Question

我有4个NSMutableArray，并且在启动时它们已正确初始化。在我的代码的一部分中，我将这些数组的内容写入单个plist文件，并且已创建这些plist文件并将其添加到项目中。我有4个写入文件的实例，由于某种原因，只有前2个写入文件成功（didWrite和didWrite2）但didWrite3和didWrite 4一直返回“nope”意味着写入不成功。下面是在applicationDidFinishLaunching中初始化和分配数组的代码：

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *DataPath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"Data.plist"];
    NSString *inkDatesPath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"inkDates.plist"];
    NSString *inkFontPath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"inkFont.plist"];
    NSString *inkColorPath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"inkColor.plist"];
    NSFileManager *fileManager = [NSFileManager defaultManager];

    if (![fileManager fileExistsAtPath: DataPath])
    {
        inks=[[NSMutableArray alloc] init ];
         NSLog(@"initialized inks as new");
    }
    else inks=[[NSMutableArray alloc] initWithContentsOfFile:DataPath];

    if (![fileManager fileExistsAtPath: inkDatesPath])
    {
        inkDates=[[NSMutableArray alloc] init ];
    }
    else inkDates=[[NSMutableArray alloc] initWithContentsOfFile:inkDatesPath];

    if (![fileManager fileExistsAtPath: inkFontPath])
    {
        inkFont=[[NSMutableArray alloc] init ];
    }
    else inkFont=[[NSMutableArray alloc] initWithContentsOfFile:inkFontPath];

    if (![fileManager fileExistsAtPath: inkColorPath])
    {
        inkColor=[[NSMutableArray alloc] init ];
        NSLog(@"initialized inkColor as new");
    }
    else { 
        inkColor=[[NSMutableArray alloc] initWithContentsOfFile:inkColorPath];
        NSLog(@"initialized inkColor as copy");

当应用程序首次启动时，我将“初始化的inkColor视为新的”，但我仍然无法编写。墨水和墨水日期写得不错，但其他两个不合适。这是我的代码试图写入plist文件：

  NSError *error;
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); //1
    NSString *documentsDirectory = [paths objectAtIndex:0]; //2


    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"Data.plist"]; //3
    NSFileManager *fileManager = [NSFileManager defaultManager];

    if (![fileManager fileExistsAtPath: path])
    {
        NSString *bundle=[[NSBundle mainBundle] pathForResource:@"Data" ofType:@"plist"];
        [fileManager copyItemAtPath:bundle toPath: path error:&error]; //6
    }

    NSString *pathDates = [documentsDirectory stringByAppendingPathComponent:@"inkDates.plist"]; //3
    NSFileManager *fileManagerDates = [NSFileManager defaultManager];

    if (![fileManagerDates fileExistsAtPath: pathDates])
    {
        NSString *bundle=[[NSBundle mainBundle] pathForResource:@"inkDates" ofType:@"plist"];
        [fileManagerDates copyItemAtPath:bundle toPath: pathDates error:&error]; //6
    }

    NSFileManager *fileManagerFont = [NSFileManager defaultManager];
    NSString *pathFont = [documentsDirectory stringByAppendingPathComponent:@"inkFont.plist"];
    if (![fileManagerFont fileExistsAtPath: pathFont])
    {
        NSString *bundle=[[NSBundle mainBundle] pathForResource:@"inkFont" ofType:@"plist"];
        [fileManagerFont copyItemAtPath:bundle toPath: pathFont error:&error]; //6
    }

    NSFileManager *fileManagerColor = [NSFileManager defaultManager];
    NSString *pathColor = [documentsDirectory stringByAppendingPathComponent:@"inkColor.plist"];
    if (![fileManagerFont fileExistsAtPath: pathColor])
    {
        NSString *bundle=[[NSBundle mainBundle] pathForResource:@"inkColor" ofType:@"plist"];
        [fileManagerColor copyItemAtPath:bundle toPath: pathColor error:&error]; //6
    }


    NSDate *date = [NSDate date];
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"EEEE, MMMM d, YYYY"];
    NSString *dateString = [dateFormat stringFromDate:date];  
    [dateFormat release];

            [appDelegate.inks addObject:[inkTextField text]];
            [appDelegate.inkDates addObject:dateString];
            [appDelegate.inkFont addObject:[inkTextField font]];
            [appDelegate.inkColor addObject:[inkTextField textColor]];
            NSLog(@"inkColor count: %i", [appDelegate.inkColor count]);
            NSLog(@"Wrote to new index");

    BOOL didWrite=[appDelegate.inks writeToFile: path atomically:YES];
    if(didWrite==YES)
       NSLog(@"didWrite");
    else NSLog(@"nope");



    BOOL didWrite2;
    didWrite2=[appDelegate.inkDates writeToFile: pathDates atomically:YES];
    if(didWrite2==YES)
        NSLog(@"didWrite");
    else NSLog(@"nope");


    BOOL didWrite3;
    didWrite3=[appDelegate.inkFont writeToFile: pathFont atomically:YES];
    if(didWrite3==YES)
        NSLog(@"didWrite");
    else NSLog(@"nope");

    BOOL didWrite4;
    didWrite4=[appDelegate.inkColor writeToFile: pathColor atomically:YES];
    if(didWrite4==YES)
        NSLog(@"didWrite");
    else NSLog(@"nope");

Answer 1

您正在使用writeToFile尝试编写正确的plist。其文件说明：

此方法以递归方式验证所有包含的对象是否为   属性列表对象（NSData，NSDate，NSNumber，   NSString，NSArray或NSDictionary）在写出文件之前，和   如果所有对象都不是属性列表对象，则返回NO，因为   结果文件不是有效的属性列表。

如果字典的内容都是属性列表对象，则该文件   通过此方法编写的可用于初始化新字典   类方法dictionaryWithContentsOfFile：或实例方法   initWithContentsOfFile：

UIColor和UIFont不在列表中。

通常，您可能希望使用NSCoding协议（使用NSCoder对象），这样可以更有效地序列化数据。然而，即使这样，也没有好的方法来存储UIFont对象 - 它们不符合NSCoding并且无法序列化。您应该存储字体系列/大小，然后使用自定义代码在加载数据时恢复字体。

为什么我在尝试写入plist文件时失败了

1 个答案: