UI笔记：UILabel、UIButton和UITextField

#import "AppDelegate.h"@interface AppDelegate (){    UIImageView *flagImageView;}@end@implementation AppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];    self.window.backgroundColor = [UIColor colorWithRed:48/255.0 green:152/255.0 blue:244/255.0 alpha:1.0];    //按钮    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];    button.frame = CGRectMake((375-120)/2, 40, 120, 40);    [button setBackgroundImage:[UIImage imageNamed:@"smallHeader"] forState:0];    //圆角    button.layer.cornerRadius  = 20/2;    button.layer.masksToBounds = YES;    //tittle    [button setTitle:@"按钮" forState:0];    //tittle字体    button.titleLabel.font = [UIFont systemFontOfSize:20];    //设置自然状态下的颜色RGB    [button setTitleColor:[UIColor colorWithRed:2/255.0 green:23/255.0 blue:52/255.0 alpha:1.0] forState:0];    //UIControlEventTouchDown按在按钮状态，此状态下执行方法buttonActionTouchDown:    [button addTarget:self action:@selector(buttonActionTouchDown:) forControlEvents:UIControlEventTouchDown];    //不可编辑状态    [button setTitle:@"不可编辑状态" forState:UIControlStateDisabled];//    button.enabled = NO;    //UIControlEventTouchUpInside按下放开过程，此过程执行方法buttonActionTouchUpInside:    [button addTarget:self action:@selector(buttonActionTouchUpInside:) forControlEvents:UIControlEventTouchUpInside];    //建立图片视图，初始化图片header（png格式）    flagImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"header"]];    //设置视图大小和位置    flagImageView.frame = CGRectMake((375-82)/2, 120, 82, 82);    //视图圆角    flagImageView.layer.cornerRadius = 40/2;    flagImageView.layer.masksToBounds = YES;    //隐藏视图    flagImageView.hidden = YES;    //设置视图动画时间    flagImageView.animationDuration = 0.8;    //播放的内容是两张图片    flagImageView.animationImages = @[[UIImage imageNamed:@"header"],[UIImage imageNamed:@"kongjiantouxiang"]];    //播放重复次数为最大浮点数。    flagImageView.animationRepeatCount = FLT_MAX;    UILabel *label2 = [[UILabel alloc] initWithFrame:CGRectZero];    NSString *string = @"狂风呼啸、暴雨倾泻";    label2.text = string;    label2.font = [UIFont systemFontOfSize:24];//    label2.font = [UIFont fontWithName:<#(NSString *)#> size:<#(CGFloat)#>];    CGSize size = [string sizeWithAttributes:@{NSFontAttributeName:label2.font}];    label2.frame = CGRectMake(50, 220, size.width, size.height);    UILabel *label = [[UILabel alloc] initWithFrame:CGRectZero];    string = @"狂风呼啸、暴雨倾泻、惊涛骇浪，顷刻间，山洪暴发、山体滑坡、泥石流、房屋倒塌、江河满溢、道路中断、村庄被淹、农田被毁......这是台风“苏迪罗”肆虐温州南部县市的灾难景象。";    label.text = string;    //不限制label的行数    label.numberOfLines = 0;    //省略符合位置    label.lineBreakMode = NSLineBreakByTruncatingMiddle;    //label.text的大小；    CGRect rect = [label.text boundingRectWithSize:CGSizeMake([UIScreen mainScreen].bounds.size.width, 300) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:label.font} context:nil];    //颜色    label.backgroundColor = [UIColor yellowColor];    //设置frame    label.frame = CGRectMake(0, 260, rect.size.width, rect.size.height);    //添加控件    [self.window addSubview:label2];    [self.window addSubview:label];    [self.window addSubview:flagImageView];    [self.window addSubview:button];    [self.window makeKeyAndVisible];    return YES;}-(void) buttonActionTouchDown:(UIButton *)sender {    flagImageView.hidden = NO;    [flagImageView startAnimating];}-(void) buttonActionTouchUpInside:(UIButton *) sender {    flagImageView.hidden = YES;    [flagImageView stopAnimating];    sender.enabled = NO;}