如何处理嵌套属性列表

Question

美好的一天！

我在iOS中做一个嵌套的属性列表有问题。

因此，有两个UITextField s将接受一个随机值，然后将其保存到属性列表。问题是，当我输入第二个值时，它将覆盖我的属性列表中的第一个值。

如何处理或编写嵌套属性列表？

这里是我尝试代码：

- (IBAction)writeToPlist:(id)sender 
{ 
    NSLog(@"Write."); 

    NSString *finalPath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:@"Data.plist"]; 

    NSMutableDictionary *fruitDictionary = [[NSMutableDictionary alloc] init]; 

    NSString *fruitName = [[NSString alloc] initWithString:[fruitNameField text]]; 
    NSString *fruitDescription = [[NSString alloc] initWithString:[fruitDescriptionField text]]; 

    NSDictionary *fruitDetail = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:fruitName, fruitDescription, nil] 
                  forKeys:[NSArray arrayWithObjects:@"Fruit", @"Description", nil]]; 

    NSMutableDictionary *fruitPlist = [[NSMutableDictionary alloc] initWithContentsOfFile:finalPath]; 
    NSMutableArray *fruitArray = [fruitPlist objectForKey:fruitName]; 

    if (fruitArray == nil) { 
     fruitArray = [[NSMutableArray alloc] init]; 
    } 

    [fruitDictionary setObject:fruitDetail forKey:fruitName]; 

    [fruitArray addObject:fruitDictionary]; 
    [fruitArray writeToFile:finalPath atomically:YES]; 

    [[self presentingViewController] dismissViewControllerAnimated:YES 
                 completion:nil]; 
} 

输出是：

<plist version="1.0"> 
<array> 
    <dict> 
     <key>Apple</key> 
     <dict> 
      <key>Description</key> 
      <string>Red</string> 
      <key>Fruit</key> 
      <string>Apple</string> 
     </dict> 
    </dict> 
</array> 
</plist> 

我希望发生的是：

<plist version="1.0"> 
<array> 
    <dict> 
     <key>Apple</key> 
     <dict> 
      <key>Description</key> 
      <string>Red</string> 
      <key>Fruit</key> 
      <string>Apple</string> 
     </dict> 
    </dict> 
    <dict> 
     <key>Banana</key> 
     <dict> 
      <key>Description</key> 
      <string>Yellow</string> 
      <key>Fruit</key> 
      <string>Banana</string> 
     </dict> 
    </dict> 
</array> 
</plist> 

顺便说一句，是我的代码可以接受或不？我的意思是，有什么办法可以缩短它吗？

Answer 1

所以我用你的代码发挥各地，并找出一些问题。

这里是我写的和测试的。这是工作。

NSString *finalPath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:@"Data.plist"]; 
    NSMutableDictionary *fruitDictionary = [[NSMutableDictionary alloc] init]; 
    NSString *fruitName = fName; 
    NSString *fruitDescription = fDetail; 
    NSDictionary *fruitDetail = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:fruitName, fruitDescription, nil] 
                  forKeys:[NSArray arrayWithObjects:@"Fruit", @"Description", nil]]; 
    NSMutableArray *fruitPlist = [[NSMutableArray alloc] initWithContentsOfFile:finalPath]; 


if (fruitPlist == nil) { 
     fruitPlist = [[NSMutableArray alloc] init]; 
    } 
    [fruitDictionary setObject:fruitDetail forKey:fruitName]; 
    [fruitPlist addObject:fruitDictionary]; 
    [fruitPlist writeToFile:finalPath atomically:YES]; 

说明： 你都拿到在你的代码内字典您的plist的SROOT。但是在你想要拥有NSArray的根目录下。这就是为什么，这：

NSMutableArray *fruitPlist = [[NSMutableArray alloc] initWithContentsOfFile:finalPath]; 

在我的代码fName和fDetail只是我传递的变量。
希望它有帮助！

Answer 2

您首先从plist中检索字典，然后编写一个Array。其中一个是错误的。基于 上要也许尝试这样的：

NSMutableArray *fruitPlist = [[NSMutableArray alloc] initWithContentsOfFile:finalPath]; 

NSDictionary *newFruit; 

for (NSDictionary *fruit in fruitPlist) { 
    if ([fruit objectForKey:fruitName]) newFruit = fruit; 
} 

if (!newFruit) { 
    newFruit = [[NSDictionary alloc] init]; 
    [fruitPlist addObject:newFruit]; 
} 
else { 
    NSInteger index = [fruitPlist indexOfObject:newFruit]; 

    // modify newFruit as you wish 

    [fruitPlist replaceObjectAtIndex:index withObject:newFruit]; 

} 

[fruitPlist writeToFile:finalPath atomically:YES];