添加下面代碼就可以了

-(void)addMySlider{   
        //左右軌的圖片 
        UIImage *stetchLeftTrack= [UIImage imageNamed:@"light_off_on.png"]; 
        UIImage *stetchRightTrack = [UIImage imageNamed:@"light_off_back.png"]; 
        //滑塊圖片 
        UIImage *thumbImage = [UIImage imageNamed:@"light_round.png"]; 
        UISlider *sliderA=[[UISlider alloc]initWithFrame:CGRectMake(30, 320, 257, 7)]; 
        sliderA.backgroundColor = [UIColor clearColor]; 
        sliderA.value=0.5; 
        sliderA.minimumValue=0.0; 
        sliderA.maximumValue=1.0; 
        [sliderA setMinimumTrackImage:stetchLeftTrack forState:UIControlStateNormal]; 
        [sliderA setMaximumTrackImage:stetchRightTrack forState:UIControlStateNormal]; 
        //注意這里要加UIControlStateHightlighted的狀態，否則當拖動滑塊時滑塊將變成原生的控件 
        [sliderA setThumbImage:thumbImage forState:UIControlStateHighlighted]; 
        [sliderA setThumbImage:thumbImage forState:UIControlStateNormal]; 
        //滑塊拖動時的事件 
        [sliderA addTarget:self action:@selector(sliderValueChanged) forControlEvents:UIControlEventValueChanged]; 
        //滑動拖動后的事件 
        [sliderA addTarget:self action:@selector(sliderDragUp) forControlEvents:UIControlEventTouchUpInside]; 
        [self.view addSubview:sliderA];   
    } 
    -(void)sliderDragUp{         
        NSLog(@"sliderDragUp"); 
    }     
    -(void)sliderValueChanged{        
        NSLog(@"sliderValueChanged");     
    }