使用官方的代码，value(可用v-model双向绑定)控制modal框的显示隐藏，会出现只要点击了确定按钮，v-model绑定的值自动变为false，关闭modal框，想要的效果：点击确定按钮判断条件决定modal框是否关闭

解决方案一：

<template>
    <div>
        <button style="margin-left: 10px;" @click="btn">demo按钮</button>
        <Modal 
            :value="modalConfig.modalShow"
            title="新增"
            :transfer="false"
            :mask-closable="false"
            :width="400"
            @on-ok="Submit"
            @on-cancel="cancel"
            :loading="modalConfig.loading"
        >
            <Input v-model.trim="age"></Input>
        </Modal>
    </div>
</template>

<script>
    export default{
        data(){
            return {
                age:'男',
                modalConfig:{
                    modalShow:false,
                    loading:true
                }
            }
        },
        methods:{
            btn(){
                this.modalConfig.modalShow = true
            },
            Submit(){
                if(this.age !== '男'){
                    this.modalConfig.loading = false;
                    this.$nextTick(() => {
                        this.modalConfig.loading = true;
                    })
                    this.$Message.error("输入框必须为男!");
                }else{
                    this.modalConfig.modalShow = false
                    this.$Message.error("成功");
                }
            },
            cancel(){
                this.modalConfig.modalShow = false
            }
        }
    }
</script>

<style>

</style>

解决方案二：

<template>
    <div>
        <button style="margin-left: 10px;" @click="btn">demo按钮</button>
        <Modal 
            v-model="modalConfig.modalShow"
            title="新增"
            :transfer="false"
            :mask-closable="false"
            :width="400"
        >
            <Input v-model.trim="age"></Input>
            <div slot="footer">
				<Button type="primary" @click="cancel">取消</Button>
				<Button type="primary" @click="submit">确定</Button>
			</div>
        </Modal>
    </div>
</template>

<script>
    export default{
        data(){
            return {
                age:'男',
                modalConfig:{
                    modalShow:false,
                }
            }
        },
        methods:{
            btn(){
                this.modalConfig.modalShow = true
            },
            submit(){
                if(this.age !== '男'){
                    this.$Message.error("输入框必须为男!");
                }else{
                    this.modalConfig.modalShow = false
                    this.$Message.error("成功");
                }
            },
            cancel(){
                this.modalConfig.modalShow = false
            }
        }
    }
</script>

<style>

</style>