將文件（圖片爲例子）保存到 自己指定的沙盒文件夾中 並取出來 待用

 /*________保存圖片到沙河路徑文件夾_____________**littleSun_zheng**/

    //先把圖片轉成NSData
    NSData *data  = UIImageJPEGRepresentation(image,.000000005);
   
    //文件管理器
    NSFileManager *fileManager = [NSFileManagerdefaultManager];
    //拼接要存放東西的文件夾
      NSString *pathDocuments = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)objectAtIndex:0];

   NSString *createPath = [NSStringstringWithFormat:@"%@/EcmChatMyPic", pathDocuments];
    // 判斷文件夾是否存在，如果不存在，則創建
    if (![[NSFileManagerdefaultManager]fileExistsAtPath:createPath]) {

//如果沒有就創建這個 想創建的文件夾   （）
        [fileManager createDirectoryAtPath:createPathwithIntermediateDirectories:YESattributes:nilerror:nil];

       
        //然後保存
        NSString * DocumentsPath = [NSHomeDirectory()stringByAppendingPathComponent:@"Documents/EcmChatMyPic"];
        NSString *imgFileName = [NSStringstringWithFormat:@"/%@.jpg",fileName];
        [fileManager createFileAtPath:[DocumentsPath stringByAppendingString:imgFileName]contents:data attributes:nil];
       
    } else {
        //文件夾存在   直接保存
        NSString * DocumentsPath = [NSHomeDirectory()stringByAppendingPathComponent:@"Documents/EcmChatMyPic"];
       
        NSString *imgFileName = [NSStringstringWithFormat:@"/%@.jpg",fileName];
       
        [fileManager createFileAtPath:[DocumentsPath stringByAppendingString:imgFileName]contents:data attributes:nil];
    }
   
 
    //存完之後 接着就取出來 發送
    NSString * DocumentsPath = [NSHomeDirectory()stringByAppendingPathComponent:@"Documents/EcmChatMyPic"];
    NSString *imgFileName = [NSStringstringWithFormat:@"/%@.jpg",fileName];
    NSString * filePath = [[NSString alloc] initWithFormat:@"%@%@",DocumentsPath,imgFileName];
   //取出圖片 等待 你的使用

   UIImage *img = [UIImage imageWithContentsOfFile:filePath];