开发中调整View的时候的经常会遇到frame和bounds，刚开始看的时候不是很清楚，不过看了一下官方文档，frame是确定视图在父视图中的位置，和本身的大小,bounds确定可以确定子视图在当前视图中的位置，还可以改变View的大小，如果bounds确定大小，那么View的视图优先选择的bounds中的宽高。Center的位置是相对于父坐标系中的定位。苹果官方给了一张图片供参考:
如果还不是很清晰，可以参考一下frame和bounds的中代码:
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-(CGRect)frame{
return
CGRectMake(
self
.frame.origin.x,
self
.frame.origin.y,
self
.frame.size.width,
self
.frame.size.height);
}
-(CGRect)bounds{
return
CGRectMake(0,0,
self
.frame.size.width,
self
.frame.size.height);
}
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当然为了更好的理解以上的概念，写个小Demo实战了一下，viewDidLoad将图片添加在View中，然后在图片上添加一个View:
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UIImageView *girlImageView=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@
"Girl.jpg"
]];
girlImageView.frame=CGRectMake(40, 40, 240, 300);
[
self
.view addSubview:girlImageView];
//添加到父视图中
NSLog
(@
"girlImageView frame:%@------girlImageView bounds:%@"
,
NSStringFromCGRect
(girlImageView.frame),
NSStringFromCGRect
(girlImageView.bounds));
UIView *childView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];
childView.backgroundColor = [UIColor yellowColor];
[girlImageView addSubview:childView];
NSLog
(@
"childView frame:%@-------childView bounds:%@"
,
NSStringFromCGRect
(childView.frame),
NSStringFromCGRect
(childView.bounds));
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具体效果如下:
输出结果:
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2015-04-03 11:50:00.326 MyContraint[1929:98282] girlImageView frame:{{40, 40}, {240, 300}}------girlImageView bounds:{{0, 0}, {240, 300}}
2015-04-03 11:50:00.327 MyContraint[1929:98282] childView frame:{{0, 0}, {100, 100}}-------childView bounds:{{0, 0}, {100, 100}}
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这个时候如果改变一下UIImageView的bounds，代码如下:
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UIImageView *girlImageView=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@
"Girl.jpg"
]];
girlImageView.frame=CGRectMake(40, 40, 240, 300);
//改变View中内部原点的位置，同样可以改变frame的宽高
[girlImageView setBounds:CGRectMake(-30, -30, 240, 230)];
[
self
.view addSubview:girlImageView];
//添加到父视图中
NSLog
(@
"girlImageView frame:%@------girlImageView bounds:%@"
,
NSStringFromCGRect
(girlImageView.frame),
NSStringFromCGRect
(girlImageView.bounds));
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图片效果:
打印效果如下:
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2015-04-03 11:57:06.738 MyContraint[2019:102665] girlImageView frame:{{40, 75}, {240, 230}}------girlImageView bounds:{{-30, -30}, {240, 230}}
2015-04-03 11:57:06.739 MyContraint[2019:102665] childView frame:{{0, 0}, {100, 100}}-------childView bounds:{{0, 0}, {100, 100}}
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通过以上的代码的演示，frame和bounds之间的关系应该很清晰了，如果有疑问，欢迎共同探讨~
