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- //单例模式设计
- //单例的类Common
- class Common{
- //factory关键字
- //工厂模式: 单例公开访问点
- factory Common()=>_getInstance();
- //静态未初始化对象--单例对象
- static Common _instance;
- static Common _getInstance(){
- if(_instance==null){
- _instance=Common._internal();
- }
- return _instance;
- }
- Common._internal();//初始化函数
- //SD卡根路径
- String sDCardDir;
- //存放收藏文件夹目录的文件
- String favoriteDir;
- List<String> favoriteFileList=new List<String>();
- String favoriteAll='';
- String getFileSize(int fileSize){
- String str ='';
- if(fileSize<1024){
- str='${fileSize.toStringAsFixed(2)}B';//toStringAsFixed(2) 保留两位小数 四舍五入
- }else if(1024<=fileSize&&fileSize<1048576){
- str='${(fileSize/1024).toStringAsFixed(2)}KB';
- }else if(1048576<=fileSize&&fileSize<1073741824){
- str = '${(fileSize / 1024 / 1024).toStringAsFixed(2)}MB';
- }
- return str;
- }
- String selectIcon(String ext) {
- String iconImg = 'assets/images/unknown.png';
- switch (ext) {
- case '.ppt':
- case '.pptx':
- iconImg = 'assets/images/ppt.png';
- break;
- case '.doc':
- case '.docx':
- iconImg = 'assets/images/word.png';
- break;
- case '.xls':
- case '.xlsx':
- iconImg = 'assets/images/excel.png';
- break;
- case '.pdf':
- iconImg = 'assets/images/pdf.png';
- break;
- case '.jpg':
- case '.jpeg':
- case '.png':
- iconImg = 'assets/images/image.png';
- break;
- case '.txt':
- iconImg = 'assets/images/txt.png';
- break;
- case '.flac':
- case '.mp3':
- iconImg = 'assets/images/audio.png';
- break;
- case '.mp4':
- iconImg = 'assets/images/video.png';
- break;
- case '.rar':
- case '.zip':
- iconImg = 'assets/images/zip.png';
- break;
- case '.psd':
- iconImg = 'assets/images/psd.png';
- break;
- case '.apk':
- iconImg='assets/images/apk.png';
- break;
- default:
- iconImg = 'assets/images/file.png';
- break;
- }
- return iconImg;
- }
- }
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