public boolean onKeyDown(int keyCode, KeyEvent event):
　　public boolean onKeyUp(int keyCode, KeyEvent event):
　　public boolean onKeyLongPress(int keyCode, KeyEvent event):

@Override
　public boolean onKeyDown(int keyCode, KeyEvent event) {
　case KeyEvent.KEYCODE_VOLUME_DOWN:
　case KeyEvent.KEYCODE_VOLUME_UP:
　if (mCameraAppView.getVisibility() != View.VISIBLE) {
　return false;
　}
　Log.v(TAG,"onKeyDown event.getRepeatCount() "+event.getRepeatCount());
　if (event.getRepeatCount() == 0) {
　event.startTracking();
　return true;
　}
　return true;
　}
　return super.onKeyDown(keyCode, event);
　}
　如果一直按着不放，通过打 log 可以看到
　onKeyDown event.getRepeatCount() 0
　onKeyDown event.getRepeatCount() 1
　onKeyDown event.getRepeatCount() 2
　onKeyDown event.getRepeatCount() 3
　onKeyDown event.getRepeatCount() 4
　onKeyDown event.getRepeatCount() 5
　onKeyDown event.getRepeatCount() 6
　onKeyDown event.getRepeatCount() 7
　onKeyDown event.getRepeatCount() 8
　onKeyDown event.getRepeatCount() 9
　onKeyDown event.getRepeatCount() 10
　onKeyDown event.getRepeatCount() 11
　onKeyDown event.getRepeatCount() 12
　……

@Override
　public boolean onKeyLongPress(int keyCode, KeyEvent event) {
　Log.v(TAG,"key long pressed keyCode = "+keyCode);
　switch (keyCode) {
　case KeyEvent.KEYCODE_VOLUME_UP:
　case KeyEvent.KEYCODE_VOLUME_DOWN:
　Log.v(TAG,"KEYCODE_VOLUME_UP/DOWN long pressed");
　lockLongPressKey = true;
　onShutterButtonLongPressed();
　return true;
　default:
　break;
　}
　return super.onKeyLongPress(keyCode, event);
　}

　public boolean onKeyUp(int keyCode, KeyEvent event) {
　switch (keyCode) {
　case KeyEvent.KEYCODE_VOLUME_UP:
　case KeyEvent.KEYCODE_VOLUME_DOWN:
　Log.v(TAG, "onKeyUp event.getRepeatCount() "+event.getRepeatCount());
　if(lockLongPressKey){
　lockLongPressKey = false;
　return true;
　}
　if (event.getRepeatCount() == 0) {
　Log.v(TAG, "prepare for onShutterButtonClick..");
　if (mEnableRecordBtn && mReviewImage.getVisibility() != View.VISIBLE
　&& mBgLearningMessageFrame.getVisibility() == View.GONE) {
　if (mShutterButton != null && mShutterButton.isEnabled()) {
　onShutterButtonFocus(false);
　collapseCameraControls();//fulin@20121101@fix PD1218 B121027-224
　onShutterButtonClick();
　}
　}
　}
　if (mCameraAppView.getVisibility() != View.VISIBLE) {
　return false;
　}
　return true;
　}
　return super.onKeyUp(keyCode, event);
　}

import android.app.Activity;
　　import android.os.Bundle;
　　import android.view.View;
　　import android.view.View.OnLongClickListener;
　　import android.widget.Button;
　　import android.widget.Toast;
　　public class MyActivity extends Activity implements OnLongClickListener{
　　Button button;//声明按钮的引用
　　public void onCreate(Bundle savedInstanceState) {//重写的onCreate方法
　　super.onCreate(savedInstanceState);
　　setContentView(R.layout.main);
　　button = (Button) this.findViewById(R.id.button);//得到按钮的引用
　　button.setTextSize(20);
　　button.setOnLongClickListener(this);//注册监听
　　}
　　public boolean onLongClick(View v) {//实现接口中的方法
　　if(v == button){//当按下的是按钮时
　　Toast.makeText(
　　this,
　　"长时间按下了按钮",
　　Toast.LENGTH_SHORT
　　).show();//显示提示
　　}
　　return false;
　　}
　　}