如何從iOS應用程式的自定義鍵盤檢索擊鍵？

主題專注於自定義鍵盤的視覺元素,但我正在努力瞭解如何從這個鍵盤中檢索擊鍵.

Apple提供了inputView機制,可以輕鬆地將自定義鍵盤與UITextField或UITextView相關聯,但它們不提供將生成的擊鍵傳送回相關物件的功能.基於這些物件的典型委託,我們期望三個函式：一個正常字元,一個用於退格,一個用於輸入.然而,沒有人似乎明確界定這些功能或如何使用它們.

如何為我的iOS應用程式建立自定義鍵盤並從中檢索擊鍵？

格雷格的方法應該是有效的,但我有一種方法,不需要關於文字欄位或文字檢視的鍵盤.實際上,您可以建立鍵盤的單個例項並將其分配到多個文字欄位和/或文字檢視.鍵盤處理知道哪一個是第一個響應者.

這是我的做法我不會顯示用於建立鍵盤佈局的任何程式碼.這很簡單.此程式碼顯示所有管道.

編輯：這已經更新,以正確處理UITextFieldDelegate textField：shouldChangeCharactersInRange：replacementString：和UITextViewDelegate textView：shouldChangeTextInRange：replacementText :.

標頭檔案：

@interface SomeKeyboard : UIView <UIInputViewAudioFeedback>

@end

執行檔案：

@implmentation SomeKeyboard {
id<UITextInput> _input;
BOOL _tfShouldChange;
BOOL _tvShouldChange;
}

- (id)init {
self = [super init];
if (self) {
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(checkInput:) name:UITextFieldTextDidBeginEditingNotification object:nil];
}

return self;
}

// This is used to obtain the current text field/view that is now the first responder
- (void)checkInput:(NSNotification *)notification {
UITextField *field = notification.object;

if (field.inputView && self == field.inputView) {
_input = field;

_tvShouldChange = NO;
_tfShouldChange = NO;
if ([_input isKindOfClass:[UITextField class]]) {
id<UITextFieldDelegate> del = [(UITextField *)_input delegate];
if ([del respondsToSelector:@selector(textField:shouldChangeCharactersInRange:replacementString:)]) {
_tfShouldChange = YES;
}
} else if ([_input isKindOfClass:[UITextView class]]) {
id<UITextViewDelegate> del = [(UITextView *)_input delegate];
if ([del respondsToSelector:@selector(textView:shouldChangeTextInRange:replacementText:)]) {
_tvShouldChange = YES;
}
}
}
}

// Call this for each button press
- (void)click {
[[UIDevice currentDevice] playInputClick];
}

// Call this when a button on the keyboard is tapped (other than return or backspace)
- (void)keyTapped:(UIButton *)button {
NSString *text = ???; // determine text for the button that was tapped

if ([_input respondsToSelector:@selector(shouldChangeTextInRange:replacementText:)]) {
if ([_input shouldChangeTextInRange:[_input selectedTextRange] replacementText:text]) {
[_input insertText:text];
}
} else if (_tfShouldChange) {
NSRange range = [(UITextField *)_input selectedRange];
if ([[(UITextField *)_input delegate] textField:(UITextField *)_input shouldChangeCharactersInRange:range replacementString:text]) {
[_input insertText:text];
}
} else if (_tvShouldChange) {
NSRange range = [(UITextView *)_input selectedRange];
if ([[(UITextView *)_input delegate] textView:(UITextView *)_input shouldChangeTextInRange:range replacementText:text]) {
[_input insertText:text];
}
} else {
[_input insertText:text];
}
}

// Used for a UITextField to handle the return key button
- (void)returnTapped:(UIButton *)button {
if ([_input isKindOfClass:[UITextField class]]) {
id<UITextFieldDelegate> del = [(UITextField *)_input delegate];
if ([del respondsToSelector:@selector(textFieldShouldReturn:)]) {
[del textFieldShouldReturn:(UITextField *)_input];
}
} else if ([_input isKindOfClass:[UITextView class]]) {
[_input insertText:@"\n"];
}
}

// Call this to dismiss the keyboard
- (void)dismissTapped:(UIButton *)button {
[(UIResponder *)_input resignFirstResponder];
}

// Call this for a delete/backspace key
- (void)backspaceTapped:(UIButton *)button {
if ([_input respondsToSelector:@selector(shouldChangeTextInRange:replacementText:)]) {
UITextRange *range = [_input selectedTextRange];
if ([range.start isEqual:range.end]) {
UITextPosition *newStart = [_input positionFromPosition:range.start inDirection:UITextLayoutDirectionLeft offset:1];
range = [_input textRangeFromPosition:newStart toPosition:range.end];
}
if ([_input shouldChangeTextInRange:range replacementText:@""]) {
[_input deleteBackward];
}
} else if (_tfShouldChange) {
NSRange range = [(UITextField *)_input selectedRange];
if (range.length == 0) {
if (range.location > 0) {
range.location--;
range.length = 1;
}
}
if ([[(UITextField *)_input delegate] textField:(UITextField *)_input shouldChangeCharactersInRange:range replacementString:@""]) {
[_input deleteBackward];
}
} else if (_tvShouldChange) {
NSRange range = [(UITextView *)_input selectedRange];
if (range.length == 0) {
if (range.location > 0) {
range.location--;
range.length = 1;
}
}
if ([[(UITextView *)_input delegate] textView:(UITextView *)_input shouldChangeTextInRange:range replacementText:@""]) {
[_input deleteBackward];
}
} else {
[_input deleteBackward];
}

[self updateShift];
}

@end

此類需要UITextField的類別方法：

@interface UITextField (CustomKeyboard)

- (NSRange)selectedRange;

@end

@implementation UITextField (CustomKeyboard)

- (NSRange)selectedRange {
UITextRange *tr = [self selectedTextRange];

NSInteger spos = [self offsetFromPosition:self.beginningOfDocument toPosition:tr.start];
NSInteger epos = [self offsetFromPosition:self.beginningOfDocument toPosition:tr.end];

return NSMakeRange(spos, epos - spos);
}

@end