我在 iOS 中使用 UITextView,并且想获得下一个输入文本将开始另一个新行的时刻/点。
我怎样才能得到这个?
-----已编辑-----
----经过长时间的研究,我发现下面是可以的,但看起来有点复杂。
//limit text within text box
NSString *originalStr = textView.text;
textView.text = [textView.text stringByAppendingString:text];
CGFloat lineHeight = textView.font.lineHeight;
int currentLines = textView.contentSize.height / lineHeight;
int maxLines = textView.frame.size.height/lineHeight;
if (currentLines > maxLines) {
NSString * firstHalfString = [originalStr substringToIndex:range.location];
NSString * secondHalfString = [originalStr substringFromIndex: range.location];
textView.text = [NSString stringWithFormat: @"%@%@%@",
firstHalfString,
text,
secondHalfString];
int timeout = 0;
while (true) {
timeout =50;
textView.text = [textView.text substringToIndex:(textView.text.length -1)];
int newCurrentLines = textView.contentSize.height / lineHeight;
if ((newCurrentLines == maxLines) || (timeout > 50))
break;
}
textView.selectedRange = range;
return false;
} else {
textView.text = originalStr;
textView.selectedRange = range;
return true;
}