1.本次使用的是uview的u-upload上传组件
2.选择图库使用了wx.chooseImage API

原理： 使用disabled禁用掉自带的选择文件的方法， 然后使用插槽自定义一个上传文件的按钮和方法

image.png

image.png

image.png

完整代码

<template>
    <view class="img-wrap">
        <u-upload :accept="accept" :fileList="fileList" 
            @afterRead="afterRead" @delete="deletePic" 
            name="1" multiple 
            :maxCount="20" uploadIcon="plus"
            disabled>
            <view @click="WxChooseImage" class="slot-btn" hover-class="slot-btn__hover" hover-stay-time="150">
                <u-icon name="photo" size="30" color="#c0c4cc"></u-icon>
                <span class="slot-txt">添加图片</span>
            </view>
        </u-upload>
    </view>
</template>

<script setup>
    import {
        computed,
        getCurrentInstance,
        ref
    } from 'vue';

    const {
        proxy
    } = getCurrentInstance()

    const props = defineProps({
        modelValue: {
            type: Array,
            default: () => ([])
        },
        accept: {
            type: String,
            default: 'image'
        },
    })
    const emit = defineEmits(['update:modelValue'])


    const uploadFileUrl = ref(import.meta.env.VITE_APP_BASE_API + "/file/upload"); // 上传文件服务器地址
    const ossUrl = ref(import.meta.env.VITE_APP_OSS_ADD); // 上传文件服务器地址

    const fileList = computed({
        get: () => {
            let returnArr = []
            if (props.modelValue.length == 0) return props.modelValue
            props.modelValue.forEach(item => {
                if (typeof item == 'string') {
                    returnArr.push({
                        url: ossUrl.value + item,
                        filePath: item,
                        status: 'success',
                        message: '',
                    })
                } else {
                    returnArr.push({
                        ...item,
                        filePath: item.url,
                    })
                }
            })
            return returnArr
        },
        set: (val) => {
            emit('update:modelValue', val)
        }
    })

    // 删除图片
    const deletePic = (event) => {
        fileList.value = fileList.value.filter((item, index) => (index != event.index))
    };

    // 新增图片
    const afterRead = async (event) => {
        // 当设置 mutiple 为 true 时, file 为数组格式，否则为对象格式
        await uploadFileFn([].concat(event.file))
    };
    // 文件上传前-参数转化
    const uploadFileFn = async (lists) => {
        if (!lists || lists && !lists.length) return
        let fileListLen = fileList.value.length;
        for (let i = 0; i < lists.length; i++) {
            const res = await uploadFilePromise(lists[i].url, lists[i]);
            if (res.code == 200) {
                fileList.value = [...fileList.value.map(item => item.filePath), res.data]
                fileListLen++;
            } else {
                proxy.$modal.msgError(`上传失败`)
            }
        }
    }

    // 文件上传中-调用接口
    const uploadFilePromise = (url, item) => {
        const token = uni.getStorageSync('App-Token')
        return new Promise((resolve, reject) => {
            uni.uploadFile({
                url: uploadFileUrl.value, // 仅为示例，非真实的接口地址
                filePath: url,
                name: 'file',
                header: {
                    "Authorization": 'Bearer ' + token,
                    "Content-Type": "multipart/form-data"
                },
                formData: { 
                    name: uploadFileUrl.value, 
                    url: uploadFileUrl.value,
                },
                success: (res) => {
                    resolve(JSON.parse(res.data));
                },
            });
        });
    };

    const WxChooseImage = () => {
        var tempFilePaths;
        wx.chooseImage({
            sizeType: ['original', 'compressed'],  // 可以指定是原图还是压缩图，默认二者都有
            // sourceType: ['album', 'camera'],  // 可以指定来源是相册还是相机，默认二者都有
            sourceType: ['album'],  // 指定相册
            success: async function(res) {
                // 返回选定照片的本地文件路径列表，tempFilePaths可以作为img标签的src属性显示图片
                tempFilePaths = res.tempFiles.map(x => ({
                    ...x,
                    url: x.path,
                    name: x.path,
                }));

                await uploadFileFn([].concat(tempFilePaths))
            }
        })
    }
</script>

<style>
.img-wrap {
    position: relative;
}
.img-wrap-mask {
    position: absolute;
    width: calc(100% - 90px);
    height: 100%;
    right: 0;
    bottom: 0;
    z-index: 999;
}

.slot-btn {
    width: 80px;
    height: 80px;
    display: flex;
    justify-content: center;
    align-items: center;
    background: rgb(244, 245, 246);
    border-radius: 3px;
    flex-direction: column;
}

.slot-btn__hover {
    background-color: rgb(235, 236, 238);
}
.slot-txt {
    font-size: 12px;
    color: #999;
    padding-top: 2px;
}
</style>