Android大作業功能設計之自動登入和記住密碼

// 存資料
SharedPreferences sp = getSharedPrefrences("data", MODE_PRIVATE);// 獲取sharedPreferenced物件
SharedPreferences.Editor ed = sp.edit();// 獲取SharePreferenced.Editor物件
ed.putString("name", "Sam");// 向SharePreferenced.Editor物件新增資料
ed.apply();// 呼叫apply()提交資料，就是儲存的意思
// 取資料
SharedPrefrences sp = getSharedPrefrences("data",MODE_PRIVATE);
String name = sp.getString("name","");// 取資料

public class HomeActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home);
  }
}

	<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
	xmlns:android="http://schemas.android.com/apk/res/android"
	xmlns:app="http://schemas.android.com/apk/res-auto"
	xmlns:tools="http://schemas.android.com/tools"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	tools:context=".HomeActivity">
	<TextView
    	android:id="@+id/tv_text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/text"
    android:textSize="26sp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

	private AppCompatEditText edit_account,  edit_password;
	private CheckBox cb_remember, cb_autologin;
	private SharedPreferences sharedPreferences;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
    	super.onCreate(savedInstanceState);
    	setContentView(R.layout.activity_main);
    	bindView();
    	initView();
	}
	/**
 	*用於繫結控制元件id的方法
 	*/
	protected void bindView() {
    	edit_account = findViewById(R.id.edit_account);
    	edit_password = findViewById(R.id.edit_password);
    	cb_remember = findViewById(R.id.cb_remember);
    	cb_remember.setOnCheckedChangeListener(this);
    	cb_autologin = findViewById(R.id.cb_autologin);
    	cb_autologin.setOnCheckedChangeListener(this);
    	Button btn_login = findViewById(R.id.btn_login);
    	btn_login.setOnClickListener(this);
    	// 獲取SharedPreferences的範例
    	sharedPreferences = this.getSharedPreferences("loginInfo", MODE_PRIVATE);
	}
	/**
 	* 用於初始化介面
 	*/
	protected void initView() {
		// 獲取sharedPreferences中remember對於的boolean值，true表示記住密碼
    	if (sharedPreferences.getBoolean("remember", false)) {
        	cb_remember.setChecked(true);
        	edit_account.setText(sharedPreferences.getString("account", ""));
        	edit_password.setText(sharedPreferences.getString("password",""));
        	autologin();
    	}
	}
	// 登入按鈕的邏輯
	@Override
	public void onClick(View view) {
    	// 定義賬號和密碼的字串
    	String account, password;
    	// 判斷賬號是否為空
    	if (edit_account.getText() == null) {
        	showToast("賬號為空,請重新輸入");
        	return;
    	}
    	// 判斷密碼是否為空
    	if (edit_password.getText() == null) {
        	showToast("密碼為空,請重新輸入");
        	return;
    	}
    	// 賬號和密碼都不為空,進行密碼賬號校驗
    	account = edit_account.getText().toString().trim();
    	password = edit_password.getText().toString().trim();
    	// 此處固定了賬號和密碼
    	if (account.equals("admin") && password.equals("12345")) {
        	if (cb_remember.isChecked()) {
            	SharedPreferences.Editor editor = sharedPreferences.edit();
            	editor.putString("account", account);
            	editor.putString("password", password);
            	editor.apply();
        	}
        	showToast("登入成功");
        	Intent intent = new Intent(MainActivity.this, HomeActivity.class);// 跳轉到主介面
        	startActivity(intent);
//            finish();
    	}
	}
	/**
 	* 自動登入邏輯
 	*/
	private void autologin() {
    	// 獲取sharedPreferences中autologin對於的boolean值, true表示記住密碼
    	if (sharedPreferences.getBoolean("autologin", false)) {
        	// 勾選自動登入
        	cb_autologin.setChecked(true);
        	// 跳轉頁面
       		Intent intent = new Intent(MainActivity.this, HomeActivity.class);// 跳轉到主介面
        	startActivity(intent);
    	}
	}
	/**
 	* 用於顯示toast彈出訊息
 	* @param text 需要顯示的文字
 	*/
	private void showToast(final String text) {
    	Toast.makeText(MainActivity.this, text, Toast.LENGTH_SHORT).show();
	}
	// checkButton按鈕的選中監聽事件,compoundButton指的是checkButton控制元件， isChecked指的是是否勾選
	@SuppressLint("NonConstantResourceId")
	@Override
	public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {
    	switch (compoundButton.getId()) {
        	case R.id.cb_remember:
            	if (isChecked) {
                	sharedPreferences.edit().putBoolean("remember", true).apply();
            	} else {
                	sharedPreferences.edit().putBoolean("remember", false).apply();
            	}
            	break;
        	case R.id.cb_autologin:
            	if (isChecked) {
                	sharedPreferences.edit().putBoolean("autologin", true).apply();
            	} else {
                	sharedPreferences.edit().putBoolean("autologin", false).apply();
            	}
            	break;
    	}
	}

<?xml version='1.0' encoding='utf-8' standalone='yes' ?>
<map>
	<boolean name="remember" value="true" />
	<boolean name="autologin" value="true" />
	<string name="password">12345</string>
	<string name="account">admin</string>
</map>