无法让 NSEnumerator 显示数组中的下一项

发布于 2024-12-06 13:19:04 字数 1075 浏览 0 评论 0原文

我是 Objective-C 的新手，我已经在网上研究了几周了。每个站点上的几乎每个示例都是相同的，并且并没有完全让我清楚如何将其集成到 Xcode 4 应用程序的代码中。

随处可见的例子是：

NSEnumerator* theEnum = [some_array objectEnumerator]; id 对象；或 id some_object = NULL; while(obj = [theEnum nextObject]) { //do

some_object = NULL;/ id obj; 我想如果我能更好地理解什么代表我可以自己解决。

在我的代码中我有三个数组。我希望每次用户单击“下一步”按钮时都能够在 UILabel 字段中的每个数组中显示一个对象，直到所有对象都显示出来。

NSArray1 = 1,2,3

NSArray2 = 约翰、吉尔、乔什 NSArray3 = 男孩，女孩，男孩

当按下下一个按钮时，您将看到 1、约翰和男孩。下次你会看到 2，吉尔和女孩，最后看到 3，乔希和男孩。

下面是基本示例，不是我的实际代码。

number = [[NSArray alloc] initWithObjects:@"1",@"2",@"3", nil];
name = [[NSArray alloc] initWithObjects:@"John",@"Jill",@"Josh", nil];
gender = [[NSArray alloc] initWithObjects:@"boy",@"girl",@"boy", nil];

NSEnumerator *enum = [number objectEnumerator];
id obj; (??What is this?? And how to connect to the statement below??)

while ((obj = [enumNumber nextObject])) {

self.numberItem.text = ??
self.nameItem.text = ??
self.genderItem.text = ??

谢谢

原文

I am new to Objective-C and I have researched this online for weeks now. Almost every example is the same on every site and does not fully make it clear to me how to integrate it into my code for an Xcode 4 App.

The example seen everywhere is:

NSEnumerator* theEnum = [some_array objectEnumerator]; id obj; or id some_object = NULL; while(obj = [theEnum nextObject]) { //do something...

I think if I better understood what id some_object = NULL;/ id obj; represents I could figure it out on my own.

In my code I have three arrays. I want to be able to display one object in each array in a UILabel field every time the user clicks the Next button until all of them have been displayed.

NSArray1 = 1,2,3

NSArray2 = John, Jill, Josh
NSArray3 = boy, girl, boy

When the next button is pushed you would see 1, John and boy. The next time you would see 2, Jill and girl and finally 3, Josh and boy.

Below is basic example, not my actually code.

number = [[NSArray alloc] initWithObjects:@"1",@"2",@"3", nil];
name = [[NSArray alloc] initWithObjects:@"John",@"Jill",@"Josh", nil];
gender = [[NSArray alloc] initWithObjects:@"boy",@"girl",@"boy", nil];

NSEnumerator *enum = [number objectEnumerator];
id obj; (??What is this?? And how to connect to the statement below??)

while ((obj = [enumNumber nextObject])) {

self.numberItem.text = ??
self.nameItem.text = ??
self.genderItem.text = ??

Thanks

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夏日浅笑〃 2024-12-13 13:19:04

id obj 只是包含您正在查看的当前变量的变量。在此代码中，由于您的 NSArray 都包含字符串，因此您可以使用 NSString *obj 代替。

枚举器一次只能枚举一个集合。如果您想一起循环遍历所有三个，请使用传统的 for 循环：

for(unsigned int i = 0; i < number.count; i++) {
    self.numberItem.text = [number objectAtIndex:i];
    self.nameItem.text = [name objectAtIndex:i];
    self.genderItem.text = [gender objectAtIndex:i];
}

id obj is just the variable containing the current variable you're looking at. In this code, since your NSArrays all contain string, you could use NSString *obj instead.

An enumerator can only enumerate one collection at a time. If you want to loop through all three of them together, use a traditional for loop:

for(unsigned int i = 0; i < number.count; i++) {
    self.numberItem.text = [number objectAtIndex:i];
    self.nameItem.text = [name objectAtIndex:i];
    self.genderItem.text = [gender objectAtIndex:i];
}

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