安卓大作业-开黑盒子，高分课程设计，可一键运行

package com.example.myexamproject; import androidx.appcompat.app.AppCompatActivity; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.os.Bundle; import android.text.TextUtils; 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.example.myexamproject.utils.MD5Utils; public class LoginActivity extends AppCompatActivity { //声明所有按钮 private Button login; private TextView tv_register; private EditText et_username,et_pwd; private CheckBox save_pwd; private String userName,passWord,spPsw; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_login); init(); } private void init() { //给所有按钮匹配id et_username = (EditText) findViewById(R.id.username); et_pwd = (EditText) findViewById(R.id.pwd); save_pwd = (CheckBox) findViewById(R.id.save_pwd); login = (Button)findViewById(R.id.loginBtn); tv_register = (TextView) findViewById(R.id.register); //获取记住的账号密码 getUserInfo(); //登录方法 login.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { getEditString(); //对当前用户输入的密码进行MD5加密再进行比对判断。 String md5Psw= MD5Utils.md5(passWord); // 定义方法 readPsw为了读取用户名，得到密码 spPsw = readPsw(userName); if(TextUtils.isEmpty(userName)){ Toast.makeText( LoginActivity.this, "请输入用户名", Toast.LENGTH_SHORT).show(); return; }else if(TextUtils.isEmpty(passWord)){ Toast.makeText( LoginActivity.this, "请输入密码", Toast.LENGTH_SHORT).show(); return; // md5Psw.equals(); 判断密码是否与注册的一致 }else if(md5Psw.equals(spPsw)){ //一致登录成功 Toast.makeText( LoginActivity.this, "welcome！"+ userName, Toast.LENGTH_SHORT).show(); //保存登录状态，在界面保存登录的用户名和密码 saveLoginInfo(userName,passWord); saveLoginStatus(true, userName); //登录成功后关闭此页面进入主页 Intent data = new Intent(); data.putExtra("isLogin",true); setResult(RESULT_OK,data); //关闭登录界面 LoginActivity.this.finish(); //跳转到下一个界面 startActivity(new Intent( LoginActivity.this, MainActivity.class)); return; //如果用户名或者账号错误会提示错误 }else if((spPsw!=null&&!TextUtils.isEmpty(spPsw)&&!md5Psw.equals(spPsw))){ Toast.makeText( LoginActivity.this, "密码错误", Toast.LENGTH_SHORT).show(); return; }else{ Toast.makeText( LoginActivity.this, "此用户名不存在", Toast.LENGTH_SHORT).show(); } } }); tv_register.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //跳转到注册界面 Intent intent=new Intent( LoginActivity.this,RegisterActivity.class); startActivity(intent); LoginActivity.this.finish(); } }); } //获取用户名和密码 private void getEditString(){ userName = et_username.getText().toString().trim(); passWord = et_pwd.getText().toString().trim(); } //保存登录信息 public void saveLoginInfo(String userName, String passWord){ //获取SharedPreferences对象 boolean CheckBoxLogin = save_pwd.isChecked(); SharedPreferences sp = getSharedPreferences("userInfo", MODE_PRIVATE); SharedPreferences.Editor editor = sp.edit(); //设置参数 if (CheckBoxLogin){ editor.putString("username", userName); editor.putString("password", passWord); editor.putBoolean("checkboxBoolean",true); editor.commit(); }else { editor.putString("username", null); editor.putString("password", null); editor.putBoolean("checkboxBoolean", false); editor.commit(); } } //从已经存入的对象中读取密码 private String readPsw(String userName){ SharedPreferences sp = getSharedPreferences("loginInfo", MODE_PRIVATE); return sp.getString(userName , ""); } //保存登录状态 private void saveLoginStatus(boolean status,String userName){ SharedPreferences sp = getSharedPreferences("loginInfo", MODE_PRIVATE); SharedPreferences.Editor editor = sp.edit(); editor.putBoolean("isLogin", status); editor.putString("loginUserName", userName); editor.commit(); } //返回注册成功数据 protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); if(data!=null){ String userName=data.getStringExtra("userName"); if(!TextUtils.isEmpty(userName)){ et_username.setText(userName); et_username.setSelection(userName.length()); } } } //获得用户已注册的信息 public void getUserInfo(){ SharedPreferences sp = null; sp = this.getSharedPreferences("userInfo", Context.MODE_PRIVATE); if (sp.getBoolean("checkboxBoolean", false)) { et_username.setText(sp.getString("username", null)); et_pwd.setText(sp.getString("password", null)); save_pwd.setChecked(true); }else{ et_username.setText(sp.getString("username", userName)); et_pwd.setText(sp.getString("password", passWord)); save_pwd.setChecked(false); } } public void onBackPressed() { LoginActivity.this.finish(); } }