- Create a new Actor class called BlueprintPropertyActor using the editor wizard:<\/li><\/ol>\n\n\n\n
![\"\"\/](\"http:\/\/blog.coolcoding.cn\/wp-content\/uploads\/2021\/01\/40067092-2b56-401c-8825-8bfea89f5019.png\")
<\/figure>\n\n\n\n- Add the following UPROPERTY to the class using Visual Studio:<\/li><\/ol>\n\n\n\n
#pragma once
#include \"CoreMinimal.h\"
#include \"GameFramework\/Actor.h\"
#include \"BlueprintPropertyActor.generated.h\"
UCLASS()
class CHAPTER_09_API ABlueprintPropertyActor : public AActor
{
GENERATED_BODY()
public:
\/\/ Sets default values for this actor's properties
ABlueprintPropertyActor();
protected:
\/\/ Called when the game starts or when spawned
virtual void BeginPlay() override;
public:
\/\/ Called every frame
virtual void Tick(float DeltaTime) override;
UPROPERTY(BlueprintReadWrite, Category = Cookbook)<\/strong>
bool ReadWriteProperty;<\/strong>
UPROPERTY(BlueprintReadOnly, Category = Cookbook)<\/strong>
bool ReadOnlyProperty;<\/strong>
};<\/pre>\n\n\n\n- Perform a Save, Compile your project, and start the editor.<\/li>
- Create a Blueprint class based on your BlueprintPropertyActor and open its graph.<\/li>
- From the My Blueprint panel, click on the eye icon to the right of the Search bar. From there, select Show Inherited Variables:<\/li><\/ol>\n\n\n\n
![\"\"\/](\"http:\/\/blog.coolcoding.cn\/wp-content\/uploads\/2021\/01\/04be7b53-3abc-4b96-91df-41feeef6a5b6.png\")
<\/figure>\n\n\n\n- Verify that the properties are visible under the Cookbook category in the Variables section of the My Blueprint panel:<\/li><\/ol>\n\n\n\n
![\"\"\/](\"http:\/\/blog.coolcoding.cn\/wp-content\/uploads\/2021\/01\/bba20056-25a1-4ae7-90cf-639c18d06265.jpg\")
<\/figure>\n\n\n\n- Left-click and drag the ReadWriteProperty variable into the Event Graph. Then select Get ReadWriteProperty:<\/li><\/ol>\n\n\n\n
![\"\"\/](\"http:\/\/blog.coolcoding.cn\/wp-content\/uploads\/2021\/01\/5ba2bbaf-baa3-48ca-ab9c-c7c14d66d450.png\")
<\/figure>\n\n\n\n- Repeat the previous step, but instead select Set ReadWriteProperty.<\/li>
- Drag the ReadOnly property into the graph and note that the SET node is disabled:<\/li><\/ol>\n\n\n\n
![\"\"\/](\"https:\/\/learning.oreilly.com\/library\/view\/unreal-engine-4x\/9781789809503\/assets\/b43adb75-6bdf-41e5-b6ec-2d103fb65f05.png\")
<\/figure>\n\n\n\nHow it works…<\/h1>\n\n\n\n
BlueprintReadWrite as a UPROPERTY specifier indicates to the Unreal Header Tool that the property should have both Get and Set operations exposed for use in Blueprints.<\/p>\n\n\n\n
BlueprintReadOnly is, as the name implies, a specifier that only allows Blueprint to retrieve the value of the property; never set it.<\/p>\n\n\n\n
BlueprintReadOnly can be useful when a property is set by native code, but should be accessible within Blueprint.<\/p>\n\n\n\n
It should be noted that\u00a0BlueprintReadWrite\u00a0and\u00a0BlueprintReadOnly\u00a0don’t specify anything about the property being accessible in the\u00a0Details\u00a0panels or the\u00a0My Blueprint\u00a0section of the editor:\u00a0these specifiers only control the generation of the getter\/setter nodes for use in Blueprint graphs.<\/p>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
The specifiers we mentioned in the previous recipe are […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[27,1],"tags":[26],"_links":{"self":[{"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=\/wp\/v2\/posts\/3062"}],"collection":[{"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3062"}],"version-history":[{"count":2,"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=\/wp\/v2\/posts\/3062\/revisions"}],"predecessor-version":[{"id":3350,"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=\/wp\/v2\/posts\/3062\/revisions\/3350"}],"wp:attachment":[{"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3062"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3062"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3062"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
- Left-click and drag the ReadWriteProperty variable into the Event Graph. Then select Get ReadWriteProperty:<\/li><\/ol>\n\n\n\n
- Verify that the properties are visible under the Cookbook category in the Variables section of the My Blueprint panel:<\/li><\/ol>\n\n\n\n
- Add the following UPROPERTY to the class using Visual Studio:<\/li><\/ol>\n\n\n\n