当Android中NumberPicker不只滚动(按加号或减号)时，如何从onValueChange获取NumberPicker实例的值 [英] How to get value of the NumberPicker instance from onValueChange when The NumberPicker not scrolling only(pressing plus or minus buttons) in Android

问题描述

我有一个NumberPicker实例，它可以按预期工作，但是当滚动停止或用户仅按增减按钮时，我需要从中获取值. 我应该得到的值显示在文本视图中.

I have a NumberPicker instance and it works as expected but I need to get value form it when scrolling stops Or when the user only press increments / decrements Button is pressed. the value that i should get it are displayed in the text view.

当滚动停止/变为空闲并正确显示时，我设法获得了该值(在onScrollChanged()侦听器中完成).

i managed to get the value when scrolling stops/ became idle and displayed correctly(this done in onScrollChanged() listener).

，但是当用户按下增量或减量按钮时，不会触发onScrollChanged()侦听器，并且如果我使用onValueChanged()侦听器，则文本会更新，但滚动变得非常缓慢和缓慢(由于value一直更新更改).

but the onScrollChanged() listener won't be fired when user press on increments or decrements buttons and if I use onValueChanged() listener the text updated but scrolling became very laggy and slow( as result of updating all the time when value changed).

所以我需要帮助，如何始终显示NumberPicker的值，而不会导致NumberPicker滚动的滞后或减慢.

So I need help how to display the value of NumberPicker all the time without causing lagging or slowing of NumberPicker scrolling.

代码如下:

    NumberPicker milisecoundsNumberPicker = (NumberPicker) findViewById(R.id.numberPicker);
    milisecNumberPicker.setFocusable(false);
    milisecNumberPicker.setFocusableInTouchMode(false);
    TextView textNumber = (TextView) findViewById(R.id.selectednum);



    milisecNumberPicker.setMaxValue(10);
    milisecNumberPicker.setMinValue(0);
    milisecNumberPicker.setWrapSelectorWheel(false);
    String[] nums = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10" };
    milisecNumberPicker.setDisplayedValues(nums);// array of numbers
    milisecNumberPicker.setOnScrollListener(new OnScrollListener() {
        @Override
        public void onScrollStateChange(NumberPicker view, int scrollState) {

            if (scrollState == OnScrollListener.SCROLL_STATE_IDLE
                    || scrollState == OnScrollListener.SCROLL_STATE_TOUCH_SCROLL) {
                view.getValue();

                textNumber.setText(view.getValue() + "");
 //this is ok no lagging but will not work on pressing increments and decrements buttons    
            }

        }
    }); 
// If I use this
    milisecNumberPicker.setOnValueChangedListener(new OnValueChangeListener() {
        @Override
        public void onValueChange(NumberPicker picker, int oldVal, int newVal) { 
                    // set Text value here causing lagging on scrolling                                                             
        }
    });

抱歉，格式不好，这是我的新手，但是任何人都可以帮助我解决这个问题.

Sorry bout bad formatting I'm new in this but can any one help me in this topic.

推荐答案

HI

import android.os.Handler;

......

milisecoundsNumberPicker.setOnValueChangedListener(new android.widget.NumberPicker.OnValueChangeListener() {
        @Override
        public void onValueChange(android.widget.NumberPicker picker, final int oldVal, final int newVal) {
            final Handler handler = new Handler();
            handler.postDelayed(new Runnable() {
                public void run() {
                    if (newVal == milisecoundsNumberPicker.getValue()) {
                        textNumber.setText(newVal + "");
                    }
                }
            }, 500);//set time 
        }
    });

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