Hi I am trying to add UIViews programmatically using Auto Layout. 
Here my main requirement is that I want to set the firstView(i.e myView1) trailing space to "30" and I want to set the second view (i.e myView2) to 30 distance from first view like image below. 
For this I have written some code (using visual format and constraint with item format) but this is not working.
Code:
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    UIView *myView1 = [[UIView alloc] init];
    myView1.backgroundColor = [UIColor redColor];
    myView1.translatesAutoresizingMaskIntoConstraints = NO;  
    [self.view addSubview:myView1];
    UIView *myView2 = [[UIView alloc] init];
    myView2.backgroundColor = [UIColor orangeColor];
    myView2.translatesAutoresizingMaskIntoConstraints = NO;  
    [self.view addSubview:myView2];
    [self.view addConstraints:[NSLayoutConstraint
                               constraintsWithVisualFormat:@"V:|-[myView1(==50)]-50-|"
                               options:0
                               metrics:nil
                               views:NSDictionaryOfVariableBindings(myView1)]];
    [self.view addConstraints:[NSLayoutConstraint
                               constraintsWithVisualFormat:@"V:|-[myView2(==50)]-50-|"
                               options:0
                               metrics:nil
                               views:NSDictionaryOfVariableBindings(myView2)]];
//Constraints with item formate
            NSLayoutConstraint *constraint = [NSLayoutConstraint constraintWithItem:myView1 attribute:NSLayoutAttributeTrailing relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeTrailing multiplier:1.0f constant:-30.f];
            [self.view addConstraint:constraint];
            constraint = [NSLayoutConstraint constraintWithItem:myView1 attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem: nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1.0f constant:50.0f];
            [self.view addConstraint:constraint];
           NSLayoutConstraint*constraint1 = [NSLayoutConstraint constraintWithItem:myView2 attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:myView1 attribute:NSLayoutAttributeTrailing multiplier:1.0f constant:-30.f];
          [self.view addConstraint:constraint1];
           constraint1 = [NSLayoutConstraint constraintWithItem:myView2 attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem: nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1.0f constant:50.0f];
          [self.view addConstraint:constraint1];
//Constraints with visual formate
  [self.view addConstraints:[NSLayoutConstraint
                               constraintsWithVisualFormat:@"H:|-[myView1(==50)]-20-[myView(==50)]-30-|"
                               options:0
                               metrics:nil
                               views:NSDictionaryOfVariableBindings(myView1,myView2)]];
}

 
     
    
