问题设置UILabel的价值（iPhone SDK） [英] Problem setting Value for UILabel (iPhone SDK)

问题描述

我在iPhone SDK上相当新，所以如果这个答案显而易见，请原谅我。

I'm reasonably new at the iPhone SDK, so please forgive me if this answer's ridiculously obvious.

我有一个连接到.xib文件的ViewController（他们被称为FirstViewController）

I have a ViewController connected to a .xib file (they are called FirstViewController)

我还有一个名为MyCustomClass的自定义类。在这个课程中，我有一个这样的方法：

I also have a custom class called MyCustomClass. In this class, I have a method like this:

- (void)setTheText {
    [myLabel setText:@"foo"];
}

我想调用此方法在FirstViewController中设置标签中的文本。 xib

I want to call this method to set the text in a label in FirstViewController.xib

到目前为止，我已经这样做了：

So far, I have done this:

将对象拖到Interface Builder中，将类设置为：MyCustomClass
将IBOutlet'myLabel'从MyCustomClass连接到视图中的UILabel。

Dragged in an "Object" into Interface Builder, and set the class to: MyCustomClass Connected up the IBOutlet 'myLabel' from MyCustomClass to a UILabel in the view.

但是，当我运行程序时，按下按钮设置标签（在FirstViewController.m中），如：

However, when I run the program, and press the button to set the label (which is in FirstViewController.m), something like:

- (IBAction)doSomething:(id)sender {
   MyCustomClass *customClass = [MyCustomClass alloc] init];
   [customClass setTheText];
}

但这并没有设定。 NSLog（@％@，[myLabel text]）; 返回（null）

This doesn't set though. NSLog(@"%@",[myLabel text]); returns (null)

Xcode显示没有错误或警告，可能出现什么问题？

Xcode shows no errors or warnings, what could be wrong?

谢谢，

Michael

其他信息：

MyCustomClass.h的接口：

Interface to MyCustomClass.h:

#import <UIKit/UIKit.h>

@interface MyCustomClass : NSObject {
    UILabel *myLabel;
}

@property (nonatomic, retain) IBOutlet UILabel *myLabel;

- (void)setTheText;

@end

推荐答案

您的这里的customClass实例与NIB完全无关。您已使用+ alloc实例化了一个新对象。如果你想在你的NIB中修改特定的MyCustomClass，那么FirstViewController需要一个指向它的IBOutlet。

Your instance of customClass here is completely unrelated to the NIB. You've instantiated a new object using +alloc. If you want to modify the specific MyCustomClass in your NIB, then FirstViewController needs an IBOutlet that points to it.

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