Vue+mui實(shí)現(xiàn)圖片的本地緩存示例代碼

const menu = {
 state: {
  products: {},
  GLOBAL_CONFIG:GLOBAL_CONFIG['GLOBAL_CONFIG']
 },
 mutations: {
  get_product: function (state, products) {
    //商品列表
    state.products = products;
    for(let i = 0; i < state.products.length; i++){
      if(state.products[i]['image'] != null){
        // state.products[i]['image'] = state.GLOBAL_CONFIG['base64Header'] + state.products[i]['image'];
        //下載圖片到本地
        this.commit('imgCache',state.products[i]);
      }else{
        //添加默認(rèn)圖片
        state.products[i]['image'] = require("../assets/file.png");
      }
    }
  },
  imgCache: function (state,imgObj) {
    mui.plusReady(function(){
      // 1. 轉(zhuǎn)換網(wǎng)絡(luò)圖片地址為本地緩存圖片路徑，判斷該圖片是否存在本地緩存
      // http://...jpg -> md5
      // 緩存目錄 _downloads/image/(md5).jpg
      let image_url      = imgObj.image;
      let image_md5      = md5(image_url);
      // 緩存本地圖片url
      let local_image_url   = '_downloads/image/'+image_md5+'.jpg';
      // 平臺(tái)絕對(duì)路徑
      let absolute_image_path = plus.io.convertLocalFileSystemURL(local_image_url);
      console.log(absolute_image_path);
      // 判斷本地是否存在該文件，存在就就直接使用，否則就下載
      plus.io.resolveLocalFileSystemURL( absolute_image_path, function( entry ) {
        if(entry){
          imgObj.image = plus.io.convertLocalFileSystemURL(local_image_url);
        }else{
          download_img();
        }
      }, function ( e ) {
        console.log("Resolve file URL failed: ");
        download_img();
      } );
      function download_img(){
        // filename:下載任務(wù)在本地保存的文件路徑
        let download_task = plus.downloader.createDownload(image_url, {
          filename: local_image_url
        }, function(download, status) {
          // 下載失敗,刪除本地臨時(shí)文件
          if(status != 200){
            console.log('下載失敗,status'+status);
            if(local_image_url != null){
              plus.io.resolveLocalFileSystemURL(local_image_url, function(entry) {
                entry.remove(function(entry) {
                  console.log("臨時(shí)文件刪除成功" + local_image_url);
                  // 重新下載圖片
                  download_img();
                }, function(e) {
                  console.log("臨時(shí)文件刪除失敗" + local_image_url);
                });
              });
            }
          }else{
            // 把下載成功的圖片顯示
            // 將本地URL路徑轉(zhuǎn)換成平臺(tái)絕對(duì)路徑
            console.log("下載成功" + local_image_url);
            imgObj.image = plus.io.convertLocalFileSystemURL(local_image_url);
          }
        });
        download_task.start();
      }    
    });
  }
 },
 actions: {
 }
}