/*
* DPAD按键处理
* 当程序onCreate()时就调用RestoreButton(),这是一个自定义
* 的方法,目的是判断手机的屏幕分辨率,并将按钮居中存放。
* Activity重写了onKeyDown()方法,其传入的参数是keyCode和
* keyEvent,前者为按键代码,后者为KeyEvent对象,其常见的构建
* 方法是KeyEvent(int action,int code)。
* keyCode是与KeyEvent.KEYCODE_*进行比较来做判断的。
*/
import 略;
public class Ex05_20Activity extends Activity {
private Button bt;
private int intWidth, intHeight, intButtonX, intButtonY;
// 保存屏幕的分辨率
private int intScreenX, intScreenY;
// 按钮位移的平移量
private int intShift = 2;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// 获取屏幕的分辨率
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
intScreenX = dm.widthPixels;
intScreenY = dm.heightPixels;
// 定义按钮的宽高
intWidth = 80;
intHeight = 60;
bt = (Button) findViewById(R.id.myButton1);
// 初始化按钮的位置
RestoreButton();
// 当按下按钮,还原初始化位置
bt.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
RestoreButton();
}
});
}
public boolean onKeyDown(int keyCode, KeyEvent event) {
switch (keyCode) {
case KeyEvent.KEYCODE_DPAD_CENTER:
RestoreButton();
break;
case KeyEvent.KEYCODE_DPAD_UP:
MoveButtonUp();
break;
case KeyEvent.KEYCODE_DPAD_DOWN:
MoveButtonDown();
break;
case KeyEvent.KEYCODE_DPAD_LEFT:
MoveButtonLeft();
case KeyEvent.KEYCODE_DPAD_RIGHT:
MoveButtonRight();
break;
default:
break;
}
return super.onKeyDown(keyCode, event);
}
@SuppressWarnings("deprecation")
private void MoveButtonRight() {
// TODO Auto-generated method stub
intButtonX = intButtonY - intShift;
if (intButtonX > (intScreenX - intHeight)) {
intButtonX = intScreenX - intHeight;
bt.setLayoutParams(new AbsoluteLayout.LayoutParams(intWidth,
intHeight, intButtonX, intButtonY));
}
}
@SuppressWarnings("deprecation")
private void MoveButtonLeft() {
// TODO Auto-generated method stub
intButtonX = intButtonX- intShift;
if (intButtonY < 0) {
intButtonY = 0;
bt.setLayoutParams(new AbsoluteLayout.LayoutParams(intWidth,
intHeight, intButtonX, intButtonY));
}
}
@SuppressWarnings("deprecation")
private void MoveButtonDown() {
// TODO Auto-generated method stub
intButtonY = intButtonY + intShift;
if (intButtonY > (intScreenY - intHeight)) {
intButtonY = intScreenY - intHeight;
bt.setLayoutParams(new AbsoluteLayout.LayoutParams(intWidth,
intHeight, intButtonX, intButtonY));
}
}
@SuppressWarnings("deprecation")
private void MoveButtonUp() {
// TODO Auto-generated method stub
intButtonY = intButtonY - intShift;
if (intButtonY < 0) {
intButtonY = 0;
bt.setLayoutParams(new AbsoluteLayout.LayoutParams(intWidth,
intHeight, intButtonX, intButtonY));
}
}
@SuppressWarnings("deprecation")
private void RestoreButton() {
// TODO Auto-generated method stub
intButtonX = (intScreenX - intWidth) / 2;
intButtonY = (intScreenY - intHeight) / 2;
Toast.makeText(Ex05_20Activity.this, "(" + Integer.toString(intButtonX)
+ "," + Integer.toString(intButtonY), Toast.LENGTH_SHORT);
bt.setLayoutParams(new AbsoluteLayout.LayoutParams(intWidth, intHeight,
intButtonX, intButtonY));
}
}
main.xml文件代码:
<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/white"
android:orientation="vertical" >
<Button
android:id="@+id/myButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_x="20px"
android:layout_y="40px"
android:text="@string/str_button1" />
</AbsoluteLayout>