ios 如何在没有 XIB 文件的情况下以编程方式更新 Xcode 中的 UILabel？
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How to update a UILabel in Xcode programmatically without XIB files?
提问by dcrawkstar
I'm stuck :(
In my application I require an update from CLLocationManager every time it gets an update to a new position. I am not using XIB/NIB files, everything I coded I have done programmatically. To the code:
the .h
我被卡住了:(
在我的应用程序中，每次更新到新位置时，我都需要从 CLLocationManager 进行更新。我没有使用 XIB/NIB 文件，我编码的所有内容都是以编程方式完成的。代码：
.h
@interface TestViewController : UIViewController
UILabel* theLabel;
@property (nonatomic, copy) UILabel* theLabel;
@end
the .m
他们
...
-(void)loadView{
....
UILabel* theLabel = [[UILabel alloc] initWithFrame:CGRectMake(0.0,0.0,320.0,20.0)];
theLabel.text = @"this is some text";
[self.view addSubView:theLabel];
[theLabel release]; // even if this gets moved to the dealloc method, it changes nothing...
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
NSLog(@"Location: %@", [newLocation description]);
// THIS DOES NOTHING TO CHANGE TEXT FOR ME... HELP??
[self.view.theLabel setText:[NSString stringWithFormat: @"Your Location is: %@", [newLocation description]]];
// THIS DOES NOTHING EITHER ?!?!?!?
self.view.theLabel.text = [NSString stringWithFormat: @"Your Location is: %@", [newLocation description]];
}
...
Any ideas, or help?
任何想法或帮助？
(this was all hand jammed so please forgive me if it looks kinda gacked) I can provide more info if needed.
（这都是手卡住的，所以如果它看起来有点卡住，请原谅我）如果需要，我可以提供更多信息。
回答by GorillaPatch
Your loadView method is wrong. You do not set the instance variable properly but instead you generate a new local variable. Change it to the following by omitting the UILabel *and do not release itbecause you want to keep a reference around to the label to set the text later.
您的 loadView 方法是错误的。您没有正确设置实例变量，而是生成了一个新的局部变量。通过省略 将其更改为以下内容UILabel *并且不要释放它，因为您希望保留对标签的引用以稍后设置文本。
-(void)loadView{
....
theLabel = [[UILabel alloc] initWithFrame:CGRectMake(0.0,0.0,320.0,20.0)];
theLabel.text = @"this is some text";
[self.view addSubView:theLabel];
}
- (void) dealloc {
[theLabel release];
[super dealloc];
}
Then later directly access the variable like this:
然后稍后直接访问变量，如下所示：
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
NSLog(@"Location: %@", [newLocation description]);
theLabel.text = [NSString stringWithFormat: @"Your Location is: %@", [newLocation description]];
}
回答by David Schlesinger
Are you synthesizing theLabel in your .m file...? If not, you need to, I believe.
你在你的 .m 文件中合成 theLabel 吗...？如果没有，你需要，我相信。
