Android (界面编程#6-键盘操作响应)

      在Android中是通过触屏及键盘来操作程序的，我们如何响应一般的键盘及触笔动作呢？通过对Android一些基本界面元素的操作的了解，如果你再熟悉MVC你可以猜到Android将会如何处理键盘事件，恭喜你，猜对了，仍在Activity中改事件响应函数来做到。一般是如下三个函数：
onKeyDown, onKeyUp, on, onKeyMultiple
参看如下代码：

import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;

public class TestProgress extends Activity {
   
 private ProgressDialog progress = null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  super.onCreateOptionsMenu(menu);
  menu.add(0, Menu.FIRST+1, 1, "Open  Progress");
  menu.add(0, Menu.FIRST+2, 2, "Exit");
  return true;
 }

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
  super.onOptionsItemSelected(item);
  switch (item.getItemId())
  {
  case Menu.FIRST +1:
  {
   progress  = new ProgressDialog(this);
   progress.setTitle("Progress!!");
   progress.setMessage("Please wait for the operation...");
   progress.setCancelable(true);  
   progress.show();
   //progress = ProgressDialog.show(this, "Progress!", "Please wait for operation...");
   break;
  }
  case Menu.FIRST +2:
  { 
   finish();
   break;
  }
  }
  return true;
 }

 @Override
 public boolean onKeyDown(int keyCode, KeyEvent event) {
  // TODO Auto-generated method stub
  super.onKeyDown(keyCode, event);
  setTitle("you pressed key:" + String.valueOf(keyCode));
  return true;
 }

 @Override
 public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) {
  // TODO Auto-generated method stub
  super.onKeyMultiple(keyCode, repeatCount, event);
  TextView tv = (TextView)this.findViewById(R.id.mainview);
  tv.setText("you have press key:[" + String.valueOf(keyCode) + "] for:" + String.valueOf(repeatCount) + "Times!");
  return true;
 }

 @Override
 public boolean onKeyUp(int keyCode, KeyEvent event) {
  // TODO Auto-generated method stub
  super.onKeyUp(keyCode, event);
  setTitle("you release key:" + String.valueOf(keyCode));
  return true;
 }
}