检查 UITextView 中的文本是否由于自动换行而转到新行 [英] Check if text in UITextView went to new line due to word wrap

问题描述

如何检查 UITextView 中的文本是否由于自动换行而转到下一行?

How can I check if the text in a UITextView went to the next line due to word wrap?

我目前有代码来检查用户是否输入了新行(从键盘).

I currently have code to check if the user enters a new line (from the keyboard).

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text;
{
    if ( [text isEqualToString:@"\n"] ) {
        ...
    }
    return YES;
}

推荐答案

您可以使用 UITextView 的 contentSize.height 属性来确定您的 textview 有多高".然后，您可以除以 lineHeight 来计算行数.@nacho4d 提供了这行漂亮的代码来做到这一点:

You can use the contentSize.height property of UITextView to determine how 'tall' your textview is. You can then divide by the lineHeight to figure out the number of lines. @nacho4d provided this nifty line of code that does just that:

int numLines = textView.contentSize.height/textView.font.lineHeight;

有关更多信息，请参阅此问题:如何在uitextview中读取行数

Refer to this question for more info: How to read number of lines in uitextview

因此，您可以在 -textViewDidChange: 中执行类似操作，以检查行更改.

So you could do something like this inside -textViewDidChange: in order to check for a line change.

int numLines = textView.contentSize.height / textView.font.lineHeight; 
if (numLines != numLinesInTextView){
    numLinesInTextView = numLines;//numLinesInTextView is an instance variable
    //then do whatever you need to do on line change
}

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