[C/OC的那点事儿]Objective-C实现学生成绩管理系统(5)

p>        [studentArray sortUsingDescriptors:[NSArray arrayWithObject:sortByAge]];  

p>  

p>      

p>    }  

p>    else if ([key isEqualToString:@"score"])  

p>    {  

p>        NSSortDescriptor *sortByScore = [NSSortDescriptor sortDescriptorWithKey:@"score" ascending:ascending];  

p>          

p>        [studentArray sortUsingDescriptors:[NSArray arrayWithObject:sortByScore]];  

p>  

p>      

p>    }  

p>  

p>  

p>}  

p>  

p>-(void)writeToFile  

p>{  

p>    NSString *path = [NSString stringWithFormat:@"/Users/len/Desktop"];  

p>    NSLog(@"请输入你所要写入的文件名字:");  

p>    char sfilename[20];  

p>    scanf("%s",sfilename);  

p>      

p>    NSString *filename = [NSString stringWithUTF8String:sfilename];  

p>    NSString *filepath = [path stringByAppendingPathComponent:filename];  

p>      

p>    NSData *data = [NSKeyedArchiver archivedDataWithRootObject:studentArray ];  

p>      

p>    [data writeToFile:filepath atomically:YES];  

p>      

p>  

p>  

p>      

p>}  

p>  

p>-(void)readFromFile  

p>{  

p>    NSString *path = [NSString stringWithFormat:@"/Users/len/Desktop"];  

p>    NSLog(@"请输入你所要读取的文件名字:");  

p>    char sfilename[20];  

p>    scanf("%s",sfilename);  

p>      

p>    NSString *filename = [NSString stringWithUTF8String:sfilename];  

p>    NSString *filepath = [path stringByAppendingPathComponent:filename];  

p>    

p>    //NSMutableData *data = [[NSMutableData alloc]initWithContentsOfFile:filepath];  

p>      

p>    NSMutableData *Data = [NSMutableData dataWithContentsOfFile:filepath];  

p>    self.studentArray = [NSKeyedUnarchiver unarchiveObjectWithData:Data];  

p>      

p>     

p>}  

p>  

p>-(void)motifyStudent  

p>{  

p>    NSLog(@"请输入你要修改的同学的学号:");  

p>    int studentID;  

p>    scanf("%d",&studentID);  

p>      

p>    for (Student *stu in studentArray) {  

p>        if (stu.stuID == studentID) {