android 用户登录及记录密码功能

1、下面是登陆界面

代码如下：

<RelativeLayout 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:id="@+id/activity_login"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:background="@drawable/loginbg"
    tools:context="cn.edu.bzu.case_login.LoginActivity">

    <include
        layout="@layout/login_top"
        android:id="@+id/include"></include>

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:srcCompat="@drawable/deer"
        android:layout_marginBottom="29dp"
        android:id="@+id/imageView"
        android:layout_marginRight="21dp"
        android:layout_marginEnd="21dp"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true" />
</RelativeLayout>

2、欢迎界面

代码如下：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:textSize="40sp"
        android:text="Welcome you" />

</RelativeLayout>

3、用户名密码输入界面，上面那个界面只是显示用的，这个才是真正处理数据的。

代码如下：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/logintop_roundbg"
    android:padding="@dimen/activity_horizontal_margin"
    >

    <EditText
        android:id="@+id/etName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@android:drawable/edit_text"
        android:drawableLeft="@drawable/icon_user"
        android:drawablePadding="10dp"
        android:ems="10"
        android:hint="@string/etName">

        <requestFocus />
    </EditText>

    <EditText
        android:id="@+id/etPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/etName"
        android:background="@android:drawable/edit_text"
        android:drawableLeft="@drawable/icon_pass"
        android:drawablePadding="10dp"
        android:ems="10"
        android:hint="@string/etPass"
        android:inputType="textPassword">

        <requestFocus />
    </EditText>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/etPassword">

        <CheckBox
            android:id="@+id/cbIsRememberPass"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="@string/cbIsRememberPass"
            android:textSize="20sp"/>

        <Button
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:background="@drawable/btn_select"
            android:text="@string/btnLogin"
            android:onClick="login" />

    </LinearLayout>
</RelativeLayout>

4、mainActivity

代码如下：

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

5、LoginActivity登录java文件，判断是否选中记住密码，然后执行不同命令。

代码如下：

public class LoginActivity extends AppCompatActivity {

    private EditText etName;
    private EditText etPassword;
    private CheckBox cbIsRememberPass;
    private SharedPreferences sharedPreferences;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        initViews();
        sharedPreferences = getSharedPreferences("rememberpassword", Context.MODE_PRIVATE);
        boolean isRemember = sharedPreferences.getBoolean("rememberpassword", false);
        if (isRemember) {
            String name = sharedPreferences.getString("name", "");
            String password = sharedPreferences.getString("password", "");
            etName.setText(name);
            etPassword.setText(password);
            cbIsRememberPass.setChecked(true);
        }
    }

    public void initViews() {
        etName = (EditText) findViewById(R.id.etName);
        etPassword = (EditText) findViewById(R.id.etPassword);
        cbIsRememberPass = (CheckBox) findViewById((R.id.cbIsRememberPass));
    }

    public void login(View view) {
        String name = etName.getText().toString();
        String password = etPassword.getText().toString();
        if ("admin".equals(name) && "123456".equals(password)) {
            SharedPreferences.Editor editor = sharedPreferences.edit();
            if (cbIsRememberPass.isChecked()) {
                editor.putBoolean("rememberpassword", true);
                editor.putString("name", name);
                editor.putString("password", password);
            } else {
                editor.clear();
            }
            editor.commit();
            Intent intent = new Intent(this, MainActivity.class);
            startActivity(intent);
            finish();
        } else {
            Toast.makeText(this, "账号或密码有误", Toast.LENGTH_SHORT).show();
        }
    }
}

运行结果：首先第一次登陆会这样

如果选择记住密码

下次打开时会如下界面：

可以直接登陆

如果选择不记住密码则需要重新输入

界面如下