ios学习笔记（三）UISlider与UISwitch控件
最后更新于：2022-04-01 09:50:43
1 首先我们还是创建一个Single View Application，然后打开MainStoryboard_iphone.storyboard,在IB中添加一个UISlider控件和一个Label，这个Label用来显示Slider的值。
选中新加的Slider控件，打开Attribute Inspector，修改属性值，设置最小值为0，最大值为100，当前值为0.5，并确保勾选上Continuous，如下图：
接着我们放上UISwitch控件，就是很像开关的那种控件，它只有两个状态：on和off，全都放上去效果就是这样的：
2.好了我们开始写代码喽：ViewController.h：
~~~
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController{
UILabel *sliderlabel;
UISwitch *leftSwitch;
UISwitch *rightSwitch;
}
@property (nonatomic,retain) IBOutlet UILabel *sliderlabel;
@property (nonatomic,retain) IBOutlet UISwitch *leftSwitch;
@property (nonatomic,retain) IBOutlet UISwitch *rightSwitch;
- (IBAction)sliderChanged:(id)sender;
- (IBAction)switchChanged:(id)sender;
@end
~~~
接着是实现 ViewController.m:
~~~
#import "ViewController.h"
@interface ViewController ()
@end
@implementation ViewController
@synthesize sliderlabel;
@synthesize leftSwitch;
@synthesize rightSwitch;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
} else {
return YES;
}
}
- (IBAction)sliderChanged:(id)sender{
UISlider *slider=(UISlider*)sender;
int progressAsInt=(int)(slider.value+0.5f);
NSString *newText=[[NSString alloc] initWithFormat:@"%d",progressAsInt];
sliderlabel.text=newText;
[newText release];
NSLog(@"%d",progressAsInt);
}
- (IBAction)switchChanged:(id)sender{
UISwitch *whichSwich=(UISwitch *)sender;
BOOL setting=whichSwich.isOn;
[leftSwitch setOn:setting animated:YES];
[rightSwitch setOn:setting animated:YES];
}
- (void)dealloc{
[sliderlabel release];
[leftSwitch release];
[rightSwitch release];
[super dealloc];
}
@end
~~~
3.剩下的就是连接操作和输出口：
将slider控件的value changed事件与sliderChanged方法连接在一起，将swich控件的value changed事件与swichChanged方法连接在一起，当然还要把lable控件和swich控件的输出与ViewController的相应控件接口连接在一起。
最终实现的效果如下面两张图：
