UIStepper可以连续增加或减少一个数值。控件的外观是两个水平并排的按钮构成,一个显示为“+”,一个显示为“-”。
该控件的一个有趣的特征是当用户按住“+”,“-”按钮时,根据按住的时间长度,空间值的数字也以不同的数字改变。按住的时间越长,数值改变的越快。可以为UIStepper设定一个数值范围,比如0-99. 它的显示效果如下:
1. 属性说明
value: 当前所表示的值,默认为0.0;
minimumValue: 最小可以表示的值,默认0.0;
maximumValue: 最大可以表示的值,默认100.0;
stepValue: 每次递增或递减的值,默认为1.0;
2.如何判断加("+")减("-")
(1)通过设置一个 double* previousValue; *// *用来记录Stepper.value*的上一次值
(2)在对想操作的对象进行操作后,将Stepper.value = 0
#pragma mark - 设置UIStepper - (void)createUIStepper{UIStepper * stepperButton = [[UIStepper alloc]initWithFrame:CGRectMake(225, 500, 30, 10)]; [stepperButton addTarget:self action:@selector(controlStepperValue:) forControlEvents:UIControlEventValueChanged]; stepperButton.maximumValue = 100.0; stepperButton.minimumValue = 0.0; stepperButton.value = INITUISTEPPERVALUE; stepperButton.stepValue = 1.0; stepperButton.continuous = YES; stepperButton.wraps = NO; stepperButton.autorepeat = YES; [self.view addSubview:stepperButton]; [stepperButton release];
}
- (void)controlStepperValue:(UIStepper *)stepper{if (_segment.selectedSegmentIndex == 0) { if (stepper.value > previousValue) { CGRect redRect = _redView.frame; redRect.size.height += 5; _redView.frame = redRect; } else {
CGRect redRect = _redView.frame; redRect.size.height -= 5; _redView.frame = redRect; } previousValue = stepper.value; }else{ if (stepper.value > previousValue) { CGRect redRect = _greenView.frame; redRect.size.height += 5; _greenView.frame = redRect; } else {
CGRect redRect = _greenView.frame; redRect.size.height -= 5; _greenView.frame = redRect; } previousValue = stepper.value; }
}
3.基本用法整理
初始化控件
UIStepper * step = [[UIStepper alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];
@property(nonatomic,getter=isContinuous) BOOL continuous;
@property(nonatomic) BOOL autorepeat;
@property(nonatomic) BOOL wraps;
@property(nonatomic) double value;
@property(nonatomic) double minimumValue;//默认为0 @property(nonatomic) double maximumValue; //默认为100
@property(nonatomic) double stepValue;
@property(nonatomic,retain) UIColor *tintColor;
- (void)setBackgroundImage:(UIImage*)image forState:(UIControlState)state;
- (UIImage*)backgroundImageForState:(UIControlState)state;
- (void)setDividerImage:(UIImage*)image forLeftSegmentState:(UIControlState)leftState rightSegmentState:(UIControlState)rightState;
- (UIImage*)dividerImageForLeftSegmentState:(UIControlState)state rightSegmentState:(UIControlState)state;
- (void)setIncrementImage:(UIImage *)image forState:(UIControlState)state; - (UIImage *)incrementImageForState:(UIControlState)state;
- (void)setDecrementImage:(UIImage *)image forState:(UIControlState)state; - (UIImage *)decrementImageForState:(UIControlState)state;