【Android】【设计模式】抽象工厂模式改造弹窗组件必知必会

写一个 Android 版本的抽象工厂弹窗 + Manager 管理器，使用 DialogFragment 实现，这样能更贴近真实的开发场景。

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结构设计

1. 抽象产品：BaseDialogFragment（继承 DialogFragment）
2. 具体产品：LoginDialogFragment, UpdateDialogFragment
3. 抽象工厂：DialogFactory
4. 具体工厂：LoginDialogFactory, UpdateDialogFactory
5. 弹窗管理器：DialogManager（统一展示 / 关闭弹窗）

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代码实现

抽象产品

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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具体产品

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("登录").setMessage("请输入账号密码").setPositiveButton("确定", (dialog, which) -> {// 登录逻辑}).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("检测到新版本，是否更新？").setPositiveButton("更新", (dialog, which) -> {// 更新逻辑}).setNegativeButton("稍后", null).create();}
}

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抽象工厂

public interface DialogFactory {BaseDialogFragment createDialog();
}

具体工厂

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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弹窗管理器

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 中调用)

public class MainActivity extends AppCompatActivity {@Overrideprotected void onResume() {super.onResume();// 显示登录弹窗DialogManager.showDialog("login", new LoginDialogFactory(), getSupportFragmentManager());// 显示更新弹窗DialogManager.showDialog("update", new UpdateDialogFactory(), getSupportFragmentManager());// 关闭登录弹窗DialogManager.dismissDialog("login");}
}

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✅ 优点：

• 扩展性强：新增一个弹窗，只需要新增 DialogFragment + Factory，DialogManager 无需改动
• 全局管理：可以统一控制弹窗的缓存、复用、显示/关闭逻辑
• 线程安全：使用 FragmentManager 管理生命周期，避免内存泄漏

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再加一个 全局策略（比如保证同一时间只显示一个弹窗，后来的会自动关闭之前的）

在 DialogManager 里加一个 全局策略：同一时间只允许显示一个弹窗。这样新的弹窗显示时，会自动关闭之前的。

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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; // 当前正在显示的弹窗 keypublic static void showDialog(String key, DialogFactory factory, FragmentManager fragmentManager) {// 如果有正在显示的弹窗，先关闭if (currentDialogKey != null && dialogCache.containsKey(currentDialogKey)) {dismissDialog(currentDialogKey);}// 创建或获取弹窗if (!dialogCache.containsKey(key)) {dialogCache.put(key, factory.createDialog());}BaseDialogFragment dialog = dialogCache.get(key);// 显示弹窗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();// 显示登录弹窗DialogManager.showDialog("login", new LoginDialogFactory(), getSupportFragmentManager());// 这里再显示更新弹窗时，会自动关闭上一个（login）DialogManager.showDialog("update", new UpdateDialogFactory(), getSupportFragmentManager());// 关闭当前正在显示的弹窗（update）DialogManager.dismissCurrentDialog();}
}

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✅ 这样就具备了：

1. 抽象工厂扩展性：新增弹窗不用改管理器。
2. 缓存 & 复用：避免重复创建相同弹窗。
3. 全局策略：同一时间只显示一个弹窗。
4. 可选扩展：还能加优先级队列（比如：强制更新弹窗 > 登录弹窗 > 普通提示弹窗）。

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