Question

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
    NSString *substring = textView.text;
    substring = (text.length == 0 && range.length == 1) ?
    [substring substringToIndex: substring.length-1] : [substring stringByAppendingString: text];

    CGSize size = [substring sizeWithFont:textView.font
                        constrainedToSize:CGSizeMake(textView.frame.size.width, 200.0)];

    CGFloat height = MAX(size.height, firstHeight);

    if(height != lastHeight)
    {
        CGFloat y = height - lastHeight;
        CHANGE_HEIGHT(textView, height);
        lastHeight = height;
    }   
    return YES;
}

问题是 sizeWithFont:constrainedToSize: 给了我错误的高度。例如，如果文字“Hello \n” sizeWithFont将不计算“\n”，所以“Hello”和“Hello \n”文字处于相同的高度。

任何需要的帮助将不胜感激！

Answer 1

不相关，但获得substring的方式忽略了文本修改的范围。

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
    NSString *textToMeasure = [textView.text stringByReplacingCharactersInRange:range withString:text];
    if ([textToMeasure hasSuffix:@"\n"]) {
        textToMeasure = [NSString stringWithFormat:@"%@-", textView.text];
    ...
}

sizeWithFont：constrainedToSize：不计算＆＃34; \ n＆＃34;在NSString中

1 个答案: