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03-UnrealEngine/Gameplay/GAS/GAS Ability输入绑定.md

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+---
+title: Untitled
+date: 2024-01-29 13:23:24
+excerpt: 
+tags: 
+rating: ⭐
+---
+# 前言
+相关函数主要为：
+- AbilitySystemComponent->BindToInputComponent()：只绑定名称为AbilityConfirm与AbilityCancel的InputAction。
+- AbilitySystemComponent->BindAbilityActivationToInputComponent()：输入InputComponent、FGameplayAbilityInputBinds、FTopLevelAssetPath（枚举类路径）、枚举ID，之后绑定GA与Input。
+- AbilitySystemComponent->SetBlockAbilityBindingsArray()：设置Block列表。
+
+# GAS
+BindAbilityActivationToInputComponent()的绑定方式如果ASC在Character中，可以在SetupPlayerInputComponent()中进行绑定：
+```c
+// Bind to AbilitySystemComponent
+FTopLevelAssetPath AbilityEnumAssetPath = FTopLevelAssetPath(FName("/Script/GASDocumentation"), FName("EGDAbilityInputID"));
+AbilitySystemComponent->BindAbilityActivationToInputComponent(PlayerInputComponent, FGameplayAbilityInputBinds(FString("ConfirmTarget"),
+	FString("CancelTarget"), AbilityEnumAssetPath, static_cast<int32>(EGDAbilityInputID::Confirm), static_cast<int32>(EGDAbilityInputID::Cancel)));
+```
+
+其内部主要是类似这样的方式进行绑定：
+```c++
+// Pressed event  
+{  
+    FInputActionBinding AB(FName(*FullStr), IE_Pressed);  
+    AB.ActionDelegate.GetDelegateForManualSet().BindUObject(this, &UAbilitySystemComponent::AbilityLocalInputPressed, idx);  
+    InputComponent->AddActionBinding(AB);  
+}  
+  
+// Released event  
+{  
+    FInputActionBinding AB(FName(*FullStr), IE_Released);  
+    AB.ActionDelegate.GetDelegateForManualSet().BindUObject(this, &UAbilitySystemComponent::AbilityLocalInputReleased, idx);  
+    InputComponent->AddActionBinding(AB);  
+}
+```
+
+AbilityLocalInputPressed()与AbilityLocalInputReleased()会执行：
+1. 触发多播委托
+2. TryActivateAbility() 或者 AbilitySpecInputPressed()。
+
+感觉可以自己实现一个BindAbilityActivationToInputComponent()的绑定逻辑，ASC自带的逻辑有点2。
+GAS使用的是**InputComponent->AddActionBinding**，而增强输入使用**PlayerEnhancedInputComponent->BindAction**。本质是一样的。
+```c++
+FInputActionBinding& BindAction( const FName ActionName, const EInputEvent KeyEvent, UserClass* Object, typename FInputActionHandlerSignature::TMethodPtr< UserClass > Func )  
+{  
+    FInputActionBinding AB( ActionName, KeyEvent );  
+    AB.ActionDelegate.BindDelegate(Object, Func);  
+    return AddActionBinding(MoveTemp(AB));  
+}
+```
+
+## 绑定输入而不激活能力
+如果您不希望`GameplayAbilities`在按下输入时自动激活，但仍将它们绑定到输入以与 一起使用`AbilityTasks`，则可以向您的`UGameplayAbility`子类添加一个新的 bool 变量`bActivateOnInput`，该变量默认为`true`并覆盖`UAbilitySystemComponent::AbilityLocalInputPressed()`。
+```c
+void UGSAbilitySystemComponent::AbilityLocalInputPressed(int32 InputID)
+{
+	// Consume the input if this InputID is overloaded with GenericConfirm/Cancel and the GenericConfim/Cancel callback is bound
+	if (IsGenericConfirmInputBound(InputID))
+	{
+		LocalInputConfirm();
+		return;
+	}
+
+	if (IsGenericCancelInputBound(InputID))
+	{
+		LocalInputCancel();
+		return;
+	}
+
+	// ---------------------------------------------------------
+
+	ABILITYLIST_SCOPE_LOCK();
+	for (FGameplayAbilitySpec& Spec : ActivatableAbilities.Items)
+	{
+		if (Spec.InputID == InputID)
+		{
+			if (Spec.Ability)
+			{
+				Spec.InputPressed = true;
+				if (Spec.IsActive())
+				{
+					if (Spec.Ability->bReplicateInputDirectly && IsOwnerActorAuthoritative() == false)
+					{
+						ServerSetInputPressed(Spec.Handle);
+					}
+
+					AbilitySpecInputPressed(Spec);
+
+					// Invoke the InputPressed event. This is not replicated here. If someone is listening, they may replicate the InputPressed event to the server.
+					InvokeReplicatedEvent(EAbilityGenericReplicatedEvent::InputPressed, Spec.Handle, Spec.ActivationInfo.GetActivationPredictionKey());
+				}
+				else
+				{
+					UGSGameplayAbility* GA = Cast<UGSGameplayAbility>(Spec.Ability);
+					if (GA && GA->bActivateOnInput)
+					{
+						// Ability is not active, so try to activate it
+						TryActivateAbility(Spec.Handle);
+					}
+				}
+			}
+		}
+	}
+}
+```
+
+# SDHGame
+李兄是在状态机每个节点的StateBegin()中调用CreateDynamicSkillInputActionMappingContext()进行动态绑定的。