textField输入文本不为空与输入文本为空的判断

textField输入文本不为空与输入文本为空的判断

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range
replacementString:(NSString *)string
{
UIButton *btn = (UIButton *)[self.navigationController.navigationBar
viewWithTag:301];
if ((textField.text.length >
1 && string.length ==
0) ||( string.length !=
0)) {
[btn setUserInteractionEnabled:YES];
[btn setHighlighted:NO];
return
YES;
}
else {
[btn setUserInteractionEnabled:NO];
[btn setHighlighted:YES];
}
return
YES;
}

记录一下。。