如何清理Vue.Js中的输入

我在功能完成后干净的输入几乎没有问题 有人可以告诉我我做错了什么 功能完成后，请尝试清理输入 但是我没有任何结果 这是我在Vue组件中的代码

<form role="form">
                                    <div class="card-body">
                                        <div class="form-group">
                                            <label for="file">Upload File</label>
                                            <div class="input-group">
                                                <div class="custom-file">
                                                    <input type="file" class="custom-file-input" id="file" ref="file" v-on:change="handleFileUpload">
                                                    <label class="custom-file-label" for="file">Choose file</label>
                                                </div>
                                            </div>
                                        </div>
                                    </div>
                                    <div class="card-footer">
                                        <button v-on:click="onClickUploadAccounts" class="btn btn-primary">Upload</button>
                                        <button v-on:click="onClickSetLoader" class="btn btn-primary">Loader</button>
                                    </div>
                                </form>

methods: {
        handleFileUpload(){
            this.file = this.$refs.file.files[0]
        },
        onClickUploadAccounts(){
            let formData = new FormData();
            formData.append('file', this.file);
            this.$store.commit('imports/setIsLoad', true)
            axios.post( '/admin-account-import',
                formData,
                {
                    headers: {
                        'Content-Type': 'multipart/form-data'
                    }
                }
            ).then(() => {
                console.log('SUCCESS!!')
                this.$store.commit('imports/setIsLoad', false)
                this.file = ''
                formData.delete('file')
                formData.append('file', this.file = '')
            })
                .catch(() => {
                    console.log('FAILURE!!');
                });
        },
        onClickSetLoader()
        {
            this.$refs.file.files = ''
        },

    },