I create an UIButton and use titleLable.text to set text ,but the text is not seen in the button so I replace it with setText method, and it show the text, I just want to know why the titleLable.text is not working
UIButton *button=[UIButton buttonWithType:UIButtonTypeCustom];
button.titleLabel.text=#"text";
Then used like below
[button setTitle:#"text" forState:UIControlStateNormal];
Because titleLabel is a readonly property.
titleLabel
A view that displays the value of the currentTitle property for a
button. (read-only)
#property(nonatomic, readonly, retain) UILabel *titleLabel >
Discussion
Although this property is read-only, its own properties are
read/write. Use these properties primarily to configure the text of
the button. For example:
UIButton *button = [UIButton buttonWithType: UIButtonTypeRoundedRect];
button.titleLabel.font = [UIFont systemFontOfSize: 12];
button.titleLabel.lineBreakMode = UILineBreakModeTailTruncation;
Do not use the label object to set the text color or the shadow color.
Instead, use the setTitleColor:forState: and
setTitleShadowColor:forState: methods of this class to make those
changes.
The titleLabel property returns a value even if the button has not
been displayed yet. The value of the property is nil for system
buttons.
Availability
Available in iOS 3.0 and later.
Declared In UIButton.h
Please refer UIButton Class for more details.
Midhun's answer, while completely true, doesn't answer the question. As he says, the label property is read-only but its properties are not, including the text property.
The reason setting the text does not work is that the button itself will be setting the text internally, depending on the control state. This will override anything you've set as the text.
This is why you use setTitle:forControlState: instead. The button will use the value for the normal state for all other states, unless you tell it otherwise, but if you never set a title for any control state, it will not show the label.
Related
I create a class RadioButton that inherited from UIButton ,and rewrite the method layoutSubViews where reset the frame of self.imageView and self.titleLabel ,when I call the method setImage:forState: of RadioButton instance,it does not work, but the method radioButton.imageView.image = [UIImage imageNamed:#""] work. It is an interesting problem ,I appreciate so much if anyone know why and share the reason .
When we set title,image for button we need to use below code
For Button
[button setTitle:#"Your Title" forState:UIControlStateNormal];
For Image
[button setImage:[UIImage imageNamed:#"Your Image Name"] forState:UIControlStateNormal];
why should not we use titleLabel
Do not use the label object to set the text color or the shadow color.
Instead, use the setTitleColor:forState: and
setTitleShadowColor:forState: methods of this class to make those
changes.
The titleLabel property returns a value even if the button has not
been displayed yet. The value of the property is nil for system
buttons.
why should we use setTitle
Use this method to set the title for the button. The title you
specify derives its formatting from the button’s associated label
object. If you set both a title and an attributed title for the
button, the button prefers the use of the attributed title over this
one.
At a minimum, you should set the value for the normal state. If a
title is not specified for a state, the default behavior is to use the
title associated with the UIControlStateNormal state. If the value for
UIControlStateNormal is not set, then the property defaults to a
system value.
For Image
I have a UITextField for search in my Application.
When user taps on the Clear Button in the right of the Search Text Field I need to hide this textfield.
So, can I show the Clear Button then TextField is empty? I need to do it always to provide the ability hiding TextField.
Just create a Custom button and set it as rightView for your TextField
UIButton *cleanBtn = [UIButton buttonWithType:UIButtonTypeCustom];
// Set clear image for your button
[cleanBtn setImage:img forState:UIControlStateNormal];
[cleanBtn addTarget:self action:#selector(cleanTextField:) forControlEvents:UIControlEventTouchUpInside];
yourTextField.rightViewMode = UITextFieldViewModeAlways;
yourTextField.rightView = cleanBtn;
I tried to fix this issue with creating a custom button and setting the rightView of my text field. It did not solve my problem. There is no button on the right view.
I have added UIButton in Interface Builder using Auto Layout and placed it on my text field. It works. It's strange solution but it works.
After looking over the internet and other SO questions(this one is great iOS: UIButton titleLabel -- does it do anything at all?), it is unclear to me what is the difference between these two, more accurately, how these two work.
I know that setTitle:forState: let me set text of the button for different states(Normal, Disabled,Highlighted etc.). I know, as well, that titleLabel is read only, but its properties are read/write.
At this point you might ask: What is the problem then?
I will explain it through example. I have following hierarchy:
UITableViewCell - MyView - MyButton
MyView is xib in which, through interface builder, I set button. When I set buttons title like:
self.myButton.titleLabel.text = #"Something"; // some string I get from server
It works. But if I try the similar approach when only MyView is included (somewhere else in the project) and try:
myView.myButton.titleLabel.text = #"Something else";
It doesn't work. Let me be more specific. In one part of the second(even in viewDidApper) buttons title is what I want. After that, the buttons label returns to its default value. The one I set in the interface builder. When I change to
[myView.myButton setTitle:#"Something else" forState:UIControlStateNormal];
It works as expected.
What I want to know is why does this happen? It is unclear to me why does this glitch occurs with the title? Is this strange thing documented somewhere(looked over apple documentation)? Is it possible to get implementation of setTitle:forState:?
I'm not sure how the internals of UIButton are actually implemented but this is a guess. There are times when iOS needs to redraw the button ie. the button is tapped so the button's state changes (let's say from UIControlStateNormal to UIControlStateHighlighted). Then iOS would find the title associated to UIControlStateHighlighted then display that text by using something like.
myButton.titleLabel.text = #"Title for UIControlStateHighlighted";
Sample scenario:
[myButton setTitle:#"Normal" forState:UIControlStateNormal];
[myButton setTitle:#"Highlighted" forState:UIControlStateHighlighted];
// somewhere in the code, you call this to change the label
myButton.titleLabel.text = #"Something else";
// when user taps the button, iOS will do something like
myButton.titleLabel.text = #"Highlighted"; // will overwrite "Something Else"
// when user releases, iOS will again do something like
myButton.titleLabel.text = #"Normal"; // will overwrite "Highlighted"
so it's required to use setTitle:forState: in order to associate the given title to a certain state. The instances where iOS redraws the button is of course not limited to the the user interacting with the button. It could also be triggered by layout changes.
You should not use button.titleLabel.text = to set the button title.
The documentation for the titleLabel property says
Although this property is read-only, its own properties are read/write. Use these properties primarily to configure the text of the button. For example:
UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];
button.titleLabel.font = [UIFont systemFontOfSize: 12];
button.titleLabel.lineBreakMode = NSLineBreakByTruncatingTail;
Do not use the label object to set the text color or the shadow color. Instead, use the setTitleColor(:for:) and setTitleShadowColor(:for:) methods of this class to make those changes. To set the actual text of the label, use setTitle(_:for:) (button.titleLabel.text does not let you set the text).
I normally don't set button titles in interface builder, but do it in the viewDidLoad, and get the title from Localizable.strings..
You must use setTitle:forState and setTitleColor:forState to change text and color. All other label properties can be changed directly though.
"Do not use the label object to set the text color or the shadow color. Instead, use the setTitleColor:forState: and setTitleShadowColor:forState: methods of this class to make those changes."
-source
I need to check if some object has text property. For example it can be an UIButton or an UILabel. But there is an issue between properties that display text for an UIButton and for an UILabel.
This is the difference:
For an UIButton we set text using setTitle: method, but for an UILabel we using another one named setText:
What I need to do with this:
I need to get all subviews and if these subviews have text property I need to change this property value with some text.
So of course I can check class of object and setup needed property, but maybe we have another approach to do it without checking class of object.
for (id item in [self.view subviews])
{
if ([item respondsToSelector:#selector(text)])
[item setText:#"text"]; // change text for UILabel
else if ( [item respondsToSelector:#selector(setTitle:forState:)])
[item setTitle:#"text" forState:UIControlStateNormal]; // change text for UIButton
}
How can I add a clear button (cross inside a circle) for UITextView like UITextField has?
Based on the answer from GhostRider a more accurate and up to date implementation:
int kClearButtonWidth = 15;
int kClearButtonHeight = kClearButtonWidth;
//add the clear button
self.clearButton = [UIButton buttonWithType:UIButtonTypeCustom];
[self.clearButton setImage:[UIImage imageNamed:#"UITextFieldClearButton.png"] forState:UIControlStateNormal];
[self.clearButton setImage:[UIImage imageNamed:#"UITextFieldClearButtonPressed.png"] forState:UIControlStateHighlighted];
self.clearButton.frame = CGRectMake(0, 0, kClearButtonWidth, kClearButtonHeight);
self.clearButton.center = CGPointMake(self.textView.frame.size.width - kClearButtonWidth , kClearButtonHeight);
[self.clearButton addTarget:self action:#selector(clearTextView:) forControlEvents:UIControlEventTouchUpInside];
[self.textView addSubview:self.clearButton];
And the method
- (void)clearTextView:(id)sender{
self.textView.text = #"";
}
You can use this images for the two states of the button:
just make a uibutton and put it on uitextview and set its action for clear text view;
uitextview.frame = (0,0,320,416);
uibutton.frame = (310,0,10,10);
[uibutton setimage:#"cross.png" forcontrolstate:uicontrolstatenoraml];
[uibutton addTarget:self action:#selector(clearButtonSelected:) forControlEvents:UIControlEventTouchUpInside];
-(void)clearButtonSelected{
uitextview=#"";
}
hope you want to clear the text view text when you click on cross button above is help
if not understand then i can send you proper program for that
From product perspective, if you're going to have a clear button, you probably want to use a UITextField instead of a UITextView and UITextField supports a clear button natively - set the clearButtonMode property as such:
UITextField *textfield = ...;
textfield.clearButtonMode = UITextFieldViewModeAlways;
See screenshot:
You could use UITextFieldViewModeWhileEditing to only present the clear button while the user is actively updating the content.
There's nothing built in like there is for the UITextField. You'd have to add the view yourself (probably a UIButton) and place it correctly and also somehow get the text to wrap around it correctly. (And I don't think the latter is really possible.)
Maybe instead you should display a toolbar above the keyboard (or an inputAccessoryView if you're targeting 3.2 and later) that provides a clear button.
For me changing the .frame or the .contentInset properties did not work.
For me the best result came from:
1) adding a UIView to the controller, give it round corners and a border to mimic a UITextView.
self.viewTextBackground.layer.borderColor = [UIColor colorWithRed:171/255.0 green:171/255.0 blue:171/255.0 alpha:1.0].CGColor;
self.viewTextBackground.layer.borderWidth = 1.0f;
self.viewTextBackground.layer.cornerRadius = 9.0f;
2) place UITextView on top of this UIView. Place it so that the borders of the underlying UIView stay visible.
3) give the UITextView round corners:
self.textNote.layer.cornerRadius = 9.0f;
3) Make its width fe. 30pixels less compared to the underlying UIView. You now have space for a clear-button.
4) simply add a UIButton to your controller and place it in the top-right corner of the underlying UIView.
5) change the buttons properties: set its type to 'custom' and set its image to the image of a grey cross.
6) bind an action to the button te clear the UITextView
You can add a clear button like the one in the attached screenshot with minimal coding. Just follow these steps:
Select the storyboard and drag a UIButton into your UITextView
Set the buttons constraints
Assign a title or a background image
Create the button's IBOutlet reference and the action (see onClearPressed(_:) below) for "Touch Up Inside" in the ViewController
Implement the textViewDidChange(_:) UITextViewDelegate delegate method, and make sure to set the button's isEnabled property based on the textfield content, e.g.:
func textViewDidChange(_ textView: UITextView) {
clearButton.isEnabled = !textView.text.isEmpty
}
Implement the onClearPressed(_:) action:
#IBAction func onClearPressed(_ sender: Any) {
textView.text = ""
clearButton.isEnabled = false
}
That's it.