ue4-HUD绘制UI(C++)

HUD绘制UI，其他绘制相关的接口看源码就可以使用了

1. 创建继承自AHUD的c++类-AMyHUD，构造函数中加载一些资源

   • MyHUD.h

     UCLASS()
     class MYQWE_API AMyHUD : public AHUD
     {
         GENERATED_UCLASS_BODY()
     
     public:
         virtual void    DrawHUD() override; //重写父类的绘制函数
     
         void            DrawMyIcons(); //绘制图片
         void            DrawMyItems(); //绘制文字
     
         UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "MyHUD")
             UTexture2D* mTexture2d;
         float       mScaleFactor;
     
         UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "MyHUD")
             FCanvasIcon mIcons1;
     
         UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "MyHUD")
             FCanvasIcon mIcons2;
     
         UTexture2D* mTextureArrowDown;
         UTexture2D* mTextureArrowLeft;
         FCanvasIcon mAllIcons[2];
     
         UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "MyHUD")
             UFont*          mFont;
     };

   • MyHUD.cpp

     
     #include "Engine/StreamableManager.h"
     
     
     AMyHUD::AMyHUD(const FObjectInitializer& ObjectInitializer) : Super(ObjectInitializer)
     {
         //加载资源方式1
         FStreamableManager* stream = new FStreamableManager();
         FStringAssetReference ref(TEXT("/Game/UI/bb"));
         mTexture2d = Cast<UTexture2D>(stream->SynchronousLoad(ref));
     
         //加载资源方式2
         static ConstructorHelpers::FObjectFinder<UTexture2D> TextureArrowDownOb(TEXT("/Game/UI/Arrow_Down_1"));
         static ConstructorHelpers::FObjectFinder<UTexture2D> TextureArrowLeftOb(TEXT("/Game/UI/Arrow_Left_2"));
     
         mTextureArrowDown = TextureArrowDownOb.Object;
         mTextureArrowLeft = TextureArrowLeftOb.Object;
     
         //四个float理解为Rect即可，只不过表示的是贴图中的uv坐标，而不是坐标系中xy坐标
         //以像素为单位，而不是uv中的范围0-1
         mAllIcons[0] = UCanvas::MakeIcon(mTextureArrowDown, 0, 0, 60, 60);
         mAllIcons[1] = UCanvas::MakeIcon(mTextureArrowLeft, 0, 0, 60, 60);
     
         mIcons1 = mAllIcons[0];
         mIcons2 = mAllIcons[1];
     
         //加载字体
         static ConstructorHelpers::FObjectFinder<UFont> FontOb(TEXT("/Game/UI/Roboto51"));
         mFont = FontOb.Object;
     
     }
     
     void AMyHUD::DrawHUD()
     {
         Super::DrawHUD();
     
         if (!Canvas)
             return;
     
         mScaleFactor = Canvas->ClipY / 1080.0f;
         DrawMyIcons();
         DrawMyItems();
     
         Canvas->DrawText(mFont, FString(TEXT("--- DrawText")), 150.f, 150.f);
     }
     
     void AMyHUD::DrawMyIcons()
     {
         const float StartX = Canvas->ClipX / 2.0f;
         const float StartY = Canvas->ClipY / 2.0f;
     
         for (size_t i = 0; i < 2; i++)
         {
             //使用Canvas绘制icon
             Canvas->DrawIcon(mAllIcons[i], StartX + 100 * i, StartY + 100 * i, mScaleFactor);
         }
     }
     
     void AMyHUD::DrawMyItems()
     {
         FCanvasTextItem textItem = FCanvasTextItem(FVector2D::ZeroVector, FText::GetEmpty(), mFont, FLinearColor::Red);
         textItem.Text = FText::FromString(TEXT("--- TextItem String!"));
         Canvas->DrawItem(textItem, 300.f, 300.f);
     }

2. 资源路径
   

3. 构造中加载直接就可以在编辑器中看到