public class MyView extends View{
private int textX = 20,textY = 20;
public MyView(Context context) {
super(context);
setFocusable(true);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_DPAD_UP) {
textY-= 2;
}else if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN) {
textY+= 2;
}else if (keyCode == KeyEvent.KEYCODE_DPAD_LEFT) {
textX-= 2;
}else if (keyCode == KeyEvent.KEYCODE_DPAD_RIGHT) {
textX+= 2;
}
return super.onKeyDown(keyCode, event);
}
@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
//invalidate();不能在当前子线程中循环调用执行
//postInvalidate(); 可以在子线程中循环调用执行
invalidate();
return super.onKeyUp(keyCode, event);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
int x = (int) event.getX();
int y = (int) event.getY();
textX =x;
textY = y;
invalidate();
return true;
}
@Override
protected void onDraw(Canvas canvas) {
Paint paint = new Paint();
paint.setColor(Color.BLUE);
paint.setTextSize(18);
canvas.drawText("我厉害不", textX, textY, paint);
super.onDraw(canvas);
}
}
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new MyView(this));
}
}
