objective c - Reposition label after apply transform iOS -

i've uilabel below center of uiview margin of 20 pixels.

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uiview center

uiviewcenter + 20

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 self.tablenamelabel.center = cgpointmake(self.tableview.origin.x + self.tableview.frame.size.width / 2, self.tableview.origin.y + self.tableview.frame.size.height / 2 + (ktablenamemargin/ 2.f)); 

when rotate uiview 90º degrees want recalculate position of uilabel, uilabel can stay in same place, below center same margin.

the problem when rotation applied, uilabel goes position. example, when apply 90º label goes right. specific reason why happens? know this:

warning: if transform property not identity transform, value of property undefined , therefore should ignored.

any ideia how can resolved this, uilabel can stay down center positioned?

instead of setting , calculating centre why don't use auto-layouting? in auto-layouting can align centre of label centre of parent view. remove need of repositioning label whenever transformation applied on parent view.

now if rotate parent view 90 degree label rotated 90 degree. avoid have rotate label 270 degrees shown below

-(void)rotateby90 {     self.parentview.transform = cgaffinetransformmakerotation(m_pi_2); // 90 degress     self.label.transform = cgaffinetransformmakerotation(m_pi + m_pi_2); //270 degress }