在Android Studio中如何从MySQL数据库中展示项目中的数据？

要在Android Studio中从MySQL数据库展示项目中的数据，你需要遵循以下步骤：

1. 添加MySQL Connector/J依赖项到你的项目的build.gradle文件中：

```groovy
 dependencies {
     implementation 'mysql:mysql-connector-java:8.0.23'
 }
 ```

2. 在AndroidManifest.xml文件中添加INTERNET权限：

```xml
 <uses-permission android:name="android.permission.INTERNET" />
 ```

3. 创建一个用于连接MySQL数据库的类，例如`DatabaseHelper.java`：

```java
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.SQLException;public class DatabaseHelper {
     private static final String URL = "jdbc:mysql://your_server_ip:3306/your_database_name";
     private static final String USERNAME = "your_username";
     private static final String PASSWORD = "your_password";    public static Connection getConnection() {
         Connection connection = null;
         try {
             Class.forName("com.mysql.cj.jdbc.Driver");
             connection = DriverManager.getConnection(URL, USERNAME, PASSWORD);
         } catch (ClassNotFoundException | SQLException e) {
             e.printStackTrace();
         }
         return connection;
     }
 }
 ```

4. 创建一个用于执行SQL查询并返回结果集的类，例如`DataModel.java`：

```java
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.List;public class DataModel {
     private int id;
     private String name;    public DataModel(int id, String name) {
         this.id = id;
         this.name = name;
     }    // Getter and Setter methods for id and name
 }
 ```

5. 在你的主Activity中，使用`DatabaseHelper`类连接到MySQL数据库，并执行查询以获取数据：

```java
 import androidx.appcompat.app.AppCompatActivity;
 import android.os.Bundle;
 import android.widget.ArrayAdapter;
 import android.widget.ListView;import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.Statement;
 import java.util.ArrayList;
 import java.util.List;public class MainActivity extends AppCompatActivity {
     private ListView listView;
     private ArrayAdapter<DataModel> adapter;
     private List<DataModel> dataList;    @Override     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);        listView = findViewById(R.id.listView);
         dataList = new ArrayList<>();
         adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, dataList);
         listView.setAdapter(adapter);        connectToDatabase();
     }    private void connectToDatabase() {
         String query = "SELECT * FROM your_table_name";
         try {
             Connection connection = DatabaseHelper.getConnection();
             Statement statement = connection.createStatement();
             ResultSet resultSet = statement.executeQuery(query);            while (resultSet.next()) {
                 int id = resultSet.getInt("id");
                 String name = resultSet.getString("name");
                 DataModel dataModel = new DataModel(id, name);
                 dataList.add(dataModel);
             }            resultSet.close();
             statement.close();
             connection.close();
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }
 }
 ```

6. 最后，确保你的`activity_main.xml`布局文件中包含一个`ListView`：

```xml
 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout 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"
     android:orientation="vertical"
     tools:context=".MainActivity">    <ListView
         android:id="@+id/listView"
         android:layout_width="match_parent"
         android:layout_height="wrap_content" /></LinearLayout>
 ```

现在，当你运行应用程序时，它将连接到MySQL数据库并从表中获取数据，然后在`ListView`中显示这些数据。