String username =et_user.getText().toString();
时间: 2024-06-02 20:08:12 浏览: 22
这段代码是从一个 Android 应用中获取用户输入的用户名(username)并将其转换为字符串,前提是在布局文件中有一个名为 et_user 的 EditText 控件。getText() 方法将 EditText 中的文本内容获取为 Editable 对象,而 toString() 方法将其转换为字符串类型。
相关问题
Android stdio 用代码实现,用户注册账号密码登陆。其中布局文件已经给出有两个EditText和两个Button和一个CheckBox组成。要求注册账号密码时,如果当前账号密码没有注册过则可以注册成功,否则注册失败。 登陆账号密码时会和注册的账号密码比对,如果相同则登陆成功,否则登陆失败。 CheckBox如果被赋予true,则下次打开软件时自动填充账号密码。 最终将代码以一个xml和一个Activity的格式给出
下面是实现该功能的代码:
activity_main.xml:
```
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="@dimen/activity_horizontal_margin"
tools:context=".MainActivity">
<EditText
android:id="@+id/et_username"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="@string/username"/>
<EditText
android:id="@+id/et_password"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/et_username"
android:hint="@string/password"
android:inputType="textPassword"/>
<Button
android:id="@+id/btn_register"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/et_password"
android:layout_alignParentStart="true"
android:text="@string/register"/>
<Button
android:id="@+id/btn_login"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/et_password"
android:layout_alignParentEnd="true"
android:text="@string/login"/>
<CheckBox
android:id="@+id/cb_remember"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/btn_register"
android:text="@string/remember"/>
</RelativeLayout>
```
MainActivity.java:
```
import android.content.Context;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private EditText et_username;
private EditText et_password;
private Button btn_register;
private Button btn_login;
private CheckBox cb_remember;
private SharedPreferences sp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_username = (EditText) findViewById(R.id.et_username);
et_password = (EditText) findViewById(R.id.et_password);
btn_register = (Button) findViewById(R.id.btn_register);
btn_login = (Button) findViewById(R.id.btn_login);
cb_remember = (CheckBox) findViewById(R.id.cb_remember);
sp = getSharedPreferences("user", Context.MODE_PRIVATE);
btn_register.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String username = et_username.getText().toString();
String password = et_password.getText().toString();
if (username.isEmpty() || password.isEmpty()) {
Toast.makeText(MainActivity.this, R.string.empty_input, Toast.LENGTH_SHORT).show();
} else {
if (sp.contains(username)) {
Toast.makeText(MainActivity.this, R.string.username_exist, Toast.LENGTH_SHORT).show();
} else {
sp.edit().putString(username, password).apply();
Toast.makeText(MainActivity.this, R.string.register_success, Toast.LENGTH_SHORT).show();
}
}
}
});
btn_login.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String username = et_username.getText().toString();
String password = et_password.getText().toString();
if (username.isEmpty() || password.isEmpty()) {
Toast.makeText(MainActivity.this, R.string.empty_input, Toast.LENGTH_SHORT).show();
} else {
if (sp.contains(username)) {
if (password.equals(sp.getString(username, ""))) {
Toast.makeText(MainActivity.this, R.string.login_success, Toast.LENGTH_SHORT).show();
if (cb_remember.isChecked()) {
sp.edit().putString("last_user", username).apply();
}
} else {
Toast.makeText(MainActivity.this, R.string.password_error, Toast.LENGTH_SHORT).show();
}
} else {
Toast.makeText(MainActivity.this, R.string.username_not_exist, Toast.LENGTH_SHORT).show();
}
}
}
});
String lastUser = sp.getString("last_user", "");
if (!lastUser.isEmpty()) {
et_username.setText(lastUser);
et_password.setText(sp.getString(lastUser, ""));
cb_remember.setChecked(true);
}
}
}
```
strings.xml:
```
<resources>
<string name="app_name">UserLogin</string>
<string name="username">Username</string>
<string name="password">Password</string>
<string name="register">Register</string>
<string name="login">Login</string>
<string name="remember">Remember me</string>
<string name="empty_input">Username or password cannot be empty</string>
<string name="username_exist">Username already exists</string>
<string name="register_success">Register successful</string>
<string name="login_success">Login successful</string>
<string name="password_error">Password incorrect</string>
<string name="username_not_exist">Username not exist</string>
</resources>
```
在Android Studio中实验账号的注册,登录,查看,修改的java代码和xml代码
以下是一个简单的Android Studio项目,其中包含了账号的注册、登录、查看和修改功能的Java代码和XML布局文件。
1. 注册页面(RegisterActivity.java)
```
public class RegisterActivity extends AppCompatActivity {
private EditText etUsername, etPassword, etConfirmPassword;
private Button btnRegister;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
etUsername = findViewById(R.id.et_username);
etPassword = findViewById(R.id.et_password);
etConfirmPassword = findViewById(R.id.et_confirm_password);
btnRegister = findViewById(R.id.btn_register);
btnRegister.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String username = etUsername.getText().toString().trim();
String password = etPassword.getText().toString().trim();
String confirmPassword = etConfirmPassword.getText().toString().trim();
if (TextUtils.isEmpty(username)) {
etUsername.setError("Username is required!");
return;
}
if (TextUtils.isEmpty(password)) {
etPassword.setError("Password is required!");
return;
}
if (!password.equals(confirmPassword)) {
etConfirmPassword.setError("Passwords do not match!");
return;
}
// TODO: Register the user and save the data in the database
}
});
}
}
```
对应的XML布局文件(activity_register.xml)如下:
```
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="16dp">
<EditText
android:id="@+id/et_username"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Username" />
<EditText
android:id="@+id/et_password"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Password"
android:inputType="textPassword" />
<EditText
android:id="@+id/et_confirm_password"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Confirm Password"
android:inputType="textPassword" />
<Button
android:id="@+id/btn_register"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Register" />
</LinearLayout>
```
2. 登录页面(LoginActivity.java)
```
public class LoginActivity extends AppCompatActivity {
private EditText etUsername, etPassword;
private Button btnLogin;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
etUsername = findViewById(R.id.et_username);
etPassword = findViewById(R.id.et_password);
btnLogin = findViewById(R.id.btn_login);
btnLogin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String username = etUsername.getText().toString().trim();
String password = etPassword.getText().toString().trim();
if (TextUtils.isEmpty(username)) {
etUsername.setError("Username is required!");
return;
}
if (TextUtils.isEmpty(password)) {
etPassword.setError("Password is required!");
return;
}
// TODO: Authenticate the user and start the app
}
});
}
}
```
对应的XML布局文件(activity_login.xml)如下:
```
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="16dp">
<EditText
android:id="@+id/et_username"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Username" />
<EditText
android:id="@+id/et_password"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Password"
android:inputType="textPassword" />
<Button
android:id="@+id/btn_login"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Login" />
</LinearLayout>
```
3. 查看页面(ProfileActivity.java)
```
public class ProfileActivity extends AppCompatActivity {
private TextView tvUsername, tvPassword;
private Button btnEdit;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_profile);
tvUsername = findViewById(R.id.tv_username);
tvPassword = findViewById(R.id.tv_password);
btnEdit = findViewById(R.id.btn_edit);
// TODO: Get the user data from the database and populate the textviews
btnEdit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO: Start the edit profile activity
}
});
}
}
```
对应的XML布局文件(activity_profile.xml)如下:
```
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="16dp">
<TextView
android:id="@+id/tv_username"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Username: " />
<TextView
android:id="@+id/tv_password"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Password: " />
<Button
android:id="@+id/btn_edit"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Edit Profile" />
</LinearLayout>
```
4. 修改页面(EditProfileActivity.java)
```
public class EditProfileActivity extends AppCompatActivity {
private EditText etUsername, etPassword, etConfirmPassword;
private Button btnSave;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_edit_profile);
etUsername = findViewById(R.id.et_username);
etPassword = findViewById(R.id.et_password);
etConfirmPassword = findViewById(R.id.et_confirm_password);
btnSave = findViewById(R.id.btn_save);
// TODO: Get the user data from the database and populate the edittexts
btnSave.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String username = etUsername.getText().toString().trim();
String password = etPassword.getText().toString().trim();
String confirmPassword = etConfirmPassword.getText().toString().trim();
if (TextUtils.isEmpty(username)) {
etUsername.setError("Username is required!");
return;
}
if (TextUtils.isEmpty(password)) {
etPassword.setError("Password is required!");
return;
}
if (!password.equals(confirmPassword)) {
etConfirmPassword.setError("Passwords do not match!");
return;
}
// TODO: Update the user data in the database
}
});
}
}
```
对应的XML布局文件(activity_edit_profile.xml)如下:
```
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="16dp">
<EditText
android:id="@+id/et_username"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Username" />
<EditText
android:id="@+id/et_password"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Password"
android:inputType="textPassword" />
<EditText
android:id="@+id/et_confirm_password"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Confirm Password"
android:inputType="textPassword" />
<Button
android:id="@+id/btn_save"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Save Changes" />
</LinearLayout>
```
请注意,上面的代码是只是一个简单的示例,实际情况下,您需要根据您的应用程序的需求进行更改和修改。