获取UILabel上最后一个字符串的位置。获取文字长度和高度，自动换行

 //行的高度。
 -(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
    NewNotificationCell *cell = (NewNotificationCell *)[self tableView:tableView cellForRowAtIndexPath:indexPath];
     cell.myLabel.text = [self.dataArray objectAtIndex:indexPath.row];
     labelSize = [cell.myLabel.text sizeWithFont:[UIFont fontWithName:@"Arial" size:] constrainedToSize:CGSizeMake(cell.myLabel.frame.size.width, ) lineBreakMode:UILineBreakModeWordWrap];
     cell.myLabel.lineBreakMode = UILineBreakModeWordWrap;
     cell.myLabel.numberOfLines = ;
     [cell.myLabel setFont:[UIFont fontWithName:@"Arial" size:]];
     cell.myLabel.frame = CGRectMake(, , labelSize.width, labelSize.height);

     return labelSize.height+;
 }

     //自动换行。
     cell.myLabel.text = [self.dataArray objectAtIndex:indexPath.row];
     labelSize = [cell.myLabel.text sizeWithFont:[UIFont fontWithName:@"Arial" size:] constrainedToSize:CGSizeMake(cell.myLabel.frame.size.width, ) lineBreakMode:UILineBreakModeWordWrap];
     cell.myLabel.lineBreakMode = UILineBreakModeWordWrap;
     cell.myLabel.numberOfLines = ;
     [cell.myLabel setFont:[UIFont fontWithName:@"Arial" size:]];
     cell.myLabel.frame = CGRectMake(, , labelSize.width, labelSize.height);

     //获取文字长度和高度。
     CGSize fontSize =[cell.myLabel.text sizeWithFont:cell.myLabel.font
                                     forWidth:cell.myLabel.frame.size.width
                                lineBreakMode:UILineBreakModeWordWrap];
     NSLog(@"文字长度=%f",fontSize.width);

     //获取UILabel上最后一个字符串的位置。
     CGPoint lastPoint;
     CGSize sz = [cell.myLabel.text sizeWithFont:cell.myLabel.font constrainedToSize:CGSizeMake(MAXFLOAT, )];

     CGSize linesSz = [cell.myLabel.text sizeWithFont:cell.myLabel.font constrainedToSize:CGSizeMake(cell.myLabel.frame.size.width, MAXFLOAT) lineBreakMode:UILineBreakModeWordWrap];
     if(sz.width <= linesSz.width) //判断是否折行
     {
         lastPoint = CGPointMake(cell.myLabel.frame.origin.x + sz.width, cell.myLabel.frame.origin.y);
     }
     else
     {
         lastPoint = CGPointMake(cell.myLabel.frame.origin.x + (int)sz.width % (int)linesSz.width,linesSz.height - sz.height);
     }
     NSLog(@"====%f",lastPoint.x);

     [cell.myButton setTitle:@"查看" forState:UIControlStateNormal];
     [cell.myButton setBackgroundImage:[UIImage imageNamed:@"button.png"] forState:UIControlStateNormal];
     if ([cell.myButton.titleLabel.text isEqualToString:@"查看"]) {
         cell.myButton.frame = CGRectMake(lastPoint.x+, labelSize.height-, , );
     }
     [cell.timeButton setTitle:@"今天" forState:UIControlStateNormal];
     cell.timeButton.frame = CGRectMake(, labelSize.height+, , );
     return cell;
 }