寫一個 Android 版本的抽象工廠彈窗 + Manager 管理器，使用 DialogFragment 實現，這樣能更貼近真實的開發場景。

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結構設計

1. 抽象產品：BaseDialogFragment（繼承 DialogFragment）
2. 具體產品：LoginDialogFragment, UpdateDialogFragment
3. 抽象工廠：DialogFactory
4. 具體工廠：LoginDialogFactory, UpdateDialogFactory
5. 彈窗管理器：DialogManager（統一展示 / 關閉彈窗）

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代碼實現

抽象產品

import android.app.Dialog;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.DialogFragment;public abstract class BaseDialogFragment extends DialogFragment {@NonNull@Overridepublic abstract Dialog onCreateDialog(@Nullable Bundle savedInstanceState);public void dismissDialog() {if (getDialog() != null && getDialog().isShowing()) {dismiss();}}
}

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具體產品

import android.app.AlertDialog;
import android.app.Dialog;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;public class LoginDialogFragment extends BaseDialogFragment {@NonNull@Overridepublic Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {return new AlertDialog.Builder(requireContext()).setTitle("登錄").setMessage("請輸入賬號密碼").setPositiveButton("確定", (dialog, which) -> {// 登錄邏輯}).setNegativeButton("取消", null).create();}
}

import android.app.AlertDialog;
import android.app.Dialog;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;public class UpdateDialogFragment extends BaseDialogFragment {@NonNull@Overridepublic Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {return new AlertDialog.Builder(requireContext()).setTitle("更新提示").setMessage("檢測到新版本，是否更新？").setPositiveButton("更新", (dialog, which) -> {// 更新邏輯}).setNegativeButton("稍后", null).create();}
}

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抽象工廠

public interface DialogFactory {BaseDialogFragment createDialog();
}

具體工廠

public class LoginDialogFactory implements DialogFactory {@Overridepublic BaseDialogFragment createDialog() {return new LoginDialogFragment();}
}

public class UpdateDialogFactory implements DialogFactory {@Overridepublic BaseDialogFragment createDialog() {return new UpdateDialogFragment();}
}

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彈窗管理器

import androidx.fragment.app.FragmentManager;
import java.util.HashMap;
import java.util.Map;public class DialogManager {private static final Map<String, BaseDialogFragment> dialogCache = new HashMap<>();public static void showDialog(String key, DialogFactory factory, FragmentManager fragmentManager) {if (!dialogCache.containsKey(key)) {dialogCache.put(key, factory.createDialog());}BaseDialogFragment dialog = dialogCache.get(key);if (dialog != null && !dialog.isAdded()) {dialog.show(fragmentManager, key);}}public static void dismissDialog(String key) {BaseDialogFragment dialog = dialogCache.get(key);if (dialog != null) {dialog.dismissDialog();dialogCache.remove(key);}}
}

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使用示例 (Activity 中調用)

public class MainActivity extends AppCompatActivity {@Overrideprotected void onResume() {super.onResume();// 顯示登錄彈窗DialogManager.showDialog("login", new LoginDialogFactory(), getSupportFragmentManager());// 顯示更新彈窗DialogManager.showDialog("update", new UpdateDialogFactory(), getSupportFragmentManager());// 關閉登錄彈窗DialogManager.dismissDialog("login");}
}

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? 優點：

• 擴展性強：新增一個彈窗，只需要新增 DialogFragment + Factory，DialogManager 無需改動
• 全局管理：可以統一控制彈窗的緩存、復用、顯示/關閉邏輯
• 線程安全：使用 FragmentManager 管理生命周期，避免內存泄漏

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再加一個 全局策略（比如保證同一時間只顯示一個彈窗，后來的會自動關閉之前的）

在 DialogManager 里加一個 全局策略：同一時間只允許顯示一個彈窗。這樣新的彈窗顯示時，會自動關閉之前的。

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改造后的 DialogManager

import androidx.fragment.app.FragmentManager;
import java.util.HashMap;
import java.util.Map;public class DialogManager {private static final Map<String, BaseDialogFragment> dialogCache = new HashMap<>();private static String currentDialogKey = null; // 當前正在顯示的彈窗 keypublic static void showDialog(String key, DialogFactory factory, FragmentManager fragmentManager) {// 如果有正在顯示的彈窗，先關閉if (currentDialogKey != null && dialogCache.containsKey(currentDialogKey)) {dismissDialog(currentDialogKey);}// 創建或獲取彈窗if (!dialogCache.containsKey(key)) {dialogCache.put(key, factory.createDialog());}BaseDialogFragment dialog = dialogCache.get(key);// 顯示彈窗if (dialog != null && !dialog.isAdded()) {dialog.show(fragmentManager, key);currentDialogKey = key;}}public static void dismissDialog(String key) {BaseDialogFragment dialog = dialogCache.get(key);if (dialog != null) {dialog.dismissDialog();dialogCache.remove(key);if (key.equals(currentDialogKey)) {currentDialogKey = null;}}}public static void dismissCurrentDialog() {if (currentDialogKey != null) {dismissDialog(currentDialogKey);}}public static boolean isDialogShowing() {return currentDialogKey != null;}
}

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使用示例

public class MainActivity extends AppCompatActivity {@Overrideprotected void onResume() {super.onResume();// 顯示登錄彈窗DialogManager.showDialog("login", new LoginDialogFactory(), getSupportFragmentManager());// 這里再顯示更新彈窗時，會自動關閉上一個（login）DialogManager.showDialog("update", new UpdateDialogFactory(), getSupportFragmentManager());// 關閉當前正在顯示的彈窗（update）DialogManager.dismissCurrentDialog();}
}

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? 這樣就具備了：

1. 抽象工廠擴展性：新增彈窗不用改管理器。
2. 緩存 & 復用：避免重復創建相同彈窗。
3. 全局策略：同一時間只顯示一個彈窗。
4. 可選擴展：還能加優先級隊列（比如：強制更新彈窗 > 登錄彈窗 > 普通提示彈窗）。

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