export default class CoursePage extends Component {
	//  动态生成Tab栏
    _genTabs() {
        const tabs = [
            {
                screen: props => <Course {...this.props} tabLabel={"推荐"} />,
                navigationOptions: {
                    title: '推荐',
                }
            }
        ]
        //	this.state.dataArray	数据源
        //	brandName Tab栏的名字
        this.state.dataArray.map((item, index) => {
            tabs[`${index + 1}`] = {
                screen: props => <Course {...this.props} tabLabel={item.brandName} />,
                navigationOptions: {
                    title: item.brandName
                }
            }
        })
        console.log('tabs=====>', {...this.props.navigation.navigate.length === 0 });
        console.log('this.state.dataArray=====>', this.state.dataArray);
        return tabs;
    }

    render() {
        console.log('this._genTabs()=====>', this._genTabs());
        const MaterialTopTabNavigator = createAppContainer(createMaterialTopTabNavigator(
            this._genTabs(),
        ))

        return (
            <SafeAreaView style={styles.container}>

                <View style={styles.title}>
                    <Text style={{ fontSize: 20 }}>选择课程</Text>
                </View>

                <MaterialTopTabNavigator />

            </SafeAreaView>
        );
    }
}

//	Course	通过this.state.dataArray[index + 1].brandCode来获取参数
class Course extends React.Component {
	//获取课程列表
    getClass(index) {
        if (index === 0) {
            const params = {
                channelCode: channelCode,
                totalCodes: apprecommend1 + ',' + apprecommend2 + ',' + apprecommend3,
                top: 100,
                brandCodes: this.state.subject ? this.state.subject : ''
            }
            getClassRecommend(params).then(value => {
                console.log('推荐课', value);
                if (value.code === 200) {
                    this.setState({
                        classData: value.data
                    })
                }
            })
        } else {
            const params = {
                channelCode: channelCode,
                brandCode: this.state.dataArray[index + 1].brandCode + ',' + this.state.subject,
            }
            console.log('app', this.state.dataArray[index + 1].brandCode + ',' + this.state.subject)
            getClassList(params).then(value => {
                if (value.code === 200) {
                    this.setState({
                        classData: value.data
                    })
                }
            });
        }
    }
}

我想请问老师，怎么在动态滑动Tab栏的时候获取我的brandCode来加载数据