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如何将列表从一个活动传递到另一个活动?

android-manifest android-activity android-studio android java

Igal · 技术社区 · 2 年前

我是安卓工作室的新手,正在尝试开发我的第一个应用程序。

我有3个活动MainActivity、DashboardActivity和SplashActivity。

仪表板活动-

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_dashboard);

    Hooks();
    allQuestionsList=listS;
    Collections.shuffle(allQuestionsList);
    modelClass = listS.get(index);

    setAllData();

}

启动活动-

public class SplashActivity extends AppCompatActivity {
public static ArrayList<ModelClass> listS;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.splash_activity_main);

    listS = new ArrayList<>();
    listS.add(new ModelClass("here is the question", "a", "b", "c", "d", "answer"));
    listS.add(new ModelClass("Under-inflated tires increase fuel consumption. A single tire under-inflated by 56 kpa (8 psi) can increase fuel consumption by?", "25 per cent", "15 per cent", "Seven per cent", "Four per cent", "Four per cent"));
    listS.add(new ModelClass("You are not allowed to park a vehicle within _____________ of a pedestrian corridor", "9 metres", "3 metres", "30 metres", "15 metres", "15 metres"));
    listS.add(new ModelClass("What class licence permits the holder to operate a motorcycle?", "Class 4", "Class 1", "Class 6", "Class 5", "Class 6"));
    listS.add(new ModelClass("Seatbelts must be worn by all drivers and passengers:", "Only when driving in the city", "Only when carrying passengers", "All the time unless exempted by law", "Only when driving on the highway", "All the time unless exempted by law"));

    new Handler().postDelayed(new Runnable() {
        @Override
        public void run() {
            Intent intent = new Intent(SplashActivity.this, DashboardActivity.class);
            startActivity(intent);
        }
    }, 1500);
}

这是我的AndroidManifest-

<application
android:allowBackup="true"
android:dataExtractionRules="@xml/data_extraction_rules"
android:fullBackupContent="@xml/backup_rules"
android:icon="@drawable/mainscreenlogo"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/Theme.QuizTheoryApplication"
tools:targetApi="31">

<activity
    android:name=".example.QuizTheoryApplication.MainActivity"
    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=".example.QuizTheoryApplication.DashboardActivity"
    android:label="Preferences"
    android:exported="true">
    <intent-filter>
        <action android:name="com.iphonik.chameleon.AppPreferenceActivity" />
        <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>
</activity>

<activity
    android:name=".example.QuizTheoryApplication.SplashActivity"
    android:label="Preferences"
    android:exported="true">
    <intent-filter>
        <action android:name="com.iphonik.chameleon.AppPreferenceActivity" />
        <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>
</activity>

问题是我的Splash活动没有运行,当然,列表总是空的。我尝试添加Dashboard活动,但没有成功-

new Handler().postDelayed(new Runnable() 
{ @Override public void run() 
{ Intent intent = new Intent(DashboardActivity.this, SplashActivity.class); startActivity(intent); } }, 1500);

我也试着使用 intent.putStringArrayListExtra("list", listS);

和 ArrayList<String> receivedList = getIntent().getStringArrayListExtra("list")
但没有任何成功。我很乐意在这件事上提供帮助。谢谢

0 回复 | 直到 2 年前

basileus 2 年前

我不知道你的ModelClass到底是什么。但如果你能让它成为Parcelable或Serializable,那么你就可以简单地使用Bundle将数据(listS)发送到新的Activity。你应该这样做:

在里面 飞溅活跃度 :

   new Handler().postDelayed(new Runnable() {
    @Override
    public void run() {
        Intent intent = new Intent(SplashActivity.this, DashboardActivity.class);
        Bundle extras = new Bundle();
        extras.putParcelableArrayList(YOUR_KEY, listS); // or putSerializable instead if ModelClass can implement Serializable
        intent.putExtras(extras);
        startActivity(intent);
    }
   }

然后在 仪表板活动 :

protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dashboard);

if (savedInstanceState != null) {
    listS = savedInstanceState.getParcelableArrayList(YOUR_KEY); // or getSerializable instead you used putSerializable
}

Hooks();
allQuestionsList=listS;
Collections.shuffle(allQuestionsList);
modelClass = listS.get(index);

setAllData();