ArkTS会对自定义组件的成员变量使用的访问限定符private/public/protected进行校验，当不按规范使用访问限定符private/public/protected时，会产生对应的日志信息。
说明：
从API version 12开始，支持自定义组件成员属性访问限定符使用限制的规则。
使用限制
对于@State/@Prop/@Provide/@BuilderParam/常规成员变量(不涉及更新的普通变量)，当使用private修饰时，在自定义组件构造时，不允许进行赋值传参，否则会有编译告警日志提示。
对于@StorageLink/@StorageProp/@LocalStorageLink/@LocalStorageLink/@Consume变量，当使用public修饰时，会有编译告警日志提示。
对于@Link/@ObjectLink变量，当使用private修饰时，会有编译告警日志提示。
由于struct没有继承能力，上述所有的这些变量使用protected修饰时，会有编译告警日志提示。
当@Require和private同时修饰自定义组件struct的@State/@Prop/@Provide/@BuilderParam/常规成员变量(不涉及更新的普通变量)时，会有编译告警日志提示。
错误使用场景示例
1.当成员变量被private访问限定符和@State/@Prop/@Provide/@BuilderParam装饰器同时修饰时，ArkTS会进行校验并产生告警日志。
@Entry
@Component
struct AccessRestrictions {
@Builder buildTest() {
Text("Parent builder")
}
build() {
Column() {
ComponentsChild({state_value: "Hello", prop_value: "Hello", provide_value: "Hello", builder_value: this.buildTest, regular_value: "Hello"})
}
.width('100%')
}
}
@Component
struct ComponentsChild {
@State private state_value: string = "Hello";
@Prop private prop_value: string = "Hello";
@Provide private provide_value: string = "Hello";
@BuilderParam private builder_value: () => void = this.buildTest;
private regular_value: string = "Hello";
@Builder buildTest() {
Text("Child builder")
}
build() {
Column() {
Text("Hello")
.fontSize(50)
.fontWeight(FontWeight.Bold)
}
}
}
编译告警日志如下：
Property 'state_value' is private and can not be initialized through the component constructor.
Property 'prop_value' is private and can not be initialized through the component constructor.
Property 'provide_value' is private and can not be initialized through the component constructor.
Property 'builder_value' is private and can not be initialized through the component constructor.
Property 'regular_value' is private and can not be initialized through the component constructor.
2.当成员变量被public访问限定符和@StorageLink/@StorageProp/@LocalStorageLink/@LocalStorageLink/@Consume装饰器同时修饰时，ArkTS会进行校验并产生告警日志。
@Entry
@Component
struct AccessRestrictions {
@Provide consume_value: string = "Hello";
build() {
Column() {
ComponentChild()
}
.width('100%')
}
}
@Component
struct ComponentChild {
@LocalStorageProp("sessionLocalProp") public local_prop_value: string = "Hello";
@LocalStorageLink("sessionLocalLink") public local_link_value: string = "Hello";
@StorageProp("sessionProp") public storage_prop_value: string = "Hello";
@StorageLink("sessionLink") public storage_link_value: string = "Hello";
@Consume public consume_value: string;
build() {
Column() {
Text("Hello")
.fontSize(50)
.fontWeight(FontWeight.Bold)
}
}
}
编译告警日志如下：
Property 'local_prop_value' can not be decorated with both @LocalStorageProp and public.
Property 'local_link_value' can not be decorated with both @LocalStorageLink and public.
Property 'storage_prop_value' can not be decorated with both @StorageProp and public.
Property 'storage_link_value' can not be decorated with both @StorageLink and public.
Property 'consume_value' can not be decorated with both @Consume and public.
3.当成员变量被private访问限定符和@Link/@ObjectLink装饰器同时修饰时，ArkTS会进行校验并产生告警日志。
@Entry
@Component
struct AccessRestrictions {
@State link_value: string = "Hello";
@State objectLink_value: ComponentObj = new ComponentObj();
build() {
Column() {
ComponentChild({link_value: this.link_value, objectLink_value: this.objectLink_value})
}
.width('100%')
}
}
@Observed
class ComponentObj {
count: number = 0;
}
@Component
struct ComponentChild {
@Link private link_value: string;
@ObjectLink private objectLink_value: ComponentObj;
build() {
Column() {
Text("Hello")
.fontSize(50)
.fontWeight(FontWeight.Bold)
}
}
}
编译告警日志如下：
Property 'link_value' can not be decorated with both @Link and private.
Property 'objectLink_value' can not be decorated with both @ObjectLink and private.
4.当成员变量被protected访问限定符修饰时，ArkTS会进行校验并产生告警日志。
@Entry
@Component
struct AccessRestrictions {
build() {
Column() {
ComponentChild({regular_value: "Hello"})
}
.width('100%')
}
}
@Component
struct ComponentChild {
protected regular_value: string = "Hello";
build() {
Column() {
Text("Hello")
.fontSize(50)
.fontWeight(FontWeight.Bold)
}
}
}
编译告警日志如下：
The member attributes of a struct can not be protected.
5.当成员变量被private访问限定符、@Require和@State/@Prop/@Provide/@BuilderParam装饰器同时修饰时，ArkTS会进行校验并产生告警日志。
@Entry
@Component
struct AccessRestrictions {
build() {
Column() {
ComponentChild({prop_value: "Hello"})
}
.width('100%')
}
}
@Component
struct ComponentChild {
@Require @Prop private prop_value: string = "Hello";
build() {
Column() {
Text("Hello")
.fontSize(50)
.fontWeight(FontWeight.Bold)
}
}
}
编译告警日志如下：
Property 'prop_value' can not be decorated with both @Require and private.
Property 'prop_value' is private and can not be initialized through the component constructor.
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