IOS basic 2: Use of UIStepper (Counter)

IOS basic 2: Use of UIStepper (Counter)
This is a control that appears only after iOS5. It has been used in projects. Therefore, UIStepper is a control similar to UISwitch, but there is a plus sign and a minus sign on both sides of the control.The control looks similar to UISwitch and consists of two buttons. A button is "+" and a button is "-" to jointly control the increase or decrease of the same value.
In iOS5, a digital input control UIStepper is added, which can be used to incrementally input the number. UIStepper inherits from UIControl. Its main event is UIControlEventValueChanged. This event is triggered whenever its value changes.

It mainly has the following attributes:

The value currently expressed. The default value is 0.0 minimumValue. The default value is 0.0. The default value is 100.0, by default, some attributes and methods in the 1.0 document are as follows: Configure Stepper
• continuous AttributeBOOL type. The default value is YES. YES indicates that the ValueChange event will be sent immediately when the user interaction ends. NO indicates that the ValueChange event will be sent only when the user interaction ends.
• autorepeat AttributeBOOL type. The default value is YES. If YES, it means to press and hold the plus sign or minus sign to keep changing the number.
• wraps AttributeBOOL type. The default value is NO. If YES, when the value is greater than maximumValue, the value is changed to the value of minimumValue. If the value is smaller than minimumValue, the value is changed to the value of maximum. If it is set to NO, the value will not exceed the maximum and minimum values.
• minimumValue AttributeDouble TypeThe default value is 0 and the minimum value. If the value is greater than or equal to maximumValue, an NSInvalidArgumentExcepti message is returned.On exception
• maximumValue AttributeDouble TypeThe default value is 100, which is the maximum value of Stepper. If it is set to be smaller than or equal to minimumValue,NSInvalidArgumentExceptiOn exception
• stepValue AttributeThe default value of the Double type is 1, and the increment or number of steps of Stepper (for example, if stepValue is 10, add 10 at the click, and then subtract 10). The value must be greater than 0. Otherwise,NSInvalidArgumentExceptiOn exception
• Access Stepper Value
• value AttributeThe default value of the Double type is 0, and the maximum value is maximumValue and the minimum value is minimumValue. When the value changes, the UIControlValueEventChangEd to target
• Customized appearance
• tintColor Attribute UIColor type. The default value is nil. It is added in iOS 6.
  • -(UIImage*) BackgroundImageForState :( UIControlState) state
  • What status do I use for background images? added in iOS 6

  • UIControlState has six enumerated Variables

    
          
          
    
           
           
    enum {
          
          

    
          
          
    
           
           
    UIControlStateNormal = 0, normal
     
            
     
             
    UIControlStateHighlighteD = 1 <0, click within the scope, but it is not easy
     
              
     
               
    UIControlStateDisabled = 1 <1, when disabled
     
                
     
                 
    UIControlStateSelected = 1 <2, click it, and the loose is usually the status in which the button is pressed and sunken.
     
                  
     
                   
    UIControlStateApplicatioN = 0x00FF0000, additional status when used by the application
     
                    
     
                     
    UIControlStateReserved = 0xFF000000 internal framework used
     
                      
     
                       
    };
     
                      
     
                    
     
                  
     
                
     
              
     
            
          
          

  • -(Void) setBackgroundImage :( UIImage*) ImageForState :( UIControlState) state
  • The best picture is scalableNew in iOS 6
  • 
    
  • -(UIImage*) DecrementImageForState :( UIControlState) state
  • New in iOS 6
  • -(Void) setDecrementImage :( UIImage*) ImageForState :( UIControlState) state
  • New in iOS 6
  • Image of The minus sign button
  • 
    
  • -(UIImage*) IncrementImageForState :( UIControlState) state
  • New in iOS 6
  • -(Void) setIncrementImage :( UIImage*) ImageForState :( UIControlState) state
  • New in iOS 6
  • Image with the plus sign
  • 
    
  • -(UIImage*) DividerImageForLeftSegmeNtState :( UIControlState) leftStateRightSegmentState :( UIControlState) rightState
  • LeftState is the status of the button on the left, and rightState is the status of the button on the right.
  • Change the widget image when two buttons are in different States.
  • -(Void) setDividerImage :( UIImage*) ImageForLeftSegmentState :( UIControlState) leftStateRightSegmentState :( UIControlState) rightState
  • New in iOS 6
    Example: testStepper. stepValue = 10; testStepper. minimumValue = 0; testStepper. maximumValue = 55; testStepper. value = 10; testStepper. tintColor = [UIColor redColor]; testStepper. wraps = YES; it is always added at the beginning, then the value changes to 20 30 40 50 55 it is always reduced at the beginning, then the value changes to 0When the upper or lower limit is reached and wraps is not set to YES, the corresponding plus or minus button will be disable

    An interesting feature of this control is that when you press the "+" "-" button, the number of the control value is changed according to the length of the hold-down time. The longer the hold-down time, the faster the value changes. You can set a value range for UIStepper, for example, 0-99.
    
    The following is the UIStepper application sample code:

    01	// Create a label to show the value in the stepper

    02	label = [[UILabel alloc] initWithFrame:CGRectMake(10, 20, 100, 30)];

    03	[label setTextColor:[UIColor whiteColor]];

    04	[label setBackgroundColor:[UIColor clearColor]];

    05	[label setTextAlignment:UITextAlignmentLeft];

    06	[label setText: @"Quantity:"];

    07	[[self view] addSubview:label];

    08

    09	// Frame defines location, size values are ignored

    10	UIStepper *stepper = [[UIStepper alloc] initWithFrame:CGRectMake(120, 20, 0, 0)];

    11

    12	// Set action target and action for a particular value changed event

    13	[stepper addTarget:self action:@selector(stepperPressed:) forControlEvents:UIControlEventValueChanged];

    14

    15	// Set min and max

    16	[stepper setMinimumValue:0];

    17	[stepper setMaximumValue:99];

    18

    19	// Value wraps around from minimum to maximum

    20	[stepper setWraps:YES];

    21

    22	// If continuos (default), changes are sent for each change in stepper,

    23	// otherwise, change event occurs once user lets up on button

    24	[stepper setContinuous:NO];

    25

    26	// To change the increment value for each step

    27	// (default is 1)

    28	[stepper setStepValue:10];