1.在methods外面添加beforeRouteLeave方法

beforeRouteLeave(to, from, next) {
        console.log('beforeRouteLeave come in');
        if(this.isSaved === false){
            setTimeout(()=>{
                this.$confirm('您还未保存页面内容，是否保存当前更改?', '提示', {
                confirmButtonText: '是',
                cancelButtonText: '否',
                type: 'warning',
                closeOnClickModal:false,
                closeOnPressEscape:false,
                closeOnHashChange: false
            }).then(() => {
                this.saveItem()
                this.isSaved=true
                next()
            }).catch(()=>{
                this.$message({
                    message:'配置明细未改变',
                    type:'info'
                })
                this.isSaved=true
                next()
            })
            },200)
        }else{
            next()
        }     
     },

2.在页面保存方法里添加开关
当进入这个方法时，就是主动保存，这时按钮会变成true

async saveItem() {
            this.isSaved=true;
            console.log(this.updateItemData);
            if (this.updateData.length > 0) {
                for (let i = 0; i < this.updateData.length; i++) {
                    this.addItemform = {};
                    this.addItemform.examConfigId = this.updateData[i].examConfigId;
                    this.addItemform.categoryId = this.updateData[i].categoryId;
                    this.addItemform.subjectTypeId = this.updateData[i].subjectTypeId;
                    this.addItemform.itemDifficult = this.updateData[i].itemDifficult;
                    this.addItemform.num = this.updateData[i].num;
                    this.addItemform.score = this.updateData[i].score;
                    this.addItemform.itemStatus = this.updateData[i].itemStatus;
                    console.log(this.addItemform);
                    await this.selAddItemData();
                }
                this.$message.success('添加明细成功');
                this.updateData = [];
            }
            if (this.updateItemData.length > 0) {
                for (let i = 0; i < this.updateItemData.length; i++) {
                    this.editItemform = {};
                    this.editItemform.itemId = this.updateItemData[i].itemId;
                    this.editItemform.categoryId = this.updateItemData[i].categoryId;
                    this.editItemform.subjectTypeId = this.updateItemData[i].subjectTypeId;
                    this.editItemform.itemDifficult = this.updateItemData[i].itemDifficult;
                    this.editItemform.num = this.updateItemData[i].num;
                    this.editItemform.score = this.updateItemData[i].score;
                    this.editItemform.itemStatus = this.updateItemData[i].itemStatus;
                    this.editItemform.itemVersion = this.updateItemData[i].itemVersion;
                    console.log(this.editItemform);
                    await this.editItemData();
                }
                this.$message.success('修改明细成功');
                this.updateItemData = [];
            }
            if (this.delItemList.length > 0) {
                console.log(this.delItemList);
                await this.delItemData();
                this.$message.success('删除   ' + this.delItemList.length + '   条明细成功');
                this.delItemList = [];
            }
        }
    }