objective c - How to align UIImageView to the centre of the view controller? -

objective c - How to align UIImageView to the centre of the view controller? -

i want imageview appear centre @ bottom,i added imageview imageview in view controller.the result imageview appearing @ bottom not @ centre, can 1 suggest wrong in code?

-(void)viewwillappear:(bool)animated { uiimageview *imgview=[[uiimageview alloc]init]; [imgview settranslatesautoresizingmaskintoconstraints:no]; uiimageview *mspimgvw=[[uiimageview alloc]init]; [mspimgvw settranslatesautoresizingmaskintoconstraints:no]; mspimgvw.image=[uiimage imagenamed:@"msplogo.jpg"]; [self.imgview addsubview:mspimgvw]; [self.view addsubview:imgview]; cgfloat bottom=0; [imgview addconstraint:[nslayoutconstraint constraintwithitem:mspimgvw attribute:nslayoutattributebottom relatedby:nslayoutrelationequal toitem:imgview attribute:nslayoutattributebottom multiplier:1 constant:bottom-40]]; [imgview addconstraint:[nslayoutconstraint constraintwithitem:mspimgvw attribute:nslayoutattributecenterx relatedby:nslayoutrelationequal toitem:imgview attribute:nslayoutattributecenterx multiplier:1.0 constant:bottom-40]]; [self.view addconstraints:[nslayoutconstraint constraintswithvisualformat:@"h:|[imgview]|" options:0 metrics: 0 views:dicviews]]; [self.view addconstraints:[nslayoutconstraint constraintswithvisualformat:@"v:|[imgview]|" options:0 metrics: 0 views:dicviews]]; }

i want image appear centre of view controller.what alter in code?

here go:

[self.view addconstraint:[nslayoutconstraint constraintwithitem:imageview attribute:nslayoutattributecenterx relatedby:nslayoutrelationequal toitem:self.view attribute:nslayoutattributecenterx multiplier:1.f constant:0.f]]; [self.view addconstraint:[nslayoutconstraint constraintwithitem:imageview attribute:nslayoutattributebottom relatedby:nslayoutrelationequal toitem:self.view attribute:nslayoutattributebottom multiplier:1.f constant:0.f]];

objective-c iphone autolayout