如何设置乘数为的UIImageView [英] How to set multiplier for the UIImageView
本文介绍了如何设置乘数为的UIImageView的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有一个形象的宽度= 189，高度= 41，所以我定义2约束这种的UIImageView 是这样的：
的NSArray * constraint_V = [NSLayoutConstraint constraintsWithVisualFormat：@V：[标题（41）]选项：0的指标：无意见：viewsDictionary];
[imgVwLogo addConstraints：constraint_V];NSArray的* constraint_H = [NSLayoutConstraint constraintsWithVisualFormat：@H：[标题（189）]选项：0的指标：无意见：viewsDictionary];
[imgVwLogo addConstraints：constraint_H];
它看起来对iPhone 4S好，但是当涉及到iPhone 6加我觉得的UIImageView 应该有点增加，因为图像看起来垂直缩水的高度。
也许添加乘数可以是溶液。但我不知道该如何选择乘数因子为我的元素。我将它设置为高度/宽度
NSLayoutConstraint * imgtitlecon_Aspect_Ratio = [NSLayoutConstraint
constraintWithItem：imgVwLogo
属性：NSLayoutAttributeHeight
relatedBy：NSLayoutRelationEqual
toItem：imgVwLogo
属性：NSLayoutAttributeHeight
事半功倍：一百八十九分之四十一
恒：0.0];
[imgVwLogo addConstraint：imgtitlecon_Aspect_Ratio];
但是这使得该的UIImageView 完全消失，即使是在4S。我怎样才能解决这个问题？
更新的
// ------------------------标题图像---------- ---------------------------------- NSArray的* constraint_V = [NSLayoutConstraint constraintsWithVisualFormat：@V：[标题（41）]选项：0的指标：无意见：viewsDictionary];
[imgVwLogo addConstraints：constraint_V];NSArray的* constraint_H = [NSLayoutConstraint constraintsWithVisualFormat：@H：[标题（189）]选项：0的指标：无意见：viewsDictionary];
[imgVwLogo addConstraints：constraint_H];
//水平居中
NSLayoutConstraint * centerXConstraintimgTitle =
[NSLayoutConstraint constraintWithItem：imgVwLogo
属性：NSLayoutAttributeCenterX
relatedBy：NSLayoutRelationEqual
toItem：self.view
属性：NSLayoutAttributeCenterX
事半功倍：1.0
恒：0.0];
[self.view addConstraint：centerXConstraintimgTitle];
NSLayoutConstraint * imgtitlecon_Aspect_Ratio = [NSLayoutConstraint
constraintWithItem：imgVwLogo
属性：NSLayoutAttributeHeight
relatedBy：NSLayoutRelationEqual
toItem：imgVwLogo
属性：NSLayoutAttributeHeight
乘数：（41.0f / 189.0f）
恒：0.0];
[imgVwLogo addConstraint：imgtitlecon_Aspect_Ratio];
NSArray的* Titleconstraint_POS_H = [NSLayoutConstraint constraintsWithVisualFormat：@H：| -titleVspace- [标题] -titleVspace- |选项：0指标：指标的观点：viewsDictionary];
[self.view addConstraints：Titleconstraint_POS_H];// ------------------------标题图像---------------------- --------------------------------------
最后我调整我的所有元素
的NSArray * btncon_POS_V = [NSLayoutConstraint constraintsWithVisualFormat:@\"V:|-50-[Title]-0-[vwgap]-0-[lblFirst]-0-[lblSecond]-20-[textusername]-10-[txtpassword]-20-[btnLogin]-0-[vwgapCopy]-0-[copyrightlbl]\"选项：0的指标：无意见：viewsDictionary];[self.view addConstraints：btncon_POS_V];
解决方案
如果你只是想设置从code宽高比，那么你只需要改变你的code一件小事情。在这里，它去。
[imgVwLogo addConstraint：[NSLayoutConstraint
constraintWithItem：imgVwLogo
属性：NSLayoutAttributeHeight
relatedBy：NSLayoutRelationEqual
toItem：imgVwLogo
属性：NSLayoutAttributeWidth
乘数：（41.0f / 189.0f）
恒：0.0];
编辑1：根据问题编辑答案会像下面code。
编辑2：请在故事板设计时改变568.0f价值的self.view高度值
[imgVwLogo addConstraint：[NSLayoutConstraint
constraintWithItem：imgVwLogo
属性：NSLayoutAttributeHeight
relatedBy：NSLayoutRelationEqual
toItem：imgVwLogo
属性：NSLayoutAttributeWidth
乘数：（41.0f / 189.0f）
恒：0.0];
[self.view addConstraint：[NSLayoutConstraint
constraintWithItem：imgVwLogo
属性：NSLayoutAttributeWidth
relatedBy：NSLayoutRelationEqual
toItem：self.view
属性：NSLayoutAttributeHeight
乘数：（189.0f / 568.0f）
恒：0.0];
[self.view addConstraint：[NSLayoutConstraint
constraintWithItem：imgVwLogo
属性：NSLayoutAttributeCenterX
relatedBy：NSLayoutRelationEqual
toItem：self.view
属性：NSLayoutAttributeCenterX
事半功倍：1.0F
恒：0.0];
[self.view addConstraint：[NSLayoutConstraint
constraintWithItem：imgVwLogo
属性：NSLayoutAttributeTop
relatedBy：NSLayoutRelationEqual
toItem：self.view
属性：NSLayoutAttributeTop
事半功倍：1.0F
常量：50.0f]];
I have an image whose width = 189, height = 41, so I defined 2 constraints for this UIImageView like this:
NSArray *constraint_V=[NSLayoutConstraint constraintsWithVisualFormat:@"V:[Title(41)]" options:0 metrics:nil views:viewsDictionary];
[imgVwLogo addConstraints:constraint_V];
NSArray *constraint_H=[NSLayoutConstraint constraintsWithVisualFormat:@"H:[Title(189)]" options:0 metrics:nil views:viewsDictionary];
[imgVwLogo addConstraints:constraint_H];
It looks good on iPhone 4s, but when it comes to iPhone 6 plus I feel the height of the UIImageview should be a bit increased, because the image looks shrunk vertically.
Maybe adding a multiplier could be the solution. But I don't know how to select the multiplier factor for my elements. I set it as height/width
NSLayoutConstraint *imgtitlecon_Aspect_Ratio =[NSLayoutConstraint
constraintWithItem:imgVwLogo
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:imgVwLogo
attribute:NSLayoutAttributeHeight
multiplier:41/189
constant:0.0f];
[imgVwLogo addConstraint:imgtitlecon_Aspect_Ratio];
but this makes that UIImageView disappear entirely even on the 4s. How can I solve this problem?
UPDATE
//------------------------ Title image --------------------------------------------
NSArray *constraint_V=[NSLayoutConstraint constraintsWithVisualFormat:@"V: [Title(41)]" options:0 metrics:nil views:viewsDictionary];
[imgVwLogo addConstraints:constraint_V];
NSArray *constraint_H=[NSLayoutConstraint constraintsWithVisualFormat:@"H:[Title(189)]" options:0 metrics:nil views:viewsDictionary];
[imgVwLogo addConstraints:constraint_H];
// Center Horizontally
NSLayoutConstraint *centerXConstraintimgTitle =
[NSLayoutConstraint constraintWithItem:imgVwLogo
attribute:NSLayoutAttributeCenterX
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeCenterX
multiplier:1.0
constant:0.0];
[self.view addConstraint:centerXConstraintimgTitle];
NSLayoutConstraint *imgtitlecon_Aspect_Ratio =[NSLayoutConstraint
constraintWithItem:imgVwLogo
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:imgVwLogo
attribute:NSLayoutAttributeHeight
multiplier:(41.0f/189.0f)
constant:0.0f];
[imgVwLogo addConstraint:imgtitlecon_Aspect_Ratio];
NSArray *Titleconstraint_POS_H=[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-titleVspace-[Title]-titleVspace-|" options:0 metrics:metrics views:viewsDictionary];
[self.view addConstraints:Titleconstraint_POS_H];
//------------------------ Title image ------------------------------------------------------------
and finally I align my all elements
NSArray *btncon_POS_V=[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-50-[Title]-0-[vwgap]-0-[lblFirst]-0-[lblSecond]-20-[textusername]-10-[txtpassword]-20-[btnLogin]-0-[vwgapCopy]-0-[copyrightlbl]" options:0 metrics:nil views:viewsDictionary];
[self.view addConstraints:btncon_POS_V];
解决方案
If you just want to set aspect ratio from code then you just need to change a small thing in your code. Here it goes.
[imgVwLogo addConstraint:[NSLayoutConstraint
constraintWithItem:imgVwLogo
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:imgVwLogo
attribute:NSLayoutAttributeWidth
multiplier:(41.0f/189.0f)
constant:0.0f]];
EDIT 1: according to question edit the answer will be like below code. EDIT 2: please change the 568.0f value to the value of the self.view height at the time of designing in storyboard.
[imgVwLogo addConstraint:[NSLayoutConstraint
constraintWithItem:imgVwLogo
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:imgVwLogo
attribute:NSLayoutAttributeWidth
multiplier:(41.0f/189.0f)
constant:0.0f]];
[self.view addConstraint:[NSLayoutConstraint
constraintWithItem:imgVwLogo
attribute:NSLayoutAttributeWidth
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeHeight
multiplier:(189.0f/568.0f)
constant:0.0f]];
[self.view addConstraint:[NSLayoutConstraint
constraintWithItem:imgVwLogo
attribute:NSLayoutAttributeCenterX
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeCenterX
multiplier:1.0f
constant:0.0f]];
[self.view addConstraint:[NSLayoutConstraint
constraintWithItem:imgVwLogo
attribute:NSLayoutAttributeTop
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeTop
multiplier:1.0f
constant:50.0f]];
这篇关于如何设置乘数为的UIImageView的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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