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