Nativescript log slider value on update

问题

I am new to Nativescript. Yesterday I asked how to create a slider and read those values. This question was answered however now I want to log those values once the value of the slider has been updated.

I made a sample project that prints the value once I press a button. Now I want to print the value each time the value of the slider changes. I looked at the slider documentation and the propertyChange event documentation but can't get this to work.

Here is the link to the playground I am trying this in: Playground

Can anybody tell me how I'd properly bind my slider to the observable and how I'd capture the event that fires once the value updates?

Thanks in advance!

回答1:

You could attach to the valueChange listener via code-behind.

exports.onSliderLoaded = function (args) {
  const slider = args.object;

  slider.on("valueChange", (args) => { 
    console.log(args.value);
  })
}

Where onSliderLoaded is used via the loaded event for your slider

<Slider value="{{ slider }}" loaded="onSliderLoaded" />

Full Playground demo demonstrating the above can be found here

来源：https://stackoverflow.com/questions/49800467/nativescript-log-slider-value-on-update