objective c - How to add UIbutton on UIview programmatically in ios using autolayouts -

i want add uibutton on uiview programmatically using autolayouts , tried code it's not working please me one

//adding uiview using autolayouts

uiview * myview; myview = [uiview new];     myview.translatesautoresizingmaskintoconstraints = no;     myview.backgroundcolor = [uicolor colorwithred:0.95 green:0.47 blue:0.48 alpha:1.0];     [self.view addsubview:myview];    nslayoutconstraint * constraint = [nslayoutconstraint constraintwithitem:myview attribute:nslayoutattributeleading relatedby:nslayoutrelationequal toitem:self.view attribute:nslayoutattributeleading multiplier:1.0f constant:30.0f];     [self.view addconstraint:constraint];      constraint = [nslayoutconstraint constraintwithitem:myview attribute:nslayoutattributetop relatedby:nslayoutrelationequal toitem:self.view attribute:nslayoutattributetop multiplier:1.0f constant:100.0f];     [self.view addconstraint:constraint];      constraint = [nslayoutconstraint constraintwithitem:myview attribute:nslayoutattributewidth relatedby:nslayoutrelationequal toitem: nil attribute:nslayoutattributenotanattribute multiplier:1.0f constant:100.0f];     [self.view addconstraint:constraint];      constraint = [nslayoutconstraint constraintwithitem:myview attribute:nslayoutattributeheight relatedby:nslayoutrelationequal toitem: nil attribute:nslayoutattributenotanattribute multiplier:1.0f constant:100.0f];     [self.view addconstraint:constraint]; 

adding button on uiview using autolayouts:-

mainbutton = [uibutton buttonwithtype:uibuttontyperoundedrect];     [mainbutton settitle:@"mainbutton" forstate:uicontrolstatenormal];     [mainbutton sizetofit];     mainbutton.backgroundcolor = [uicolor blackcolor];     mainbutton.translatesautoresizingmaskintoconstraints = no;     [self.view addsubview:mainbutton];   nslayoutconstraint *constraint = [nslayoutconstraint constraintwithitem:mainbutton attribute:nslayoutattributeleading relatedby:nslayoutrelationequal toitem:myview attribute:nslayoutattributeleading multiplier:1.0f constant:30.f];     [self.view addconstraint:constraint];      constraint = [nslayoutconstraint constraintwithitem:mainbutton attribute:nslayoutattributetop relatedby:nslayoutrelationequal toitem:myview attribute:nslayoutattributetop multiplier:1.0f constant:30.f];     [self.view addconstraint:constraint];  constraint = [nslayoutconstraint constraintwithitem:mainbutton attribute:nslayoutattributewidth relatedby:nslayoutrelationgreaterthanorequal toitem:nil attribute:nslayoutattributewidth multiplier:1.0f constant:20.f];     [self.view addconstraint:constraint];  constraint = [nslayoutconstraint constraintwithitem:mainbutton attribute:nslayoutattributeheight relatedby:nslayoutrelationgreaterthanorequal toitem:nil attribute:nslayoutattributeheight multiplier:1.0f constant:20.f];     [self.view addconstraint:constraint]; 

but button not adding on myview please me one

this working :

uiview *myview = [uiview new]; myview.translatesautoresizingmaskintoconstraints = no; myview.backgroundcolor = [uicolor colorwithred:0.95 green:0.47 blue:0.48 alpha:1.0]; [self.view addsubview:myview];  nslayoutconstraint * constraint = [nslayoutconstraint constraintwithitem:myview attribute:nslayoutattributeleading relatedby:nslayoutrelationequal toitem:self.view attribute:nslayoutattributeleading multiplier:1.0f constant:30.0f]; [self.view addconstraint:constraint];  constraint = [nslayoutconstraint constraintwithitem:myview attribute:nslayoutattributetop relatedby:nslayoutrelationequal toitem:self.view attribute:nslayoutattributetop multiplier:1.0f constant:100.0f]; [self.view addconstraint:constraint];  constraint = [nslayoutconstraint constraintwithitem:myview attribute:nslayoutattributewidth relatedby:nslayoutrelationequal toitem: nil attribute:nslayoutattributenotanattribute multiplier:1.0f constant:140.0f]; [self.view addconstraint:constraint];  constraint = [nslayoutconstraint constraintwithitem:myview attribute:nslayoutattributeheight relatedby:nslayoutrelationequal toitem: nil attribute:nslayoutattributenotanattribute multiplier:1.0f constant:100.0f]; [self.view addconstraint:constraint];  uibutton *mainbutton = [uibutton new];  mainbutton = [uibutton buttonwithtype:uibuttontyperoundedrect]; [mainbutton settitle:@"mainbutton" forstate:uicontrolstatenormal]; [mainbutton sizetofit]; mainbutton.backgroundcolor = [uicolor blackcolor]; mainbutton.translatesautoresizingmaskintoconstraints = no; [self.view addsubview:mainbutton];  nslayoutconstraint *constraint1 = [nslayoutconstraint constraintwithitem:mainbutton attribute:nslayoutattributeleading relatedby:nslayoutrelationequal toitem:myview attribute:nslayoutattributeleading multiplier:1.0f constant:30.f]; [self.view addconstraint:constraint1];  constraint1 = [nslayoutconstraint constraintwithitem:mainbutton attribute:nslayoutattributetop relatedby:nslayoutrelationequal toitem:myview attribute:nslayoutattributetop multiplier:1.0f constant:30.f]; [self.view addconstraint:constraint1];  constraint1 = [nslayoutconstraint constraintwithitem:mainbutton attribute:nslayoutattributewidth relatedby:nslayoutrelationgreaterthanorequal toitem:nil attribute:nslayoutattributewidth multiplier:1.0f constant:20.f]; [self.view addconstraint:constraint1];  constraint1 = [nslayoutconstraint constraintwithitem:mainbutton attribute:nslayoutattributeheight relatedby:nslayoutrelationgreaterthanorequal toitem:nil attribute:nslayoutattributeheight multiplier:1.0f constant:20.f]; [self.view addconstraint:constraint1];