UIView基础

#import "ViewController.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.    UIView *myview=[[UIView alloc]init];    myview.frame=CGRectMake(40, 20, 200, 200);    myview.backgroundColor=[UIColor blueColor];    [self.view addSubview:myview];        NSLog(@"x:%f,t:%f,w:%f,h:%f.",myview.frame.origin.x,myview.frame.origin.y          ,myview.frame.size.width,myview.frame.size.height);    NSLog(@"x:%f,t:%f,w:%f,h:%f.",myview.bounds.origin.x,myview.bounds.origin.y          ,myview.bounds.size.width,myview.bounds.size.height);    NSLog(@"x:%f,t:%f.",myview.center.x,myview.center.y);        //父式图    UIView *superview=myview.superview;    superview.backgroundColor=[UIColor greenColor];        UIView *view2=[[UIView alloc]init];    view2.frame=CGRectMake(10, 20, 20, 20);    view2.backgroundColor=[UIColor yellowColor];    view2.tag=2;    [myview addSubview:view2];        UIView *view3=[[UIView alloc]init];    view3.frame=CGRectMake(5, 30, 50, 40);    view3.tag=3;    view3.backgroundColor=[UIColor purpleColor];    [myview addSubview:view3];        //将子视图加入数组中进行遍历    NSArray *mysubviews=myview.subviews;    for (UIView *view in mysubviews)    {        if (view.tag==2) {            view.backgroundColor=[UIColor greenColor];        }        view3.backgroundColor=[UIColor yellowColor];    }        //使用tag进行选择 viewwithtag    UIView *sub2view=[myview viewWithTag:3];    sub2view.backgroundColor=[UIColor grayColor];        //交换两个层式图    [myview exchangeSubviewAtIndex:2 withSubviewAtIndex:3];    UIView *view4=[[UIView alloc]init];    view4.frame=CGRectMake(10, 20, 20, 20);    view4.backgroundColor=[UIColor blackColor];    //[myview insertSubview:view4 atIndex:2];   // [myview insertSubview:view4 belowSubview:view2];    //[myview bringSubviewToFront:view2];    [myview sendSubviewToBack:view3];        UIView *backview=[[UIView alloc]init];    backview.frame=CGRectMake([UIScreen mainScreen].bounds.size.width/2-25, 400, 50, 50);    backview.tag=1001;    backview.backgroundColor=[UIColor orangeColor];    [self.view addSubview:backview];    //准许子视图自适应    backview.autoresizesSubviews=YES;        UIView  *topview=[[UIView alloc]init];    topview.frame=CGRectMake(10, 10, 30, 30);    topview.backgroundColor=[UIColor yellowColor];    //子视图自适应    topview.autoresizingMask=UIViewAutoresizingFlexibleLeftMargin;    /* 跟随那一边进行变化    UIViewAutoresizingFlexibleLeftMargin;    UIViewAutoresizingFlexibleHeight;    UIViewAutoresizingFlexibleTopMargin;    */    [backview addSubview:topview];            //button    UIButton *btn=[UIButton buttonWithType:UIButtonTypeSystem];    btn.frame=CGRectMake(10, 550, 355, 30);    btn.backgroundColor=[UIColor blackColor];    [btn addTarget:self action:@selector(btnclick) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:btn];            }- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}//button点击事件-(void)btnclick{    UIView *view=[self.view viewWithTag:1001];    view.frame=CGRectMake(view.frame.origin.x-5, view.frame.origin.y-5, view.frame.size.width+10, view.frame.size.height+10);}@end