宏定义的布局约束

 *自适应向布局约束的转化关闭
 */
#define PREPCONSTRAINTS(VIEW) [VIEW setTranslatesAutoresizingMaskIntoConstraints:NO]
#define CONSTRAIN(PARENT, VIEW, FORMAT) [PARENT addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:(FORMAT) options:0 metrics:nil views:NSDictionaryOfVariableBindings(VIEW)]]
#define CONSTRAIN_VIEWS(PARENT, FORMAT, VIEWBINDINGS) [PARENT addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:(FORMAT) options:0 metrics:nil views:VIEWBINDINGS]]

// Stretch across axis
#define STRETCH_VIEW_H(PARENT, VIEW) CONSTRAIN(PARENT, VIEW, @"H:|["#VIEW"(>=0)]|")
#define STRETCH_VIEW_V(PARENT, VIEW) CONSTRAIN(PARENT, VIEW, @"V:|["#VIEW"(>=0)]|")
#define STRETCH_VIEW(PARENT, VIEW) {STRETCH_VIEW_H(PARENT, VIEW); STRETCH_VIEW_V(PARENT, VIEW);}

// Center along axis 沿中心轴
/*
 *与父视图中心轴水平方向对齐
 */
#define CENTER_VIEW_H(PARENT, VIEW) [PARENT addConstraint:[NSLayoutConstraint constraintWithItem:VIEW attribute: NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:PARENT attribute:NSLayoutAttributeCenterX multiplier:1.0f constant:0.0f]]
/*
 *与父视图中心轴垂直方向对齐
 */
#define CENTER_VIEW_V(PARENT, VIEW) [PARENT addConstraint:[NSLayoutConstraint constraintWithItem:VIEW attribute: NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:PARENT attribute:NSLayoutAttributeCenterY multiplier:1.0f constant:0.0f]]
/*
 *以父视图的中心点为视图中心
 */
#define CENTER_VIEW(PARENT, VIEW) {CENTER_VIEW_H(PARENT, VIEW); CENTER_VIEW_V(PARENT, VIEW);}
/*
 *据里父视图的中心点Y方向的距离
 */
#define CENTER_VIEW_V_CONSTANT(PARENT, VIEW, CONSTANT) [PARENT addConstraint:[NSLayoutConstraint constraintWithItem:VIEW attribute: NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:PARENT attribute:NSLayoutAttributeCenterY multiplier:1.0f constant:CONSTANT]]

// Align to parent 与父视图对齐
/*
 *和父视图的左边对齐
 */
#define ALIGN_VIEW_LEFT(PARENT, VIEW) [PARENT addConstraint:[NSLayoutConstraint constraintWithItem:VIEW attribute: NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual toItem:PARENT attribute:NSLayoutAttributeLeft multiplier:1.0f constant:0.0f]]
/*
 *和父视图的右边对齐
 */
#define ALIGN_VIEW_RIGHT(PARENT, VIEW) [PARENT addConstraint:[NSLayoutConstraint constraintWithItem:VIEW attribute: NSLayoutAttributeRight relatedBy:NSLayoutRelationEqual toItem:PARENT attribute:NSLayoutAttributeRight multiplier:1.0f constant:0.0f]]
/*
 *和父视图的顶部对齐
 */
#define ALIGN_VIEW_TOP(PARENT, VIEW) [PARENT addConstraint:[NSLayoutConstraint constraintWithItem:VIEW attribute: NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:PARENT attribute:NSLayoutAttributeTop multiplier:1.0f constant:0.0f]]
/*
 *和父视图的底部对齐
 */
#define ALIGN_VIEW_BOTTOM(PARENT, VIEW) [PARENT addConstraint:[NSLayoutConstraint constraintWithItem:VIEW attribute: NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:PARENT attribute:NSLayoutAttributeBottom multiplier:1.0f constant:0.0f]]
/*
 *和父视图的右边距恒定不变
 */
#define ALIGN_VIEW_LEFT_CONSTANT(PARENT, VIEW, CONSTANT) [PARENT addConstraint:[NSLayoutConstraint constraintWithItem:VIEW attribute: NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual toItem:PARENT attribute:NSLayoutAttributeLeft multiplier:1.0f constant:CONSTANT]]
/*
 *和父视图的左边距恒定不变
 */
#define ALIGN_VIEW_RIGHT_CONSTANT(PARENT, VIEW, CONSTANT) [PARENT addConstraint:[NSLayoutConstraint constraintWithItem:VIEW attribute: NSLayoutAttributeRight relatedBy:NSLayoutRelationEqual toItem:PARENT attribute:NSLayoutAttributeRight multiplier:1.0f constant:CONSTANT]]
/*
 *和父视图的顶部距离恒定不变
 */
#define ALIGN_VIEW_TOP_CONSTANT(PARENT, VIEW, CONSTANT) [PARENT addConstraint:[NSLayoutConstraint constraintWithItem:VIEW attribute: NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:PARENT attribute:NSLayoutAttributeTop multiplier:1.0f constant:CONSTANT]]
/*
 *和父视图的底部距离恒定不变
 */
#define ALIGN_VIEW_BOTTOM_CONSTANT(PARENT, VIEW, CONSTANT) [PARENT addConstraint:[NSLayoutConstraint constraintWithItem:VIEW attribute: NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:PARENT attribute:NSLayoutAttributeBottom multiplier:1.0f constant:CONSTANT]]

// Set Size 设置大小
#define CONSTRAIN_WIDTH(VIEW, WIDTH) CONSTRAIN(VIEW, VIEW, @"H:["#VIEW"(=="#WIDTH")]")
#define CONSTRAIN_HEIGHT(VIEW, HEIGHT) CONSTRAIN(VIEW, VIEW, @"V:["#VIEW"(=="#HEIGHT")]")
#define CONSTRAIN_SIZE(VIEW, HEIGHT, WIDTH) {CONSTRAIN_WIDTH(VIEW, WIDTH); CONSTRAIN_HEIGHT(VIEW, HEIGHT);}

// Set Aspect
#define CONSTRAIN_ASPECT(VIEW, ASPECT) [VIEW addConstraint:[NSLayoutConstraint constraintWithItem:VIEW attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:VIEW attribute:NSLayoutAttributeHeight multiplier:(ASPECT) constant:0.0f]]