Vue技术开发中遇到的文件上传和下载问题及解决方案

<template>
  <div>
    <input type="file" v-on:change="onFileChange" accept=".jpg,.jpeg,.png" />
  </div>
</template>

<script>
export default {
  methods: {
    onFileChange(event) {
      const file = event.target.files[0];
      const extension = file.name.split(".").pop().toLowerCase();
      const allowedTypes = ["jpg", "jpeg", "png"];

      if (!allowedTypes.includes(extension)) {
        alert("只能上传jpg、jpeg、png格式的文件！");
        return;
      }

      // 处理文件上传逻辑...
    },
  },
};
</script>

<template>
  <div>
    <input type="file" v-on:change="onFileChange" />
  </div>
</template>

<script>
export default {
  data() {
    return {
      maxFileSize: 5 * 1024 * 1024, // 5MB
    };
  },
  methods: {
    onFileChange(event) {
      const file = event.target.files[0];

      if (file.size > this.maxFileSize) {
        alert("文件大小不能超过5MB！");
        return;
      }

      // 处理文件上传逻辑...
    },
  },
};
</script>

<template>
  <div>
    <input type="file" v-on:change="onFileChange" />
    <button v-on:click="uploadFile">上传</button>
    <div>{{ progress }}%</div>
  </div>
</template>

<script>
import axios from "axios";

export default {
  data() {
    return {
      file: null,
      progress: 0,
    };
  },
  methods: {
    onFileChange(event) {
      this.file = event.target.files[0];
    },
    uploadFile() {
      const formData = new FormData();
      formData.append("file", this.file);

      axios
        .post("/upload", formData, {
          headers: {
            "Content-Type": "multipart/form-data",
          },
          onUploadProgress: (progressEvent) => {
            this.progress = Math.round(
              (progressEvent.loaded / progressEvent.total) * 100
            );
          },
        })
        .then((response) => {
          console.log(response.data);
        })
        .catch((error) => {
          console.error(error);
        });
    },
  },
};
</script>

<template>
  <div>
    <button v-on:click="downloadFile">下载</button>
  </div>
</template>

<script>
export default {
  methods: {
    downloadFile() {
      const fileName = "示例文件.txt";
      const fileUrl = "/download?fileName=" + encodeURIComponent(fileName);

      window.open(fileUrl);
    },
  },
};
</script>

<template>
  <div>
    <button v-on:click="downloadFile">下载</button>
  </div>
</template>

<script>
export default {
  methods: {
    downloadFile() {
      // 检查用户登录状态和权限...
      if (userLoggedIn && userHasPermission) {
        const fileName = "示例文件.txt";
        const fileUrl = "/download?fileName=" + encodeURIComponent(fileName);

        window.open(fileUrl);
      } else {
        alert("您没有下载权限！");
      }
    },
  },
};
</script>