react-native 自制多选功能

//多选js部分

changeMoreSelect =(index) =>{

const set = new Set(this.state.changeArr)

set.has(index) ? set.delete(index) : set.add(index)

//通过下标查询,如果set返回true则删除,反之则添加下标

this.setState({changeArr: [...set]},()=>{

console.log(this.state.changeArr)

})

}

// view层

{this.state.answer.map((item,index) =>{

//循环数组

return(

<TouchableOpacity key={index} style={{paddingLeft:15,marginTop:33}} onPress={()=>this.changeMoreSelect(index)}>

<View style = {{flexDirection:"row",alignItems:"center",}}>

//判断下标显示点击图片切换

{this.state.changeArr.indexOf(index) === -1 ?

<Image ../../assets/images/changeOff.png")}/>:

<Image ../../assets/images/changeOn.png")}/>

}

{/A/}

{item.a_text}

)

}