# @correctness/v1-state-object-member-used-in-function-parameter-check

在 build() 方法内，避免将@Observed和@ObjectLink装饰的类对象的状态变量直接作为参数传递给方法（如 a.b(this.object)）。

#### 规则配置

```
// code-linter.json5
{
  "rules": {
    "@correctness/v1-state-object-member-used-in-function-parameter-check": "warn"
  }
}
```

#### 选项

该规则无需配置额外选项。

#### 正例

```
@Observed
class Weather {
  temperature:number;

  constructor(temperature:number) {
    this.temperature = temperature;
  }

  static increaseTemperature(weather:Weather) {
    weather.temperature++;
  }
}

class Day {
  weather:Weather;
  week:string;
  constructor(weather:Weather, week:string) {
    this.weather = weather;
    this.week = week;
  }
}

@Entry
@Component
struct Parent {
  @State day1: Day = new Day(new Weather(15), 'Monday');

  build() {
    Column({ space:10 }) {
      Child({ weather: this.day1.weather})
    }
    .height('100%')
    .width('100%')
  }
}

@Component
struct Child {
  @ObjectLink weather: Weather;

  reduceTemperature (weather:Weather) {
    weather.temperature--;
  }

  build() {
    Column({ space:10 }) {
      Text(`The temperature of day1 is ${this.weather.temperature} degrees.`)
        .fontSize(20)
      Button('increaseTemperature')
        .onClick(()=>{
          // 通过赋值添加 Proxy 代理
          let weather1 = this.weather;
          Weather.increaseTemperature(weather1);
        })
      Button('reduceTemperature')
        .onClick(()=>{
          // 通过赋值添加 Proxy 代理
          let weather2 = this.weather;
          this.reduceTemperature(weather2);
        })
    }
    .height('100%')
    .width('100%')
  }
}
```

#### 反例

```
@Observed
class Weather {
  temperature:number;

  constructor(temperature:number) {
    this.temperature = temperature;
  }

  static increaseTemperature(weather:Weather) {
    weather.temperature++;
  }
}

class Day {
  weather:Weather;
  week:string;
  constructor(weather:Weather, week:string) {
    this.weather = weather;
    this.week = week;
  }
}

@Entry
@Component
struct Parent {
  @State day1: Day = new Day(new Weather(15), 'Monday');

  build() {
    Column({ space:10 }) {
      Child({ weather: this.day1.weather})
    }
    .height('100%')
    .width('100%')
  }
}

@Component
struct Child {
  @ObjectLink weather: Weather;

  reduceTemperature (weather:Weather) {
    weather.temperature--;
  }

  build() {
    Column({ space:10 }) {
      Text(`The temperature of day1 is ${this.weather.temperature} degrees.`)
        .fontSize(20)
      Button('increaseTemperature')
        .onClick(()=>{
          // 通过静态方法调用，无法触发UI刷新
          Weather.increaseTemperature(this.weather);
        })
      Button('reduceTemperature')
        .onClick(()=>{
          // 使用this通过自定义组件内部方法调用，无法触发UI刷新
          this.reduceTemperature(this.weather);
        })
    }
    .height('100%')
    .width('100%')
  }
}
```

#### 规则集

```
plugin:@correctness/all
```

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