haowanShow/miniprogram/pages/chat/file-save-manager.js

const MAX_SIZE = 10400000;
let wholeSize = 0;
setTimeout(() => {
    wx.getSavedFileList({
        success: savedFileInfo => {
            let {fileList} = savedFileInfo;
            !!fileList && fileList.forEach(item => {
                wholeSize += item.size;
            });
            // console.log(wholeSize, '总大小');

        }
    });
});
export default class FileSaveManager {
    constructor() {

    }

    static set(msg, localPath) {
        wx.setStorage({key: msg.saveKey, data: localPath})
    }

    static get(msg) {
        return wx.getStorageSync(msg.saveKey);
    }

    static saveFileRule({tempFilePath}) {
        return new Promise((resolve, reject) => {
            wx.getFileInfo({
                filePath: tempFilePath,
                success: tempFailInfo => {
                    let tempFileSize = tempFailInfo.size;
                    // console.log('本地临时文件大小', tempFileSize);
                    if (tempFileSize > MAX_SIZE) {
                        reject({errMsg: '文件过大'});
                        return;
                    }
                    wx.getSavedFileList({
                        success: savedFileInfo => {
                            let {fileList} = savedFileInfo;
                            if (!fileList) {
                                reject({errMsg:'获取到的fileList为空，请检查你的wx.getSavedFileList()函数的success返回值'});
                                return;
                            }
                            //这里计算需要移除的总文件大小
                            let sizeNeedRemove = wholeSize + tempFileSize - MAX_SIZE;
                            if (sizeNeedRemove >= 0) {
                                //按时间戳排序，方便后续移除文件
                                fileList.sort(function (item1, item2) {
                                    return item1.createTime - item2.createTime;
                                });
                                let sizeCount = 0;
                                for (let i = 0, len = fileList.length; i < len; i++) {
                                    // console.log('移除的文件1', sizeCount);
                                    if ((sizeCount += fileList[i].size) >= sizeNeedRemove) {
                                        for (let j = 0; j < i; j++) {
                                            // console.log('移除的文件2', fileList[j].filePath);
                                            wx.removeSavedFile({
                                                filePath: fileList[j].filePath,
                                                success: function () {
                                                    wholeSize -= fileList[j].size;
                                                    // console.log('移除成功', wholeSize);
                                                }
                                            });
                                        }
                                        break;
                                    }
                                }
                            }

                            wx.saveFile({
                                tempFilePath: tempFilePath,
                                success: res => {
                                    wholeSize += tempFileSize;
                                    resolve({savedFilePath: res.savedFilePath});
                                },
                                fail: reject
                            });
                        },
                        fail: reject
                    });
                }
            });
        });

    }
}