vault backup: 2024-10-12 17:19:45

03-UnrealEngine/Gameplay/UObject/UnrealSpecifiers/Specifier/UFUNCTION/Network/WithValidation.md

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+# WithValidation
+
+- **功能描述：** 指定一个RPC函数在执行前需要验证，只有验证通过才可以执行。
+- **元数据类型：** bool
+- **引擎模块：** Network
+- **作用机制：** 在FunctionFlags中加入[FUNC_NetValidate](../../../Flags/EFunctionFlags/FUNC_NetValidate.md)
+- **常用程度：★★★★★**
+
+指定一个RPC函数在执行前需要验证，只有验证通过才可以执行。
+
+WithValidation实际上可以用于Client，Server，NetMulticast的RPC函数，但一般来说还是用在Server的最多，因为一般是Server的数据最权威可以进行数据合法性校验。
+
+## 测试代码：
+
+```cpp
+UCLASS(Blueprintable, BlueprintType)
+class INSIDER_API AMyFunction_PlayerController :public APlayerController
+{
+	GENERATED_BODY()
+public:
+	UFUNCTION(BlueprintCallable, Client, Reliable,WithValidation)
+	void MyFunc2_RunOnClient();
+
+		UFUNCTION(BlueprintCallable, Server, Reliable,WithValidation)
+	void MyFunc2_RunOnServer();
+};
+
+UCLASS(Blueprintable, BlueprintType)
+class INSIDER_API AMyFunction_Network :public AActor
+{
+public:
+	GENERATED_BODY()
+	UFUNCTION(BlueprintCallable, NetMulticast, Reliable,WithValidation)
+	void MyFunc2_NetMulticast();
+};
+
+void AMyFunction_PlayerController::MyFunc2_RunOnServer_Implementation()
+{
+	UInsiderLibrary::PrintFuncStatus(this, TEXT("MyFunc2_RunOnServer_Implementation"));
+}
+
+bool AMyFunction_PlayerController::MyFunc2_RunOnServer_Validate()
+{
+	UInsiderLibrary::PrintFuncStatus(this, TEXT("MyFunc2_RunOnServer_Validate"));
+	return true;
+}
+
+bool AMyFunction_Network::MyFunc2_NetMulticast_Validate()
+{
+	UInsiderLibrary::PrintFuncStatus(this, TEXT("MyFunc2_NetMulticast_Validate"));
+	return true;
+}
+```
+
+## 测试结果：
+
+```cpp
+RunOnClient:
+LogInsider: Display: 815f7800    MyFunc2_RunOnClient_Validate    BP_NetworkPC_C_0    NM_Client   Local:ROLE_AutonomousProxy  Remote:ROLE_Authority
+LogInsider: Display: 815f7800    MyFunc2_RunOnClient_Implementation  BP_NetworkPC_C_0    NM_Client   Local:ROLE_AutonomousProxy  Remote:ROLE_Authority
+
+RunOnServer:
+LogInsider: Display: 7fd11800    MyFunc2_RunOnServer_Validate    BP_NetworkPC_C_1    NM_ListenServer Local:ROLE_Authority    Remote:ROLE_AutonomousProxy
+LogInsider: Display: 7fd11800    MyFunc2_RunOnServer_Implementation  BP_NetworkPC_C_1    NM_ListenServer Local:ROLE_Authority    Remote:ROLE_AutonomousProxy
+
+Multicast: ServerOwned
+LogInsider: Display: 947e6400    MyFunc2_NetMulticast_Validate   BP_Network_C_1  NM_ListenServer Local:ROLE_Authority    Remote:ROLE_SimulatedProxy
+LogInsider: Display: 947e6400    MyFunc2_NetMulticast_Implementation BP_Network_C_1  NM_ListenServer Local:ROLE_Authority    Remote:ROLE_SimulatedProxy
+LogInsider: Display: 8795eb00    MyFunc2_NetMulticast_Validate   BP_Network_C_1  NM_Client   Local:ROLE_SimulatedProxy   Remote:ROLE_Authority
+LogInsider: Display: 8795eb00    MyFunc2_NetMulticast_Implementation BP_Network_C_1  NM_Client   Local:ROLE_SimulatedProxy   Remote:ROLE_Authority
+LogInsider: Display: 8f6a3700    MyFunc2_NetMulticast_Validate   BP_Network_C_1  NM_Client   Local:ROLE_SimulatedProxy   Remote:ROLE_Authority
+LogInsider: Display: 8f6a3700    MyFunc2_NetMulticast_Implementation BP_Network_C_1  NM_Client   Local:ROLE_SimulatedProxy   Remote:ROLE_Authority
+
+```
+
+## 原理：
+
+如果加上WithValidation标记，在UHT生成代码的时候就会：
+
+```cpp
+DEFINE_FUNCTION(AMyFunction_PlayerController::execMyFunc2_RunOnServer)
+	{
+		P_FINISH;
+		P_NATIVE_BEGIN;
+		if (!P_THIS->MyFunc2_RunOnServer_Validate())
+		{
+			RPC_ValidateFailed(TEXT("MyFunc2_RunOnServer_Validate"));
+			return;
+		}
+		P_THIS->MyFunc2_RunOnServer_Implementation();
+		P_NATIVE_END;
+	}
+	DEFINE_FUNCTION(AMyFunction_PlayerController::execMyFunc2_RunOnClient)
+	{
+		P_FINISH;
+		P_NATIVE_BEGIN;
+		if (!P_THIS->MyFunc2_RunOnClient_Validate())
+		{
+			RPC_ValidateFailed(TEXT("MyFunc2_RunOnClient_Validate"));
+			return;
+		}
+		P_THIS->MyFunc2_RunOnClient_Implementation();
+		P_NATIVE_END;
+	}
+
+DEFINE_FUNCTION(AMyFunction_Network::execMyFunc2_NetMulticast)
+{
+	P_FINISH;
+	P_NATIVE_BEGIN;
+	if (!P_THIS->MyFunc2_NetMulticast_Validate())
+	{
+		RPC_ValidateFailed(TEXT("MyFunc2_NetMulticast_Validate"));
+		return;
+	}
+	P_THIS->MyFunc2_NetMulticast_Implementation();
+	P_NATIVE_END;
+}
+```