Android之记住密码与自动登陆实现

本文主要讲述了利用sharedpreference实现记住密码与自动登陆功能

1. 根据checkbox的状态存储用户名与密码
2. 将结果保存在自定义的application中，成为全局变量

布局文件

<?xml version="1.0" encoding="utf-8"?><ScrollView xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:fitsSystemWindows="true">    <LinearLayout        android:orientation="vertical"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:paddingTop="56dp"        android:paddingLeft="24dp"        android:paddingRight="24dp">        <ImageView android:src="@drawable/logo"            android:layout_width="wrap_content"            android:layout_height="72dp"            android:layout_marginBottom="24dp"            android:layout_gravity="center_horizontal" />        <!--  Email Label -->        <android.support.design.widget.TextInputLayout            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_marginTop="8dp"            android:layout_marginBottom="8dp">            <EditText android:id="@+id/input_email"                android:layout_width="match_parent"                android:layout_height="wrap_content"                android:inputType="textEmailAddress"                android:hint="Phone" />        </android.support.design.widget.TextInputLayout>        <!--  Password Label -->        <android.support.design.widget.TextInputLayout            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_marginTop="8dp"            android:layout_marginBottom="8dp">            <EditText android:id="@+id/input_password"                android:layout_width="match_parent"                android:layout_height="wrap_content"                android:inputType="textPassword"                android:hint="Password"/>        </android.support.design.widget.TextInputLayout>        <LinearLayout            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:orientation="horizontal"            android:gravity="center_horizontal"            >            <CheckBox                android:id="@+id/rm_pass"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:text="记住密码"                android:layout_marginRight="30dp"                android:checked="true"                />            <CheckBox                android:id="@+id/au_login"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:text="自动登陆"                android:layout_marginLeft="30dp"                />        </LinearLayout>        <android.support.v7.widget.AppCompatButton            android:id="@+id/btn_login"            android:layout_width="fill_parent"            android:layout_height="wrap_content"            android:layout_marginTop="24dp"            android:layout_marginBottom="24dp"            android:padding="12dp"            android:text="Login"/>        <TextView android:id="@+id/link_signup"            android:layout_width="fill_parent"            android:layout_height="wrap_content"            android:layout_marginBottom="24dp"            android:text="No account yet? Create one"            android:gravity="center"            android:textSize="16dip"/>    </LinearLayout></ScrollView>

登陆界面

package com.zj.login;import android.app.Activity;import android.app.ProgressDialog;import android.content.Intent;import android.content.SharedPreferences;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.util.Patterns;import android.view.View;import android.widget.Button;import android.widget.CheckBox;import android.widget.EditText;import android.widget.TextView;import android.widget.Toast;import com.zj.cafetriafood.R;import butterknife.Bind;import butterknife.ButterKnife;/** * A login screen that offers login via email/password. */public class LoginActivity extends AppCompatActivity  {    private static final String TAG = "LoginActivity";    private static final int REQUEST_SIGNUP = 0;    private SharedPreferences sp;    @Bind(R.id.input_email) EditText _emailText;    @Bind(R.id.input_password) EditText _passwordText;    @Bind(R.id.btn_login) Button _loginButton;    @Bind(R.id.link_signup) TextView _signupLink;    @Bind(R.id.rm_pass) CheckBox _rmpass;    @Bind(R.id.au_login) CheckBox _aulogin;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_login);        ButterKnife.bind(this);        sp = this.getSharedPreferences("userInfo", Activity.MODE_PRIVATE);        _loginButton.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                login();            }        });        _signupLink.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                // Start the Signup activity                Intent intent = new Intent(getApplicationContext(), SignupActivity.class);                startActivityForResult(intent, REQUEST_SIGNUP);            }        });        if(sp.getBoolean("ISCHECK", false))        {            _rmpass.setChecked(true);            _emailText.setText(sp.getString("USER_NAME", ""));            _passwordText.setText(sp.getString("PASSWORD", ""));            if(sp.getBoolean("AUTO_ISCHECK", false))            {                //设置默认是自动登录状态                _aulogin.setChecked(true);                //跳转界面                //Intent intent = new Intent(LoginActivity.this,MainActivity.class);                //startActivity(intent);                this.finish();            }        }    }    public void login() {        Log.d(TAG, "Login");        if (!validate()) {            onLoginFailed();            return;        }        _loginButton.setEnabled(false);        final ProgressDialog progressDialog = new ProgressDialog(LoginActivity.this,                R.style.AppTheme_Dark_Dialog);        progressDialog.setIndeterminate(true);        progressDialog.setMessage("Authenticating...");        progressDialog.show();        String email = _emailText.getText().toString();        String password = _passwordText.getText().toString();        // TODO: Implement your own authentication logic here.        Log.i("test","email+password="+email+","+password);        if(!email.equals("123")||!password.equals("123456"))        {            progressDialog.dismiss();            _loginButton.setEnabled(true);            _emailText.setText("");            _passwordText.setText("");            Toast.makeText(getApplication(), "用户名或密码错误", Toast.LENGTH_SHORT).show();            return;        }        if(_rmpass.isChecked())        {            //记住用户名、密码、            SharedPreferences.Editor editor = sp.edit();            editor.putString("USER_NAME", email);            editor.putString("PASSWORD", password);            editor.commit();            sp.edit().putBoolean("ISCHECK", true).commit();        }else        {            sp.edit().putBoolean("ISCHECK", true).commit();        }        if (_aulogin.isChecked())        {            sp.edit().putBoolean("AUTO_ISCHECK", true).commit();        }else        {            sp.edit().putBoolean("AUTO_ISCHECK", false).commit();        }            new android.os.Handler().postDelayed(                new Runnable() {                    public void run() {                        // On complete call either onLoginSuccess or onLoginFailed                        onLoginSuccess();                        // onLoginFailed();                        progressDialog.dismiss();                    }                }, 3000);    }    @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        if (requestCode == REQUEST_SIGNUP) {            if (resultCode == RESULT_OK) {                // TODO: Implement successful signup logic here                // By default we just finish the Activity and log them in automatically                this.finish();            }        }    }    @Override    public void onBackPressed() {        // Disable going back to the MainActivity        moveTaskToBack(true);    }    public void onLoginSuccess() {        _loginButton.setEnabled(true);        finish();    }    public void onLoginFailed() {        Toast.makeText(getBaseContext(), "Login failed", Toast.LENGTH_LONG).show();        _loginButton.setEnabled(true);    }    public boolean validate() {        boolean valid = true;        String email = _emailText.getText().toString();        String password = _passwordText.getText().toString();        if (email.isEmpty() || !Patterns.PHONE.matcher(email).matches()) {            _emailText.setError("enter a valid phone number");            valid = false;        } else {            _emailText.setError(null);        }        if (password.isEmpty() || password.length() < 4 || password.length() > 10) {            _passwordText.setError("between 4 and 10 alphanumeric characters");            valid = false;        } else {            _passwordText.setError(null);        }        return valid;    }}

MainActivity

package com.zj.cafetriafood;import android.app.Activity;import android.content.Intent;import android.content.SharedPreferences;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.widget.TextView;import com.zj.application.MyApplication;import com.zj.login.LoginActivity;import butterknife.Bind;import butterknife.ButterKnife;public class MainActivity extends AppCompatActivity {    private SharedPreferences sp;    private MyApplication myApplication;    @Bind(R.id.text_user) TextView text_user;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ButterKnife.bind(this);        sp = this.getSharedPreferences("userInfo", Activity.MODE_PRIVATE);        if(sp.getBoolean("AUTO_ISCHECK", false))        {            myApplication= (MyApplication) getApplication();            myApplication.setUsername(sp.getString("USER_NAME",""));        }else        {            Intent intent = new Intent(this, LoginActivity.class);            startActivity(intent);        }        text_user.setText(myApplication.getUsername());    }}

MyApplication

package com.zj.application;import android.app.Application;/** * Created by jjx on 2016/5/22. */public class MyApplication extends Application{    public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }    String username;    @Override    public void onCreate() {        super.onCreate();        setUsername("用户名");    }}

参考链接

Android 记住密码和自动登录界面的实现（SharedPreferences 的用法） - liuyiming_的专栏 - 博客频道 - CSDN.NET

Android中Application类用法 - Harvey Ren - 博客园

Application对象的生命周期是整个程序中最长的，它的生命周期就等于这个程序的生命周期。因为它是全局的单例的，所以在不同的Activity,Service中获得的对象都是同一个对象。所以可以通过Application来进行一些，如：数据传递、数据共享和数据缓存等操作。

在Android中，可以通过继承Application类来实现应用程序级的全局变量，这种全局变量方法相对静态类更有保障，直到应用的所有Activity全部被destory掉之后才会被释放掉。

效果如下