http://www.itstrike.cn/Question/c51c60a2-4ea9-4902-8ef9-0f14d1fcba9b.html
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UITextView * view = [[UITextView alloc]init];
view.frame = CGRectMake(20, 30, [UIScreen mainScreen].bounds.size.width-40, [UIScreen mainScreen].bounds.size.height-30);
view.font= [UIFont systemFontOfSize:15];
view.delegate = self;
[self.view addSubview:view];
view.textContainer.maximumNumberOfLines = 2;
}
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
NSString *newText = [textView.text stringByReplacingCharactersInRange:range withString:text];
NSDictionary *textAttributes = @{NSFontAttributeName : textView.font};
CGFloat textWidth = CGRectGetWidth(UIEdgeInsetsInsetRect(textView.frame, textView.textContainerInset));
textWidth -= 2.0f * textView.textContainer.lineFragmentPadding;
CGRect boundingRect = [newText boundingRectWithSize:CGSizeMake(textWidth, 0)
options:NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading
attributes:textAttributes
context:nil];
NSUInteger numberOfLines = CGRectGetHeight(boundingRect) / textView.font.lineHeight;
return newText.length <= 500 && numberOfLines <= 2;
}
原文：http://www.cnblogs.com/yecong/p/7803140.html