JS实现全选，取消全选，正常选择

//点击选择方法
onUserIdsChange(selVal) {
if (this.form.groupUserIds.includes(-1) && !this.isSelectAll) {
// 全选
this.nickNames = []
this.isSelectAll = true
this.form.groupUserIds = []
this.groupUserOption.forEach(item => {
item.value != -1 && this.form.groupUserIds.push(item.value)
if(this.form.groupUserIds.length !== 0 && item.subscribe !== true){
this.onShow = true
this.nickNames.push(item.label)
}
})
this.groupUserOption[0].label = '取消全选'

} else if (this.isSelectAll && this.form.groupUserIds.includes(-1)) {
// 取消全选
this.isSelectAll = false
this.groupUserOption[0].label = '全选'
this.form.groupUserIds = []
this.onShow = false
this.nickNames = []
} else {
// 正常选择
this.nickNames = []
this.form.groupUserIds = selVal
if(this.form.groupUserIds.length === this.groupUserOption.length - 1){
this.groupUserOption[0].label = '取消全选'
}else{
this.groupUserOption[0].label = '全选'
}
if(this.form.groupUserIds.length !== 0){
this.groupUserOption.forEach(item2 => {
this.form.groupUserIds.forEach(item => {
if(item2.value === item && item2.subscribe !== true){
this.onShow = true
this.nickNames.push(item2.label)
}else if(item2.value === item && item2.subscribe === true){
this.onShow = false
}
})
})
}
else{
this.onShow = false
this.nickNames = []
}
}
}
},