iOS学习(UI)知识点整理
一、关于UIButton的介绍
1)概念:UIButton 是一种常用的控件,通过点击触发相应的功能
2)UIButton 的几种常用的状态
1、UIControlStateNormal 正常状态
2、UIControlStateHighlighted 高亮状态
3、UIControlStateSelected 选中状态 -> 当button的selected设置成yes之后才能触发
3)UIButton常用的几种事件
1、UIControlEventTouchUpInside 按钮按下并抬起事件
2、UIControlEventTouchDown 按钮按下事件
3、UIControlEventTouchDownRepeat 按钮多次点击触发事件
4)UIButton 初始化实例代码
1 UIButton *button = [[UIButton alloc] init]; 2 button.frame = CGRectMake(20, 50, 50 , 50); 3 button.backgroundColor = [UIColor clearColor]; 4 [button setTitle:@"按钮1 正常状态" forState:UIControlStateNormal]; 5 [button setTitle:@"按钮1 高亮状态" forState:UIControlStateHighlighted]; 6 [button setTitle:@"按钮1 选中状态" forState:UIControlStateSelected]; 7 8 //按钮点击时触发事件 9 [button addTarget:self action:@selector(buttonTapped:) forControlEvents:UIControlEventTouchUpInside]; 10 //按钮按下后触发事件 11 [button addTarget:self action:@selector(buttonTappedDown:) forControlEvents:UIControlEventTouchDown]; 12 //按钮双击触发事件 13 [button addTarget:self action:@selector(buttonTappedDown:) forControlEvents:UIControlEventTouchDownRepeat]; 14 //设置按钮高亮状态下的字体颜色 15 [button setTitleColor:[UIColor lightGrayColor] forState:UIControlStateHighlighted]; 16 //button字体变为35号加粗的字体 17 button.titleLabel.font = [UIFont boldSystemFontOfSize:35]; 18 //设置圆角 19 button.layer.cornerRadius = 5.f; 20 //设置边框宽度 21 button.layer.borderWidth = 2.1; 22 //设置边框颜色 23 button.layer.borderColor = [UIColor lightGrayColor].CGColor; 24 //设置按钮背景图 25 UIImage *imageNormal = [UIImage imageNamed:@"camera"]; 26 //设置imageNormal为按钮的正常情况的图片 27 [button setImage:imageNormal forState:UIControlStateNormal]; 28 29 UIImage *imageHightLight = [UIImage imageNamed:@"camera2"]; 30 //设置imageHightLight为按钮的高亮情况的图片 31 [button setImage:imageHightLight forState:UIControlStateHighlighted]; 32 //当button设置了图片的时候 并且没有设置高亮状态下得图片,取消高亮状态, 默认是Yes 33 button.adjustsImageWhenHighlighted = YES; 34 [self.window addSubview:button];
5)防止按钮多次点击重复提交数据的实例代码
1 [button addTarget:self action:@selector(buttonTapped:) forControlEvents:UIControlEventTouchUpInside]; 3 - (void)buttonTapped:(UIButton *)button 4 { 5 //设置按钮不可点击 6 button.userInteractionEnabled = NO; 8 //延迟执行方法 防止按钮被快速点击或者不希望点击造成错误 9 [self performSelector:@selector(delayMethod:) withObject:button afterDelay:1]; 11 } 12 13 //延迟方法->设置按钮为可点击状态 14 - (void)delayMethod:(UIButton *)button 15 { 16 button.userInteractionEnabled = YES; 17 }
二、关于UIImageView的介绍
1)概念:UIImageView 是iOS中专门用于展示图片的控件
2)UIImageView 初始化 实例代码
1 UIImageView *imageView = [[UIImageView alloc] init]; 2 imageView.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.width); 3 imageView.backgroundColor = [UIColor whiteColor]; 4 imageView.center = self.view.center; 5 6 //tag设置控件的唯一标识,值不能重复 7 imageView.tag = 100; 8 9 //UIImageView的 clipsToBounds属性,设置为yes的时候超出部分,不予以显示 10 imageView.clipsToBounds = YES; 11 12 //读取一张图片 13 UIImage *image = [UIImage imageNamed:@"icon"]; 14 imageView.image = image; 15 16 //设置图片展示模式 17 imageView.contentMode = UIViewContentModeScaleAspectFill; 18 19 //打开imageview的用户交互 注:要实现图片点击事件此属性必须设置为YES 20 imageView.userInteractionEnabled = YES; 21 [self.view addSubview:imageView]; 22 23 //为UIImageView添加点击事件 24 UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imageViewTapped:)]; 25 [imageView addGestureRecognizer:tap];
3)UI_ImageView中常用的几种填充模式
1、UIViewContentModeScaleToFill 拉伸image使其充满UIImageView
2、UIViewContentModeScaleAspectFill 拉伸image使其不变形,并且充满UIImageView
3、UIViewContentModeScaleAspectFit 拉伸imgage使其不变形,并且完全显示在UIImageView中
4)UITapGestureRecognizer 除了可以给UI_ImageView添加点击方法外还可以给其他控件添加点击方法
如:UI_Lable、UI_View...等
5)iOS中获取图片的三种方法
方法一:
1 //把图片对象加载到内存中 2 UIImage *image1 = [UIImage imageNamed:@"camera"]; 3 CGSize size = image1.size; 4 NSLog(@"size.w %f size.h %f",size.width ,size.height); 5 //如果图片的格式是png,则后缀名可以省略,其他格式不能省略 6 UIImage *image2 = [UIImage imageNamed:@"icon.jpeg"];
方法二:
//使用场景:读取大图片,比较占内存的,需要及时释放的图片要用这种方法 //读取icon.jpeg NSString *imagePath3 = [[NSBundle mainBundle] pathForResource:@"icon" ofType:@"jpeg"]; UIImage *image3 = [[UIImage alloc] initWithContentsOfFile:imagePath3]; NSString *imagePath3_1 = [[NSBundle mainBundle] pathForResource:@"icon.jpeg" ofType:nil]; UIImage *image3_1 = [[UIImage alloc] initWithContentsOfFile:imagePath3_1];
方法三:
1 NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"icon" ofType:@"jpeg"]; 2 3 UIImage *image4 = [UIImage imageWithContentsOfFile:imagePath];