Question

我正在尝试创建一个在Blackberry中具有主屏幕（下面为MyScreen）动画的应用程序，它使图像从屏幕的底部浮动到屏幕的中间。然后，我想推送另一个带有登录屏幕的屏幕（下面是NewScreen）。

动画后我得到一个空白屏幕。按返回一次，我将从动画屏幕中按下屏幕。请指导我：我应该在哪里推动以获得完美的结果？

import net.rim.device.api.animation.AnimatedScalar;
import net.rim.device.api.animation.Animation;
import net.rim.device.api.animation.Animator;
import net.rim.device.api.animation.AnimatorListener;
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.Display;
import net.rim.device.api.system.EncodedImage;
import net.rim.device.api.ui.Color;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.Screen;
import net.rim.device.api.ui.TransitionContext;
import net.rim.device.api.ui.Ui;
import net.rim.device.api.ui.UiApplication;
import net.rim.device.api.ui.UiEngineInstance;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.container.PopupScreen;

/**
 * A class extending the MainScreen class, which provides default standard
 * behavior for BlackBerry GUI applications.
 */

public final class MyScreen extends MainScreen implements AnimatorListener {
    private RectangleToMove _rect;
    private Animator _animator;
    private Animation _xanimation;
    private Animation _yanimation;
    private boolean _bAnimating;
    public static final int BALL_WIDTH = 50;
    public Bitmap splashimg;

    static TransitionContext transitionContextIn;
    static TransitionContext transitionContextOut;
    static UiEngineInstance engine = Ui.getUiEngineInstance();

    /**
     * Creates a new MyScreen object
     */

    public MyScreen() {
        EncodedImage img = EncodedImage.getEncodedImageResource("logo.png");
        splashimg = img.getBitmap();
        _bAnimating = false;
        int midScreen = (Display.getWidth() / 2) - img.getWidth()/2;
        int endScreen = Display.getHeight();
        _rect = new RectangleToMove(midScreen, BALL_WIDTH);
        _animator = new Animator(30);
        _animator.setAnimatorListener(this);
        _yanimation = _animator.addAnimationFromTo(_rect.getY(),
                AnimatedScalar.ANIMATION_PROPERTY_SCALAR, endScreen
                        - BALL_WIDTH, Display.getHeight() / 2-30,
                Animation.EASINGCURVE_LINEAR, 3000L);
        _yanimation.setRepeatCount(1f);
        _yanimation.begin(0);


        UiApplication.getUiApplication().pushScreen(new NewScreen());

    }

    protected void paint(Graphics g) {
        if (_bAnimating) {
            _rect.draw(g, splashimg);
        }       
    }

    public void animatorUpdate() {
        invalidate();
        doPaint();      
    }

    public void animatorProcessing(boolean processing) {
        _bAnimating = processing;
    }


}

class RectangleToMove {
    private int xPos;
    private AnimatedScalar yPos;

    public void draw(Graphics g, Bitmap splashimg) {
        g.setBackgroundColor(Color.BLACK);
        g.clear();
        g.setColor(Color.SLATEGRAY);
        g.drawBitmap(xPos, yPos.getInt(), splashimg.getWidth(),
                splashimg.getHeight(), splashimg, 0, 0);
        /*
         * g.fillEllipse(xPos,yPos.getInt(),
         * xPos+MyScreen.BALL_WIDTH,yPos.getInt(),xPos,
         * yPos.getInt()+MyScreen.BALL_WIDTH,0,360);
         */
    }

    public int getX() {
        return xPos;
    }

    public AnimatedScalar getY() {
        return yPos;
    }

    RectangleToMove(int x, int y) {

        xPos = x;
        yPos = new AnimatedScalar(y);
    }    
}

Answer 1

我并非100％确定我理解您的问题，但我编辑了您的问题以描述我认为的问题。

当动画结束时，您会看到一个您不想要的空白屏幕。您必须按Back / ESC才能使白屏消失，以便您可以返回登录屏幕（NewScreen）。我假设您不希望在第一次显示之后看到初始动画屏幕（可能是因为它是加载或 splash 屏幕）。

要执行此操作，您需要等到动画完成，然后再按第二个屏幕。因此，删除此次调用pushScreen：

    UiApplication.getUiApplication().pushScreen(new NewScreen());

你在MyScreen构造函数中有。此时，动画尚未完成，因此推送NewScreen。

为时尚早

然后，在AnimatorListener被告知动画停止时按下屏幕。如果您不希望动画屏幕可见，则在通过屏幕进行备份时，请在按下第二个屏幕后弹出：

   public void animatorProcessing(boolean processing) {
      _bAnimating = processing;
      if (!processing) {
         // the animation is complete
         UiApplication.getUiApplication().pushScreen(new NewScreen());
         // use this line if the instance of `MyScreen` should not be
         //  visible after the user presses Back/ESC:
         UiApplication.getUiApplication().popScreen(this);
      }
   }

应用程序主屏幕上的黑莓动画问题

1 个答案: