xcode 获取 NSTextField 的 keyDown 事件
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Get keyDown event for an NSTextField
提问by Laurent Crivello
In xcode last version, I am trying to get the keyDown event of an NSTextField. However, despite following multiple tutorials on the internet (delegates, controllers...), I still can't receive it.
在 xcode 上一个版本中，我试图获取 NSTextField 的 keyDown 事件。但是，尽管在互联网上学习了多个教程（委托、控制器......），我仍然无法接收它。
Any easy hint for me ?
对我有什么简单的提示吗？
Thanks !
谢谢 ！
回答by Scott Jenkins
I got sick of all the non answers to do it some other way people so I put my nose down and figured out a way to make this work. This isn't using keydown event directly but it is using the keydown in the block. And the behavior is exactly what I wanted.
我厌倦了人们以其他方式做这件事的所有非答案，所以我低下头并想出了一种方法来使这项工作发挥作用。这不是直接使用 keydown 事件，而是使用块中的 keydown。而这种行为正是我想要的。
Subclass the text field
子类化文本字段
.h
。H
@interface LQRestrictedInputTextField : NSTextField
.m
.m
In the become first responder setup a local event
在成为第一响应者设置一个本地事件
static id eventMonitor = nil;
- (BOOL)becomeFirstResponder {
BOOL okToChange = [super becomeFirstResponder];
if (okToChange) {
[self setKeyboardFocusRingNeedsDisplayInRect: [self bounds]];
if (!eventMonitor) {
eventMonitor = [NSEvent addLocalMonitorForEventsMatchingMask:NSKeyDownMask handler:^(NSEvent *event) {
NSString *characters = [event characters];
unichar character = [characters characterAtIndex:0];
NSString *characterString=[NSString stringWithFormat:@"%c",character];
NSArray *validNonAlphaNumericArray = @[@" ",@"(",@")",@"[",@"]",@":",@";",@"\'",@"\"",@".",@"<",@">",@",",@"{",@"}",@"|",@"=",@"+",@"-",@"_",@"?",@"#",
@(NSDownArrowFunctionKey),@(NSUpArrowFunctionKey),@(NSLeftArrowFunctionKey),@(NSRightArrowFunctionKey)];
if([[NSCharacterSet alphanumericCharacterSet] characterIsMember:character] || character == NSCarriageReturnCharacter || character == NSTabCharacter || character == NSDeleteCharacter || [validNonAlphaNumericArray containsObject:characterString ] ) { //[NSCharacterSet alphanumericCharacterSet]
} else {
NSBeep();
event=nil;
}
return event;
} ];
}
}
NSLog(@"become first responder");
return okToChange;
}
remove the event once the textfield editing ends
文本字段编辑结束后删除事件
Also if you're using ARC I noticed you might need to assign the textview string to the stringValue. I nslog'd the stringValue and the value was retained. Without the nslog I had to assign the notification object string to the stringValue to keep it from getting released.
另外，如果您使用的是 ARC，我注意到您可能需要将 textview 字符串分配给 stringValue。我记录了 stringValue 并保留了该值。如果没有 nslog，我必须将通知对象字符串分配给 stringValue 以防止它被释放。
-(void) textDidEndEditing:(NSNotification *)notification {
[NSEvent removeMonitor:eventMonitor];
eventMonitor = nil;
NSTextView *textView=[notification object];
self.stringValue=textView.string;
}
回答by Justin Boo
You can subclass NStextField and use keyUp that works for NSTextField.
您可以继承 NStextField 并使用适用于 NSTextField 的 keyUp。
in .h
在.h
@interface MyTextField : NSTextField <NSTextFieldDelegate>
in .m
在.m
-(void)keyUp:(NSEvent *)theEvent {
NSLog(@"Pressed key in NStextField!");
}
回答by Darren
Add UITextFieldDelegate to your .h like this
像这样将 UITextFieldDelegate 添加到您的 .h
@interface ViewController : UIViewController <UITextFieldDelegate> {
Then you can use this to detect every key press in a text field
然后您可以使用它来检测文本字段中的每个按键
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
Return YES to allow the character that was pressed to be inserted into the field but you can add whatever code you need in here.
返回 YES 以允许将按下的字符插入到该字段中，但您可以在此处添加您需要的任何代码。
