1、定义

  	UPROPERTY(Category = Block, VisibleDefaultsOnly, BlueprintReadOnly, meta = (AllowPrivateAccess = "true"))
	class UStaticMeshComponent* BlockMesh;
	/** Pointer to white material used on the focused block */
	UPROPERTY()
	class UMaterial* BaseMaterial;

	/** Pointer to blue material used on inactive blocks */
	UPROPERTY()
	class UMaterialInstance* BlueMaterial;

	/** Pointer to orange material used on active blocks */
	UPROPERTY()
	class UMaterialInstance* OrangeMaterial;

2、赋值

	// Structure to hold one-time initialization
	struct FConstructorStatics
	{
    
    
		ConstructorHelpers::FObjectFinderOptional<UStaticMesh> PlaneMesh;
		ConstructorHelpers::FObjectFinderOptional<UMaterial> BaseMaterial;
		ConstructorHelpers::FObjectFinderOptional<UMaterialInstance> BlueMaterial;
		ConstructorHelpers::FObjectFinderOptional<UMaterialInstance> OrangeMaterial;
		FConstructorStatics()
			: PlaneMesh(TEXT("/Game/Puzzle/Meshes/PuzzleCube.PuzzleCube"))
			, BaseMaterial(TEXT("/Game/Puzzle/Meshes/BaseMaterial.BaseMaterial"))
			, BlueMaterial(TEXT("/Game/Puzzle/Meshes/BlueMaterial.BlueMaterial"))
			, OrangeMaterial(TEXT("/Game/Puzzle/Meshes/OrangeMaterial.OrangeMaterial"))
		{
    
    
		}
	};
	static FConstructorStatics ConstructorStatics;


	// Create static mesh component
	BlockMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("BlockMesh0"));
	BlockMesh->SetStaticMesh(ConstructorStatics.PlaneMesh.Get());
	BlockMesh->SetRelativeScale3D(FVector(1.f,1.f,0.25f));
	BlockMesh->SetRelativeLocation(FVector(0.f,0.f,25.f));
	BlockMesh->SetMaterial(0, ConstructorStatics.BlueMaterial.Get());
	BlockMesh->SetupAttachment(DummyRoot);
	BlockMesh->OnClicked.AddDynamic(this, &APuzzleBlock::BlockClicked);
	BlockMesh->OnInputTouchBegin.AddDynamic(this, &APuzzleBlock::OnFingerPressedBlock);

	// Save a pointer to the orange material
	BaseMaterial = ConstructorStatics.BaseMaterial.Get();
	BlueMaterial = ConstructorStatics.BlueMaterial.Get();
	OrangeMaterial = ConstructorStatics.OrangeMaterial.Get();

**BlockMesh->SetMaterial(0, BaseMaterial);**