[2.4.1] 尝试修复 #9 问题。

src/main/java/cc/carm/plugin/userprefix/event/UserPrefixChangeEvent.java

@@ -1,12 +1,17 @@
 package cc.carm.plugin.userprefix.event;
 
+import cc.carm.plugin.userprefix.Main;
 import cc.carm.plugin.userprefix.model.ConfiguredPrefix;
+import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
+import org.bukkit.scheduler.BukkitRunnable;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.function.Consumer;
+
 public class UserPrefixChangeEvent extends UserPrefixEvent implements Cancellable {
 
 	public static HandlerList handler = new HandlerList();
@@ -52,4 +57,19 @@ public class UserPrefixChangeEvent extends UserPrefixEvent implements Cancellabl
 	public HandlerList getHandlers() {
 		return handler;
 	}
+
+	public static void call(@NotNull Player who,
+							@Nullable ConfiguredPrefix before,
+							@NotNull ConfiguredPrefix after,
+							@Nullable Consumer<@Nullable ConfiguredPrefix> finish) {
+		new BukkitRunnable() {
+			@Override
+			public void run() {
+				UserPrefixChangeEvent event = new UserPrefixChangeEvent(who, before, after);
+				Bukkit.getPluginManager().callEvent(event);
+				if (finish != null) finish.accept(event.isCancelled() ? null : event.getAfter());
+			}
+		}.runTask(Main.getInstance());
+	}
+
 }

src/main/java/cc/carm/plugin/userprefix/event/UserPrefixExpireEvent.java

@@ -1,8 +1,11 @@
 package cc.carm.plugin.userprefix.event;
 
+import cc.carm.plugin.userprefix.Main;
 import cc.carm.plugin.userprefix.model.ConfiguredPrefix;
+import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
 import org.bukkit.event.HandlerList;
+import org.bukkit.scheduler.BukkitRunnable;
 import org.jetbrains.annotations.NotNull;
 
 public class UserPrefixExpireEvent extends UserPrefixEvent {
@@ -27,4 +30,14 @@ public class UserPrefixExpireEvent extends UserPrefixEvent {
 	public HandlerList getHandlers() {
 		return handler;
 	}
+
+	public static void call(@NotNull Player player, @NotNull ConfiguredPrefix currentPrefix) {
+		new BukkitRunnable() {
+			@Override
+			public void run() {
+				Bukkit.getPluginManager().callEvent(new UserPrefixExpireEvent(player, currentPrefix));
+			}
+		}.runTask(Main.getInstance());
+	}
+
 }

src/main/java/cc/carm/plugin/userprefix/manager/UserManager.java

@@ -121,7 +121,7 @@ public class UserManager {
 
 			if (currentPrefix != null) {
 				//当前前缀不为空，则代表属于前缀过期的情况
-				Bukkit.getPluginManager().callEvent(new UserPrefixExpireEvent(player, currentPrefix));
+				UserPrefixExpireEvent.call(player, currentPrefix);
 
 				// 发送消息
 				PluginConfig.Messages.EXPIRED.sendWithPlaceholders(player,
@@ -139,17 +139,16 @@ public class UserManager {
 				);
 			}
 
-			UserPrefixChangeEvent event = new UserPrefixChangeEvent(player, currentPrefix, newPrefix);
-			Bukkit.getPluginManager().callEvent(event);
-
-			if (!event.isCancelled()) {
-				// 更新前缀
-				UserManager.setPrefix(player, event.getAfter(), updateView);
-			}
-
+			UserPrefixChangeEvent.call(player, currentPrefix, newPrefix, (after) -> {
+				if (after != null) {
+					UserManager.setPrefix(player, after, updateView);
+				}
+				checkingPlayers.remove(player.getUniqueId());
+			});
+			
+		} else {
+			checkingPlayers.remove(player.getUniqueId());
 		}
-
-		checkingPlayers.remove(player.getUniqueId());
 	}
 
 	public static void unloadNameTag(UUID uuid) {