UISlider的使用方式

	UISlider *slider = [[UISlider alloc] initWithFrame:CGRectMake(0, 0, 200, 20)];

	slider.minimumValue = 0;

	slider.maximumValue = 100;

	slider.value = 50;

	[slider addTarget:self action:@selector(updateValue:) forControlEvents:UIControlEventValueChanged];

	[self.view addSubview:slider];