Multiple DCSliders sending different control values (Xcode)

问题

This question may be very specific, but I'm new to all this and really need some help.

I'm building an iPhone synth app. I am using DCSliders an DCKnobs (they look nicer than the standard UISliders).

https://github.com/domesticcatsoftware/DCControls#readme

I am also working with libpd (a Pure Data library) so the audio DSP is handled by an embedded Pure Data patch.

https://gitorious.org/pdlib

I have got multiple DCSliders and DCKnobs in my interface. I am able to send control values from the sliders/knobs to Pure Data by making a class the delegate of the DCSlider...

- (void)loadView {
  [super loadView];
  self.mySlider = [[[DCSlider alloc] initWithDelegate:self] autorelease];
  self.mySlider.frame = CGRectMake(10.0, 10.0, 20.0, 120.0);

  [self.view addSubview:self.mySlider];
}

Then I implement a method to send control values to a receiver in Pure Data...

- (void)controlValueDidChange:(float)value sender:(id)sender {  
    [PdBase sendFloat:value toReceiver:@"beatvol"];
}

This all works ok.

The problem is that all of the sliders are sending the same control values.

How do I get each of the DCSliders to send independent control values to different receivers in Pure Data?

回答1:

You need to assign a tag to your sliders. Then in controlValueDidChange: you need to get that tag and do your actions according to the tags:

- (void)loadView 
{
    [super loadView];
    mySlider = [[[DCSlider alloc] initWithDelegate:self] autorelease];
    mySlider.frame = CGRectMake(10.0, 10.0, 20.0, 120.0);
    mySlider.tag = 0;
    [self.view addSubview: mySlider];
}
- (void)controlValueDidChange:(float)value sender:(id)sender 
{  
    DCSlider * slider = (DCSlider *)sender;

    switch (slider.tag) 
    {
        case 0: 
        { 
            [PdBase sendFloat:value toReceiver:@"beatvol"];
        }
            break;
        case 1: 
        { 
            /*  do something for the 2nd slider  */;
        }
            break;
    }        
}

来源：https://stackoverflow.com/questions/6869168/multiple-dcsliders-sending-different-control-values-xcode

标签

ios

xcode

audio

slider