迭代 NSTableview 或 NSArrayController 来获取数据

发布于 2025-01-03 21:00:08 字数 878 浏览 1 评论 0原文

我有一个绑定到 NSArrayController 的 NSTableview。表/数组控制器包含核心数据“人”实体。人员由 GUI 用户添加到 NSTableview 中。

假设一个人实体看起来像

NSString* Name;
int Age;
NSString* HairColor;

现在我想迭代数组控制器中存储的内容以在其中执行某些操作。我想要做的实际操作并不重要，我真的不想陷入我试图对信息做什么的困境。它只是迭代 NSArraycontroller 中保存的所有内容，这让我感到困惑。我有 C++ 和 C# 背景，对 Cocoa 很陌生。假设我想构建一个 NSMutableArray，其中包含 1 年后来自 nsarraycontroller 的每个人。

所以我想做一些类似的事情，

NSMutableArray* mutArray = [[NSMutableArray alloc] init];

foreach(PersonEntity p in myNsArrayController)  // foreach doesn't exist in obj-c
{

  Person* new_person = [[Person alloc] init];
  [new_person setName:p.name];
  [new_person setHairColor:p.HairColor];
  [new_person setAge:(p.age + 1)];
  [mutArray addObject:new_person];

}

我相信唯一阻止我做类似上面代码的事情是 Obj-c 中不存在 foreach 。我只是不知道如何迭代 nsarraycontroller。

注意：这是针对 OSX 的，所以我打开了垃圾收集

原文

I have an NSTableview which s bound to a NSArrayController. The Table/Arraycontroller contains Core Data "Person" entities. The people are added to the NSTableview by the GUI's user.

Let's say a person entity looks like

NSString* Name;
int Age;
NSString* HairColor;

Now I want to iterate over what is stored in the array controller to perform some operation in it. The actual operation I want to do isn't important I don't really want to get bogged down in what I am trying to do with the information. It's just iterating over everything held in the NSArraycontroller which is confusing me. I come from a C++ and C# background and am new to Cocoa. Let's say I want to build a NSMutableArray that contains each person from nsarraycontroller 1 year in the future.

So I would want to do something like

NSMutableArray* mutArray = [[NSMutableArray alloc] init];

foreach(PersonEntity p in myNsArrayController)  // foreach doesn't exist in obj-c
{

  Person* new_person = [[Person alloc] init];
  [new_person setName:p.name];
  [new_person setHairColor:p.HairColor];
  [new_person setAge:(p.age + 1)];
  [mutArray addObject:new_person];

}

I believe the only thing holding me back from doing something like the code above is that foreach does not exist in Obj-c. I just don't see how to iterate over the nsarraycontroller.

Note: This is for OSX so I have garbage collection turned on

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墨洒年华 2025-01-10 21:00:08

您正在寻找快速枚举。

对于你的例子，类似

for (PersonEntity *p in myNsArrayController.arrangedObjects)
{
    // Rest of your code
}

You're looking for fast enumeration.

For your example, something like

for (PersonEntity *p in myNsArrayController.arrangedObjects)
{
    // Rest of your code
}

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冰魂雪魄 2025-01-10 21:00:08

您还可以使用块进行枚举。例如：

[myNsArrayController enumerateObjectsUsingBlock:^(id object, NSUInteger index, BOOL *stop)
 {
       PersonEntity *p = object;
       // Rest of your code
 }];

两种方法各有利弊。这些在这个问题的答案中进行了深入讨论：

Objective-C enumerateUsingBlock vs fast enumeration?

您可以在 Apple 的 WWDC 2010 视频中找到有关块的精彩教程。他们说在苹果公司“一直”使用块。

You can also enumerate using blocks. For example:

[myNsArrayController enumerateObjectsUsingBlock:^(id object, NSUInteger index, BOOL *stop)
 {
       PersonEntity *p = object;
       // Rest of your code
 }];

There's pro's and cons to both approaches. These are discussed in depth in the answer to this question:

Objective-C enumerateUsingBlock vs fast enumeration?

You can find a great tutorial on blocks in Apple's WWDC 2010 videos. In that they say that at Apple they use blocks "all the time".

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