UILabel 根据文字长度自动调整

-(void)autoSetLabWidthForLab:(UILabel *)lab
{
   // NSLog(@"t-> %@",lab.text);
    lab.layer.masksToBounds=YES;
    lab.layer.cornerRadius=11;
    lab.numberOfLines=0;
    lab.textAlignment=UITextAlignmentCenter;
    lab.font=[UIFont fontWithName:@"Arial" size:14.0];
    lab.textColor=[UIColor whiteColor];
    UIFont *font = [UIFont fontWithName:@"Arial" size:14.0];
    CGSize size = CGSizeMake(400,30);
    CGSize labelsize = [lab.text sizeWithFont:font constrainedToSize:size lineBreakMode:NSLineBreakByWordWrapping];
    CGRect r=lab.frame;
    if (labelsize.width<16) {
        r.size.width=2*labelsize.width+10;
    }else{
        r.size.width=labelsize.width+10;
    }
    [lab setFrame:r];
}