for (Book *book in postilBooksArr) {  //待操作的文件
   NSString *path = [NSString stringWithFormat:@"%@%ld/",kBookFilePath,book.sid];  //文件所在路徑
   NSFileManager *fileManager = [NSFileManager defaultManager];
   NSDirectoryEnumerator *enumerator = [fileManager enumeratorAtPath:path];  // 劃重點(diǎn)
   for (NSString *fileName in enumerator) { //  fileName 就是遍歷到的每一個(gè)文件文件名
        if ([fileName hasPrefix:@"zztemp_"]) {
           NSString *moveFileName = [fileName stringByReplacingOccurrencesOfString:@"temp_" withString:@""];
           NSString *moveToPath = [path stringByAppendingPathComponent:[NSString stringWithFormat:@"%@",moveFileName]];  // 替換的文件的終極路徑
           [fileManager removeItemAtPath:moveToPath error:nil]; // 將終極路徑的文件刪除
           NSString *filePath = [path stringByAppendingPathComponent:[NSString stringWithFormat:@"%@",fileName]]; //用于替換的文件的路徑
           [fileManager moveItemAtPath:filePath toPath:moveToPath error:nil]; // 替換
         }
    }
}