对《分享一下自己用c++写的小地图》一文的补充

在写完上一篇文章后，发现了一个问题：

那就是编写的插件无法实时预览。

在学习了Slate之后，我找到了方法：

重写SynchronizeProperties函数

头文件中添加:

#if WITH_EDITOR

    UFUNCTION()

    virtual void SynchronizeProperties() override;

#endif

因为只需要在编辑器中运行，所以加上了#if WITH_EDITOR

cpp文件中添加：

#if WITH_EDITOR

void UMiniMap::SynchronizeProperties()

{

    Super::SynchronizeProperties();

    WidgetSize = ;

    MapTextureSize = ;

    //构建组件

    MainMap = NewObject<UImage>(this, TEXT("MainMap"));

    PlayerCursor = NewObject<UImage>(this, TEXT("PlayerCursor"));

    Frame = NewObject<UImage>(this, TEXT("Frame"));

    //往Widget容器中加入组件

    RootPanel = Cast<UCanvasPanel>(WidgetTree->RootWidget);

    if (RootPanel)

    {

        RootPanel->AddChild(MainMap);

        RootPanel->AddChild(PlayerCursor);

        RootPanel->AddChild(Frame);

    }

    UMaterialInstance *MainMapMaterialInstance = LoadObject<UMaterialInstance>(NULL, TEXT("/Game/UI/Images/MiniMapMaterial_Instance"), NULL, LOAD_None, NULL);

    if (MainMapMaterialInstance)

    {

        MainMapMaterial = UKismetMaterialLibrary::CreateDynamicMaterialInstance(GetWorld(), MainMapMaterialInstance);

        if (MainMapMaterial->Parent->GetMaterial()->MaterialDomain == MD_UI)

        {

            UWidgetLayoutLibrary::SlotAsCanvasSlot(MainMap)->SetSize(FVector2D(WidgetSize, WidgetSize));

            MainMap->SetBrushFromMaterial(MainMapMaterial);

            MainMapMaterial->SetScalarParameterValue(FName(TEXT("MiniMapScaleRatio")), (float)WidgetSize / MapTextureSize);

        }

    }

    UTexture2D* PlayerCursorTexture = LoadObject<UTexture2D>(NULL, TEXT("/Game/UI/Images/PlayerCursor"), NULL, LOAD_None, NULL);

    if (PlayerCursorTexture)

    {

        UWidgetLayoutLibrary::SlotAsCanvasSlot(PlayerCursor)->SetSize(FVector2D(PlayerCursorTexture->GetSizeX(), PlayerCursorTexture->GetSizeY()));

        PlayerCursorSize = PlayerCursorTexture->GetSizeX();

        UWidgetLayoutLibrary::SlotAsCanvasSlot(PlayerCursor)->SetPosition(FVector2D(-PlayerCursorSize /  + WidgetSize / , -PlayerCursorSize /  + WidgetSize / ));

        PlayerCursor->SetBrushFromTexture(PlayerCursorTexture);

    }

    if (SetImageBurshFromMaterial(TEXT("/Game/UI/Images/FrameMaterial"), Frame, FVector2D(WidgetSize, WidgetSize)))

    {

        UWidgetLayoutLibrary::SlotAsCanvasSlot(Frame)->SetSize(FVector2D(WidgetSize, WidgetSize));

    }

    //后面可以考虑加入别的按钮以及边框

}

#endif

不过这样还有有一点小问题，在新建的蓝图（继承这个类的蓝图）中狂点，引擎会直接崩掉，目前找不到解决方案，引擎里都是用Slate的，论坛和AnswerHUB也都没有相关资料，不过这个问题不影响使用，所以教程到此为止了。