How to change font size in a textview?

I am making an application were user can read a detail or text and user can also be able to change the font size as per there requirement?

i hd tried using the following code but it's not working

-(IBAction)textSizeAction:(id)sender
{
    [self开发者_如何学Python setText:[self text] withSize:[sender floatValue]];        
}

so please suggest me some tutorial?

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You try with setFont method...

[urTextView setFont:[UIFont fontWithName:@"urFont/Helvetica" size:[sender floatValue]]];

//add Your font type