Connect a UILabel in Interface Builder and XCode?

2020-02-13 13:33发布

I am trying to do something as simple as add a Label to a View in XCode and IB and I can't figure out how to do it. All the samples I find online are for older versions of IB so the directions aren't correct.

I have a label on my .xib file, in my Controller.h file I have an IBOutlet UILabel declared with a Property set up.

In my Controller.m file I synthesized that Property.

In Interface Builder, I cannot for the LIFE of me figure out how to associate my label in my code with the Label on the .xib. Whenever I try to drag the Connection to File's Owner, the only option that shows up is "View".

If I look at the Controller under the Library Window of Interface Builder, the Label shows up as a UILabel under Outlets. I am pretty sure that it used to be a type "id", but it automatically shows up as UILabel and if I try to add an "id" one, it doesn't work either.

Can someone point me to somewhere to explain this stupid thing? It should not be this difficult to make a label have text.

4条回答
时光不老,我们不散
2楼-- · 2020-02-13 14:13

Assume that you have a viewController and a xib file which has a UILabel on this. The steps to connection the UiLabel (also the xib file) your viewController are:

1) In the header file, create UiLabel object and property for it

IBOutlet UILabel *label;

@Property (Nonatomic, retain) IBOutlet UILabel *label;

and synchthesize it in implement file

2) Open your xib file in Interface Builder

Double click on "File's Owner" then select the viewController in dropdownlist of pop-up windows to connect your xib file to controller

3) right-click on file's owner, on the pop-up dialog:

  • point and drag the plush (+) next to "View" and drop it on View row
  • point and drag the plush (+) next to "label" and drop it on the label on the view

=> now the label and the view on xib file is connected to you controller

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3楼-- · 2020-02-13 14:18

Try this: click on the File's Owner icon to select it, and go to the Inspector's Identity tab (the 4th tab) and check the value of the Class setting. My guess is that's it's currently set to UIViewController.

Since the class that has the IBOutlet you declared is (or should be) a subclass of UIViewController, you'll need to change the class name to the name of your subclass (e.g., MyController, or whatever it's currently named).

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做个烂人
4楼-- · 2020-02-13 14:24

Assuming your view is called ExampleView. Click on the file owner and then press ⌘+4. This will highlight the identity box. Make sure that the class name is the same as the name of your class.

Save and close Interface Builder and then go into Xcode and verify:

// ExampleViewController.h
#import <UIKit/UIKit.h>

@class ExampleViewController;
@interface ExampleViewController : UIViewController {

    IBOutlet UILabel *label;
}

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

@end

In your .m file:

// ExampleViewController.m
#import "ExampleViewController.h"

@implementation ExampleViewController

@synthesize label;

Then save the xcode files and open up your ExampleView. Drag a label onto the view. You are not supposed to connect that label to the Files owner.

INSTEAD YOU CLICK THE FILEOWNER. HIT ⌘+2 this will open the connections box. then you will see your outlet. Click and connect that to your label.

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成全新的幸福
5楼-- · 2020-02-13 14:31

Make sure your property line looks like this:

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

Leave (or set) the type of the label as UILabel in Interface Builder. If that doesn't work, try File -> Reload All Class Files in Interface Builder. Your code looks good, but CardNameLabel should start with a lower-case 'c'.

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