標籤:android
在電商類app的購物車頁面,經常會有這樣的需求:長按“+”按鈕或者“-”按鈕時,購物車中的商品數量連續的增加或減少。
本例的目的就是為了實現這個效果。預覽圖:
1.自訂Button.
/** * 長按連續響應的Button * Created by admin on 15-6-1. */public class LongClickButton extends Button { /** * 長按連續響應的監聽,長按時將會多次調用該介面中的方法直到長按結束 */ private LongClickRepeatListener repeatListener; /** * 間隔時間(ms) */ private long intervalTime; private MyHandler handler; public LongClickButton(Context context) { super(context); init(); } public LongClickButton(Context context, AttributeSet attrs) { super(context, attrs); init(); } public LongClickButton(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } /** * 初始化監聽 */ private void init() { handler = new MyHandler(this); setOnLongClickListener(new OnLongClickListener() { @Override public boolean onLongClick(View v) { new Thread(new LongClickThread()).start(); return true; } }); } /** * 長按時,該線程將會啟動 */ private class LongClickThread implements Runnable { private int num; @Override public void run() { while (LongClickButton.this.isPressed()) { num++; if (num % 5 == 0) { handler.sendEmptyMessage(1); } SystemClock.sleep(intervalTime / 5); } } } /** * 通過handler,使監聽的事件響應在主線程中進行 */ private static class MyHandler extends Handler { private WeakReference<LongClickButton> ref; MyHandler(LongClickButton button) { ref = new WeakReference<>(button); } @Override public void handleMessage(Message msg) { super.handleMessage(msg); LongClickButton button = ref.get(); if (button != null && button.repeatListener != null) { button.repeatListener.repeatAction(); } } } /** * 設定長按連續響應的監聽和間隔時間,長按時將會多次調用該介面中的方法直到長按結束 * * @param listener 監聽 * @param intervalTime 間隔時間(ms) */ public void setLongClickRepeatListener(LongClickRepeatListener listener, long intervalTime) { this.repeatListener = listener; this.intervalTime = intervalTime; } /** * 設定長按連續響應的監聽(使用預設間隔時間100ms),長按時將會多次調用該介面中的方法直到長按結束 * * @param listener 監聽 */ public void setLongClickRepeatListener(LongClickRepeatListener listener) { setLongClickRepeatListener(listener, 100); } public interface LongClickRepeatListener { void repeatAction(); }}2.在Activity中調用:
LongClickButton buttonSub = (LongClickButton) findViewById(R.id.long_click_button1); LongClickButton buttonAdd = (LongClickButton) findViewById(R.id.long_click_button2); final TextView numberTV = (TextView) findViewById(R.id.main_number); //連續減 buttonSub.setLongClickRepeatListener(new LongClickButton.LongClickRepeatListener() { @Override public void repeatAction() { numberTV.setText(String.valueOf(Integer.parseInt(numberTV.getText().toString()) - 1)); } }, 50); //連續加 buttonAdd.setLongClickRepeatListener(new LongClickButton.LongClickRepeatListener() { @Override public void repeatAction() { numberTV.setText(String.valueOf(Integer.parseInt(numberTV.getText().toString()) + 1)); } }, 50); //減1 buttonSub.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { numberTV.setText(String.valueOf(Integer.parseInt(numberTV.getText().toString()) - 1)); } }); //加1 buttonAdd.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { numberTV.setText(String.valueOf(Integer.parseInt(numberTV.getText().toString()) + 1)); } });
Android:長按連續響應的Button