如何垂直实现自动调整大小的UITextView？

Question

First look at the screenshot:

second press the return button, the screenshot for your reference:

after four times click

return

button, the height of text field will not be higher any more.

now here is the question: how can I implement the function of textfield? and what about the background Image behind the text Field , should auto resize too? if there are any solution, let me know! thanks very much----

Answer 1

Make it UITextView not a text field, track the text changes at shouldChangeTextInRange of the textView delegate.

In this method calculate the number of lines (textView.contentSize.height/textView.font.lineHeight), compare it with the previous value to decide whether you need to proceed or just return. If the number of lines is changed, check whether the textView is already displaying the maximum number of lines (that must be 3 on the image) and based on the results you will change the textView , it's superview and a button frames (you can also make it animated easily) and probably scroll the text to the change region with scrollRangeToVisible .