touchdown、touchupinside、touchoutside などのボタンのイベントを管理することでこれを行うことができます。
その時点でボタンを押すと、0.2秒の遅延でタイマーが開始され、ボタンの touchup メソッドが起動するまで textDocumentProxy から最後の文字が削除されます。その後、タイマーを無効にする必要があります。
[self.btnDelete addTarget:self action:@selector(btnTocuhDown:) forControlEvents:UIControlEventTouchDown];
[self.btnDelete addTarget:self action:@selector(btnTouchUp:) forControlEvents:UIControlEventTouchUpInside];
[self.btnDelete addTarget:self action:@selector(btnTouchUp:) forControlEvents:UIControlEventTouchUpOutside];
-(無効) btnTocuhDown
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:0.2 target:self selector:@selector(kpTimerMethod:) userInfo:nil repeats:YES];
self.kpTimer = timer;
__weak typeof(self)weakSelf = self;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^(void){
if (timer == self.kpTimer) {
[weakSelf.kpTimer fire];
}
});
-(void)kpTimerMethod:(NSTimer *)timer
if (self.btnDelete.highlighted)
{
[self deleteLastCharacter];
}
else
{
[timer invalidate];
self.kpTimer = nil;
}
-(void)deleteLastCharacter
NSString *strInput = self.textDocumentProxy.documentContextBeforeInput;
if (strInput.length > 1)
NSString *coupleOfLastCharacters = [strInput substringWithRange:NSMakeRange(strInput.length-2, 2)];
if( [@"yo" caseInsensitiveCompare:coupleOfLastCharacters] == NSOrderedSame ) {
[self.textDocumentProxy deleteLastCharacter];
}
}
[self.textDocumentProxy deleteLastCharacter];
-(無効) btnTouchUp
[self.kpTimer invalidate];
self.kpTimer = nil;