ios-小知识点－自定义uislider

//左右轨的图片
    UIImage *stetchLeftTrack= [UIImage imageNamed:@"brightness_bar.png"];
    UIImage *stetchRightTrack = [UIImage imageNamed:@"brightness_bar.png"];
    //滑块图片
    UIImage *thumbImage = [UIImage imageNamed:@"mark.png"];

    UISlider *sliderA=[[UISlider alloc]initWithFrame:CGRectMake(30, 320, 257, 7)];
    sliderA.backgroundColor = [UIColor clearColor];
    sliderA.value=1.0;
    sliderA.minimumValue=0.7;
    sliderA.maximumValue=1.0;

    [sliderA setMinimumTrackImage:stetchLeftTrack forState:UIControlStateNormal];
    [sliderA setMaximumTrackImage:stetchRightTrack forState:UIControlStateNormal];
    //注意这里要加UIControlStateHightlighted的状态，否则当拖动滑块时滑块将变成原生的控件
    [sliderA setThumbImage:thumbImage forState:UIControlStateHighlighted];
    [sliderA setThumbImage:thumbImage forState:UIControlStateNormal];
    //滑块拖动时的事件
    [sliderA addTarget:self action:@selector(sliderValueChanged:) forControlEvents:UIControlEventValueChanged];
    //滑动拖动后的事件
    [sliderA addTarget:self action:@selector(sliderDragUp:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:sliderA];