enter Correct Mobile Number");
                    } else {
                        if (m1.getText().toString().startsWith("9") || m1.getText().toString().startsWith("8") || m1.getText().toString().startsWith("7")) {
                        } else {
                            Toast.makeText(getApplicationContext(), "Mobile Number Start With 9/8/7 ", Toast.LENGTH_SHORT).show();
                        }
                        if (p1.getText().toString().isEmpty() || p1.getText().toString().length() < 6 || p2.getText().toString().isEmpty() || p2.getText().toString().length() < 6) {
                            Toast.makeText(getApplicationContext(), "Please Enter At Lease 6 Character", Toast.LENGTH_SHORT).show();
                        } else {
                            if (!p1.getText().toString().equals(p2.getText().toString())) {
                                Toast.makeText(getApplicationContext(), "Password Not Matched", Toast.LENGTH_SHORT).show();
                            } else {
                                if (em.getText().toString().isEmpty()) {
                                    em.setError("Please Enter Valid Email");
                                } else {
                                    if (r1.isChecked() == true || r2.isChecked() == true) {
                                        if (ch.isChecked() == true) {
                                            Toast.makeText(getApplicationContext(), "Register Successfully", Toast.LENGTH_SHORT).show();
                                             SharedPreferences.Editor editor = sharedPreferences.edit();
                                                editor.putString("userName", e1.getText().toString());
                                                editor.commit();
                                                Intent login = new Intent(getApplicationContext(),Login.class);
                                                startActivity(login);
                                                finish();
                                        } else {
                                            Toast.makeText(getApplicationContext(), "Please Select The Check Box To Further Proceed", Toast.LENGTH_SHORT).show();
                                        }
                                    } else {
                                        Toast.makeText(getApplicationContext(), "Please Select One Gender", Toast.LENGTH_SHORT).show();
                                    }
                                }

                            }
                        }
                    }
                }
            }
        });
    }
}

2.Login.java

package com.example.android.demo;

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

public class Login extends AppCompatActivity {

    EditText e1,e2;
    Button b1;
    TextView t1;
    SharedPreferences loginShare;
    String myLogin;

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

        e1 = (EditText)findViewById(R.id.username);
        e2 = (EditText)findViewById(R.id.password);
        b1 = (Button) findViewById(R.id.login);
        t1 = (TextView)findViewById(R.id.registrationYourSelf);

        loginShare = getSharedPreferences("Demo", Context.MODE_PRIVATE);
        myLogin = loginShare.getString("userName", null);
        Toast.makeText(getApplicationContext(),myLogin,Toast.LENGTH_LONG);

        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(e1.getText().toString().equals("admin") && e2.getText().toString().equals("admin")){
                    Toast.makeText(getApplicationContext(), "Login Successfully", Toast.LENGTH_SHORT).show();

                    Intent mainpage = new Intent(getApplicationContext(),MainActivity.class);
                    startActivity(mainpage);
                    finish();
                }else {
                    Toast.makeText(getApplicationContext(),"Credentials Not Match",Toast.LENGTH_SHORT).show();
                }
            }
        });


        t1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent registrationForm = new Intent(getApplicationContext(),Registration_Form.class);
                startActivity(registrationForm);
                //finish();
            }
        });
    }

}

Answer 1

在你的Toast中，你最后没有添加.show()。

    Toast.makeText(getApplicationContext(),myLogin,Toast.LENGTH_LONG).show();

Answer 2

你犯了一个非常愚蠢的错误。您尚未添加.show来显示toast。

试试这个：

    ............
    ....................
    loginShare = getSharedPreferences("Demo", Context.MODE_PRIVATE);
    myLogin = loginShare.getString("userName", null);
    Toast.makeText(getApplicationContext(), "Value: " + myLogin,Toast.LENGTH_LONG).show();

SharedPreferences值未转移

2 个答案: