iOS5新控件UIStepper应用示例

// Create a label to show the value in the stepper
label = [[UILabel alloc] initWithFrame:CGRectMake(10, 20, 100, 30)];
[label setTextColor:[UIColor whiteColor]];
[label setBackgroundColor:[UIColor clearColor]];
[label setTextAlignment:UITextAlignmentLeft];
[label setText: @"Quantity:"];
[[self view] addSubview:label];

// Frame defines location, size values are ignored
UIStepper *stepper = [[UIStepper alloc] initWithFrame:CGRectMake(120, 20, 0, 0)];

// Set action target and action for a particular value changed event
[stepper addTarget:self action:@selector(stepperPressed:) forControlEvents:UIControlEventValueChanged];

// Set min and max
[stepper setMinimumValue:0];
[stepper setMaximumValue:99];

// Value wraps around from minimum to maximum
[stepper setWraps:YES];

// If continuos (default), changes are sent for each change in stepper,
// otherwise, change event occurs once user lets up on button
[stepper setContinuous:NO];

// To change the increment value for each step
// (default is 1)
[stepper setStepValue:10];