code: function dir2TreeStr(){
      argD = Type.isBoolean(argD) ? "./" : trimAndDelQuotes(argD);
      let dirJson,djOpt;
      try{
          djOpt = {
              // preChars:{
              //     directory: ":open_file_folder: ",
              //     file:":page_facing_up: "
              // },
              exclude:{
                  outExcludeDir: true //将过滤掉的文件夹输出
              },
              extChars:{
                  directory: " /"
              },
              maxDepth: argM
          };
          dirJson = dir2Json(argD, djOpt);
      }catch(e3){
          errorOut("Gen Json via dir failed: " + e3.toString());
          dirJson = false;
      }
      if(!dirJson){
          if(dirJson===null){
              warningOut("The directory '" + argD + "' is empty! (exclude-filter: .git|.svn|.idea|node_modules|bower_components )");
          }
      }else if(Type.isString(dirJson)){
          warningOut("The directory '" + argD + "' is '" + dirJson + "'");
      }else{
          // 间距配置和上面不一样
          s = Type.isNaN(s) ? 2 : s;
          v = Type.isNaN(v) ? 0 : v;
          jsonName = (djOpt.preChars && djOpt.preChars.directory || "") + argD.replace(/\\/g,"/");
          outputVal = false;
          _doMain(dirJson,true);
      }
  }
docs: convert directory to tree-string