# @performance/state-variable-usage-in-ui-format-check

建议删除不使用的UI变量。

#### 规则配置

```
// code-linter.json5
{
  "rules": {
    "@performance/state-variable-usage-in-ui-format-check": "warn",
  }
}
```

#### 选项

该规则无需配置额外选项。

#### 正例

```
class User {
  private name: string;
  constructor(name: string) {
    this.name = name;
  }
}

@Entry({ storage: new LocalStorage() })
@Component
struct Parent {
  @Prop  prop: number = 1;
  @State state: string = '1';
  @State state1: User = new User('name');
  @StorageLink(`k1`) storageLink: number = 1;
  @StorageProp(`k1`) storageProp: number = 1;
  @LocalStorageLink(`k1`) localStorageLink: number = 1;
  @LocalStorageProp(`k1`) localStorageProp: number = 1;
  @Provide('k1') provide: string = "hell";
  build() {
    Column() {
      Button() {
        Text('Insert a new item after item 1').fontSize(30)
      }

      Text(`${this.prop}`)
      Text(`${this.state}`)
      Text(`${this.state1}`)
      Text(`${this.storageLink}`)
      Text(`${this.storageProp}`)
      Text(`${this.localStorageLink}`)
      Text(`${this.localStorageProp}`)
      Text(`${this.provide}`)
    }
    .justifyContent(FlexAlign.Center)
    .width('100%')
    .height('100%')
    .backgroundColor(0xF1F3F5)
  }
}
```

#### 反例

```
class User {
  private name: string;
  constructor(name: string) {
    this.name = name;
  }
}

@Entry({ storage: new LocalStorage() })
@Component
struct Parent {
  @Prop  prop: number = 1;
  @State state: string = '1';
  @State state1: User = new User('name');
  @StorageLink(`k1`) storageLink: number = 1;
  @StorageProp(`k1`) storageProp: number = 1;
  @LocalStorageLink(`k1`) localStorageLink: number = 1;
  @LocalStorageProp(`k1`) localStorageProp: number = 1;
  @Provide('k1') provide: string = "hell";
  build() {
    Column() {
      Button() {
        Text('Insert a new item after item 1').fontSize(30)
      }

      Text(`${this.prop}`)
      Text(`${this.state}`)
    }
    .justifyContent(FlexAlign.Center)
    .width('100%')
    .height('100%')
    .backgroundColor(0xF1F3F5)
  }
}
```

#### 规则集

```
plugin:@performance/all
```

Code Linter代码检查规则的配置指导请参考Code Linter代码检查。