一、如何跳转一个活动
左边的是本活动名称, 右边的是跳转界面活动名称
Intent intent = new Intent(LoginActivity.this, RegisterActivity.class);
startActivity(intent);
finish();
二、如果在不同的界面传递参数
//发送消息
SharedPreferences sharedPreferences = getSharedPreferences("MyPrefs", MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("username", username);
editor.putString("password", password);
editor.apply(); //接收消息
SharedPreferences sharedPreferences = getSharedPreferences("MyPrefs", MODE_PRIVATE);
String savedUsername = sharedPreferences.getString("username", "");
String savedPassword = sharedPreferences.getString("password", "");
三、如何让图片是按钮
<ImageButtonandroid:id="@+id/imageButton"android:layout_width="50dp"android:layout_height="50dp"android:src="@drawable/s7" />
四、登录界面
1、创建一个LoginActivity类,然后创建对应的界面文件.xml
2、注册登录界面,并让登录界面其成为主界面
<activityandroid:name=".LoginActivity"android:exported="true"><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.LAUNCHER" /></intent-filter></activity><activity android:name=".MainActivity"/><activity android:name=".RegisterActivity"/>
3、书写登录界面
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"><TextViewandroid:layout_width="wrap_content"android:layout_height="20dp"/><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="horizontal"android:gravity="center"><TextViewandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="账号:"android:textSize="20dp"/><EditTextandroid:id="@+id/usernameEditText"android:layout_width="180dp"android:layout_height="wrap_content"android:textSize="20dp"/></LinearLayout><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="horizontal"android:gravity="center"><TextViewandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="密码:"android:textSize="20dp"/><EditTextandroid:id="@+id/passwordEditText"android:layout_width="180dp"android:layout_height="wrap_content"android:textSize="20dp"/></LinearLayout><TextViewandroid:layout_width="wrap_content"android:layout_height="20dp"/><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="horizontal"android:gravity="center"><CheckBoxandroid:id="@+id/rememberPasswordCheckbox"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="记住密码"android:layout_gravity="start"android:layout_marginStart="16dp"android:layout_marginTop="8dp"/><TextViewandroid:layout_width="80dp"android:layout_height="wrap_content"/><Buttonandroid:id="@+id/zcButton"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="点击注册" /></LinearLayout><TextViewandroid:layout_width="wrap_content"android:layout_height="20dp"/><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="horizontal"android:gravity="center"><Buttonandroid:id="@+id/loginButton"android:layout_width="200dp"android:layout_height="wrap_content"android:text="确认登录" /></LinearLayout></LinearLayout>
4、书写登录活动代码
package com.example.yaodian;import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.EditText;
import android.widget.Toast;import androidx.appcompat.app.AppCompatActivity;public class LoginActivity extends AppCompatActivity {EditText usernameEditText;EditText passwordEditText;Button loginButton;Button zcButton;CheckBox rememberPasswordCheckbox ;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.login);rememberPasswordCheckbox = findViewById(R.id.rememberPasswordCheckbox);usernameEditText = findViewById(R.id.usernameEditText);passwordEditText = findViewById(R.id.passwordEditText);loginButton = findViewById(R.id.loginButton);zcButton = findViewById(R.id.zcButton);loginButton.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {String inputUsername = usernameEditText.getText().toString();String inputPassword = passwordEditText.getText().toString();SharedPreferences sharedPreferences = getSharedPreferences("MyPrefs", MODE_PRIVATE);String savedUsername = sharedPreferences.getString("username", "");String savedPassword = sharedPreferences.getString("password", "");// 在这里添加登录验证逻辑if (inputUsername.equals(savedUsername) && inputPassword.equals(savedPassword)) {Toast.makeText(LoginActivity.this, "登录成功", Toast.LENGTH_SHORT).show();Intent intent = new Intent(LoginActivity.this, MainActivity.class);startActivity(intent);finish();// 跳转到 MainActivity 或其他操作} else {new AlertDialog.Builder(LoginActivity.this).setTitle("提示").setMessage("登录失败,用户名或密码错误").setPositiveButton("确定", new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {}}).show();}}});zcButton.setOnClickListener((l) -> {Intent intent = new Intent(LoginActivity.this, RegisterActivity.class);startActivity(intent);finish();});// // 监听复选框状态变化
// rememberPasswordCheckbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
// @Override
// public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// // 根据复选框状态来处理记住密码逻辑
// if (isChecked) {
//
// } else {
//
// }
// }
// });}
}
五、注册界面
同登录界面
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"><TextViewandroid:layout_width="wrap_content"android:layout_height="20dp"/><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="horizontal"android:gravity="center"><TextViewandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text=" 账号:"android:textSize="20dp"/><EditTextandroid:id="@+id/usernameEditText"android:layout_width="180dp"android:layout_height="wrap_content"android:textSize="20dp"/></LinearLayout><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="horizontal"android:gravity="center"><TextViewandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text=" 密码:"android:textSize="20dp"/><EditTextandroid:id="@+id/passwordEditText"android:layout_width="180dp"android:layout_height="wrap_content"android:textSize="20dp"/></LinearLayout><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="horizontal"android:gravity="center"><TextViewandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="确认密码:"android:textSize="20dp"/><EditTextandroid:id="@+id/password2EditText"android:layout_width="180dp"android:layout_height="wrap_content"android:textSize="20dp"/></LinearLayout><TextViewandroid:layout_width="wrap_content"android:layout_height="50dp"/><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="horizontal"android:gravity="center"><Buttonandroid:id="@+id/registerButton"android:layout_width="200dp"android:layout_height="wrap_content"android:text="确认注册" /></LinearLayout></LinearLayout>
package com.example.yaodian;import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;import androidx.appcompat.app.AppCompatActivity;public class RegisterActivity extends AppCompatActivity {private EditText usernameEditText;private EditText passwordEditText;private EditText password2EditText;private Button registerButton;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.register_activity);usernameEditText = findViewById(R.id.usernameEditText);passwordEditText = findViewById(R.id.passwordEditText);password2EditText = findViewById(R.id.password2EditText);registerButton = findViewById(R.id.registerButton);registerButton.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {String username = usernameEditText.getText().toString().trim();String password = passwordEditText.getText().toString().trim();String password2 = password2EditText.getText().toString().trim();if (username.isEmpty() || password.isEmpty()) {// 弹出“请输入账号和密码”的对话框new AlertDialog.Builder(RegisterActivity.this).setTitle("提示").setMessage("请输入账号和密码").setPositiveButton("确定", null).show();} else if (!password.equals(password2)) {// 弹出“两次密码不一样,请重新输入”的对话框new AlertDialog.Builder(RegisterActivity.this).setTitle("提示").setMessage("两次密码不一样,请重新输入").setPositiveButton("确定", new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// 清空密码和确认密码输入框passwordEditText.setText("");password2EditText.setText("");}}).show();} else {// 保存注册信息到 SharedPreferencesSharedPreferences sharedPreferences = getSharedPreferences("MyPrefs", MODE_PRIVATE);SharedPreferences.Editor editor = sharedPreferences.edit();editor.putString("username", username);editor.putString("password", password);editor.apply();Toast.makeText(RegisterActivity.this, "注册成功", Toast.LENGTH_SHORT).show();Intent intent = new Intent(RegisterActivity.this, LoginActivity.class);startActivity(intent);finish();}}});}
}
六、完整工程代码
链接:https://pan.baidu.com/s/13tm-AsAsJEmfJjbwyX0a3Q
提取码:生日
需要提取码的 加QQ:1482728006,说明来意,付费即可获取工程