ios 如何知道 UITextView 是否有焦点
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how to know whether a UITextView has a focus or not
提问by JAHelia
I know the becomeFirstRespondermethod to set a focus on a control, but how to know whether that control (for ex. UITextView) is currently having focus on it or not ?
我知道在becomeFirstResponder控件上设置焦点的方法，但是如何知道该控件（例如UITextView）当前是否正在关注它？
EDIT: the problem is that I want (for example) to change the background color of the UITextView when it receives focus, where should I put the isFirstResponder call exactly ? should I use notifications in this case ?
编辑：问题是我想（例如）在接收焦点时更改 UITextView 的背景颜色，我应该把 isFirstResponder 调用准确地放在哪里？在这种情况下我应该使用通知吗？
thanks so much in advance.
非常感谢。
回答by Mehul Mistri
if([txtView isFirstResponder]){
//Has Focus
} else {
//Lost Focus
}
This is UITextView's delegate method,
这是 UITextView 的委托方法，
- (BOOL)textViewShouldBeginEditing:(UITextView *)aTextView{
//Has Focus
return YES;
}
This is lost focus
这是失去焦点
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{
if ([text isEqualToString:@"\n"]){
//Lost Focus
[textView resignFirstResponder];
}
return YES;
}
回答by Boris Nikolic
Use the UITextField delegate methods. When textField got focus the(bacame first responder)
使用 UITextField 委托方法。当 textField 获得焦点时（第一响应者）
- (void)textFieldDidBeginEditing:(UITextField *)textField;will be fired,
- (void)textFieldDidBeginEditing:(UITextField *)textField;将被解雇，
and when it lost focus
当它失去焦点时
- (void)textFieldDidEndEditing:(UITextField *)textField;will be fired.
- (void)textFieldDidEndEditing:(UITextField *)textField;将被解雇。
