如何在 Android ListView 中检测向上和向下滚动?
androidapps/applicationsmobile development更新于 2026/2/16 11:22:17
此示例演示了如何在 Android ListView 中检测向上和向下滚动。
步骤 1 − 在 Android Studio 中创建一个新项目，转到"文件"->"新建项目"，并填写所有必需的详细信息以创建新项目。
步骤 2 − 将以下代码添加到 res/layout/activity_main.xml。
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:gravity="center" android:padding="8dp" tools:context=".MainActivity"> <ListView android:id="@+id/listView" android:layout_width="match_parent" android:layout_height="match_parent"/> </LinearLayout>
步骤 3 − 将以下代码添加到 src/MainActivity.java
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.AbsListView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.ScrollView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
ScrollView scrollView;
ListView listView;
String[] numbers = {"1","2","3","4", "5","6","7","8", "9", "X", "11", "12", "13", "14", "15", "16", "17", "18", "19", "20" , "21", "22", "23", "24", "25"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
scrollView = findViewById(R.id.scrollView);
ArrayAdapter adapter = new ArrayAdapter<>(this,
R.layout.support_simple_spinner_dropdown_item, numbers);
listView = findViewById(R.id.listView);
listView.setAdapter(adapter);
listView.setOnScrollListener(new AbsListView.OnScrollListener(){
private int lastFirstVisibleItem;
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if(lastFirstVisibleItem<firstVisibleItem){
Toast.makeText(getApplicationContext(), "Scrolling down the listView",
Toast.LENGTH_SHORT).show();
}
if(lastFirstVisibleItem>firstVisibleItem){
Toast.makeText(getApplicationContext(), "Scrolling up the listView",
Toast.LENGTH_SHORT).show();
}
lastFirstVisibleItem=firstVisibleItem;
}
});
}
}
步骤 4 − 将以下代码添加到 androidManifest.xml
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.sample"> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name=".MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
让我们尝试运行您的应用程序。假设您已将实际的 Android 移动设备连接到电脑。要从 Android Studio 运行该应用程序，请打开项目的某个活动文件，然后点击工具栏上的"运行"
图标。选择您的移动设备作为选项，然后勾选将显示默认屏幕的移动设备。 −
