UITextView autoscroll to last line

问题:

When writing in a UITextView more text than can fit entirely inside it, the text will scroll up and the cursor will often place itself one or two lines above the view's bottom line. This is a bit frustrating as I want my application to make good use of the entire height of the text view.

Basically what I want is to configure the UITextView to write up to it's lowest part and not use it just for scrolling.

I've seen some similar questions here, here and here. However I've not seen a proper solution yet.

Thanks

回答1:

I've a slightly different implementation (I want to disable scrolling), but I also had to stop the cursor jumping out of my UITextView. To do this, I implemented a null scrollRectToVisible in my UITextView subclass. Like this:

- (void)scrollRectToVisible:(CGRect)rect animated:(BOOL)animated
{
// do nothing. This fixes the cursor jumping above the field defect.
}

回答2:

excellent solution is in subclass UITextView add lines

-(void) setContentOffset:(CGPoint)contentOffset {
    [self setContentInset:UIEdgeInsetsZero];
    [super setContentOffset:contentOffset];
}

It's work!

回答3:

use this

NSRange myRange=NSMakeRange(outPutTextView.text.length, 0);

[outPutTextView scrollRangeToVisible:myRange];

回答4:

if I understand right, you can use

[textView setScrollEnabled:NO];

to disable scrolling. what about not to type when the cursor reached the lower margin... maybe it is not good solution but you can add some threshold value(maximum characters in the [textView text]) and return NO in

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text

delegate method of UITextView if [[textView text] length] > maxCharacters.

回答5:

I find seem the property 'contentOffset' also can be use ...

回答6:

I've got the last line by setframe :

1. You can setframe to about a line height
2. When you are editing, in - (BOOL)textView:shouldChangeTextInRange:replacementText:,use scrollRangeToVisible:,the argument is selectedRange
3. When you end edit, setframe to the original size