blocks|key|3237343|text|‘s视图的center是一个属性，而不是一个方法。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3237344|你需要计算你想要放置它的实际位置。您可以通过设置视图的框架或设置其中心来执行此操作，后者在您的情况下会更简单。|3237345|您不需要说明是什么视图，然后就可以让imageView成为它的子视图。如果你把它放在一个叫做superview的东西里面，你可以这样做：|3237346|CGPoint+superCenter+=+CGPointMake(CGRectGetMidX([superview+bounds]),+CGRectGetMidY([superview+bounds]));
[imageView+setCenter:superCenter];|code-block|syntax|javascript|3237347|entityMap^0|5|6|0|0|I|9|1A|9|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|T|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|J|3|K|5|L|7|Z|8|@]|D|@]|E|$M|N]]|$1|O|3|-4|5|6|7|10|8|@]|D|@]|E|$]]]|P|$]]

UIView's <code>center</code> is a property, not a method. 

You need to calculate the actual location you want to put it in. You can do this by setting the frame of the view, or by setting its center, which is simpler in your case.

You don't say what view you then go make <code>imageView</code> a subview of. If you're putting it inside something called <code>superview</code>, you could do this:

<pre><code>CGPoint superCenter = CGPointMake(CGRectGetMidX([superview bounds]), CGRectGetMidY([superview bounds]));
[imageView setCenter:superCenter];
</code></pre>

blocks|key|299964|text|CGRect+r+=+thingToCenter.frame;
r.origin+=+parentView.bounds.origin;
r.origin.x+=+parentView.bounds.size.width+/+2++-+r.size.width+/+2;
r.origin.y+=+parentView.bounds.size.height+/+2++-+r.size.height+/+2+%2B+12;
thingToCenter.frame+=+r;|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|299965|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>CGRect r = thingToCenter.frame;
r.origin = parentView.bounds.origin;
r.origin.x = parentView.bounds.size.width / 2 - r.size.width / 2;
r.origin.y = parentView.bounds.size.height / 2 - r.size.height / 2 + 12;
thingToCenter.frame = r;
</code></pre>

blocks|key|299967|text|根据parentView的矩形的大小和原点在parentView中定位imageView。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|299968|给定一个名为parentView的父视图：|299969|float+parentRect+=+parentView.frame;
float+imageRect+=+imageView.frame;

imageRect.origin.x+=+(int)(parentView.origin.x+%2B+(parentRect.size.width+-+imageRect.size.width)+/+2);
imageRect.origin.y+=+(int)(parentView.origin.y+%2B+(parentRect.size.height-+imageRect.size.height)+/+2);
imageView.frame+=+imageRect;|code-block|syntax|javascript|299970|将原点转换为int可以确保居中的图像不会模糊(尽管它可能偏离中心的子像素量)。|299971|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|O|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Position the imageView in the parentView based on the size and origin of the parentView's rect.

Given a parent view named parentView:

<pre><code>float parentRect = parentView.frame;
float imageRect = imageView.frame;

imageRect.origin.x = (int)(parentView.origin.x + (parentRect.size.width - imageRect.size.width) / 2);
imageRect.origin.y = (int)(parentView.origin.y + (parentRect.size.height- imageRect.size.height) / 2);
imageView.frame = imageRect;
</code></pre>

Casting the origins to int ensures that your centered image is not blurry (though it may be off center by a subpixel amount).

blocks|key|3237402|text|查看：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3237403|https://developer.apple.com/documentation/coregraphics/cggeometry|offset|length|3237404|您可以执行以下操作：|3237405|CGPoint+center+=+CGPointMake(CGRectGetMidX(mainRect),+CGRectGetMidY(mainRect));|code-block|syntax|javascript|3237406|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|1T|0|0|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|U|8|@]|9|@$D|V|E|W|1|X]]|A|$]]|$1|F|3|G|5|6|7|Y|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|Z|8|@]|9|@]|A|$K|L]]|$1|M|3|-4|5|6|7|10|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|C]]]]

Looking at:

<a href="https://developer.apple.com/documentation/coregraphics/cggeometry" rel="nofollow noreferrer">https://developer.apple.com/documentation/coregraphics/cggeometry</a>

You can do:

<pre><code>CGPoint center = CGPointMake(CGRectGetMidX(mainRect), CGRectGetMidY(mainRect));
</code></pre>

blocks|key|297967|text|CGRect+CGRectIntegralCenteredInRect(CGRect+innerRect,+CGRect+outerRect)+{
++++CGFloat+originX+=+outerRect.origin.x+%2B+((outerRect.size.width+-+innerRect.size.width)+*+0.5f);
++++CGFloat+originY+=+outerRect.origin.y+%2B+((outerRect.size.height+-+innerRect.size.height)+*+0.5f);
++++return+CGRectIntegral(CGRectMake(originX,+originY,+innerRect.size.width,+innerRect.size.height));
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|297968|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>CGRect CGRectIntegralCenteredInRect(CGRect innerRect, CGRect outerRect) {
 CGFloat originX = outerRect.origin.x + ((outerRect.size.width - innerRect.size.width) * 0.5f);
 CGFloat originY = outerRect.origin.y + ((outerRect.size.height - innerRect.size.height) * 0.5f);
 return CGRectIntegral(CGRectMake(originX, originY, innerRect.size.width, innerRect.size.height));
}
</code></pre>

blocks|key|3237449|text|如果函数经常被调用，为了简单起见，您还可以使用此处所示的宏。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3237450|#define+Center(x)+CGPointMake(CGRectGetMidX(x),+CGRectGetMidY(x));|code-block|syntax|javascript|3237451|然后像这样使用它|3237452|CGPoint+myPoint+=+Center(myRect);|3237453|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

If the function is called frequently, you can also use macros as shown here for simplicity.

<pre><code>#define Center(x) CGPointMake(CGRectGetMidX(x), CGRectGetMidY(x));
</code></pre>

Then use it like

<pre><code>CGPoint myPoint = Center(myRect);
</code></pre>

blocks|key|3237455|text|对于Swift+4：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3237456|CGPoint+center+=+CGPoint(x:+buttonRect.midX,+y:+buttonRect.midY)|code-block|syntax|javascript|3237457|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

For Swift 4:

<pre><code>CGPoint center = CGPoint(x: buttonRect.midX, y: buttonRect.midY)
</code></pre>

blocks|key|300009|text|Swift+4|type|unstyled|depth|inlineStyleRanges|entityRanges|data|300010|let+center+=+CGPoint(x:+bounds.midX,+y:+bounds.midY)|code-block|syntax|javascript|300011|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Swift 4

<pre><code>let center = CGPoint(x: bounds.midX, y: bounds.midY)
</code></pre>

I have an image displaying in a CGRect. how do I center the rect in the view?

here's my code:

<pre><code>UIImage * image = [UIImage imageNamed:place.image];
CGRect rect = CGRectMake(10.0f, 90.0f, image.size.width, image.size.height);

UIImageView * imageView = [[UIImageView alloc] initWithFrame:rect];
[imageView setImage:image];
</code></pre>

I've tried imageView.center but to no effect.

thanks in advance.

centering a CGRect in a view

Swift

我有一个在CGRect中显示的图像。如何使矩形在视图中居中？下面是我的代码：UIImage * image = [UIImage imageNamed:place.image];CGRect rect = CGRectMake(10.0f, 90.0f, image.size.width, image.size.hei...

问使CGRect在视图中居中
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