为什么在 Android 中应用 ScaleAnimation 时,drawable 的位置也会发生变化?
我正在尝试使用代码而不是 xml 将缩放动画应用于矩形。我想让矩形长高,很简单。
RectDrawableView - 创建一个 RectShape ShapeDrawable
public class RectDrawableView extends View {
Paint paint;
public RectDrawableView(Context context) {
super(context);
paint = new Paint();
paint.setColor(Color.parseColor("#aacfcce4"));
paint.setStyle(Paint.Style.FILL);
}
protected void onDraw(Canvas canvas) {
int x = 35;
int y = 250;
int width = 50;
int height = 300;
ShapeDrawable shapeDrawable = new ShapeDrawable(new RectShape());
Rect rect = new Rect(x, y, x+width, y+height);
shapeDrawable.setBounds(rect);
shapeDrawable.getPaint().set(paint);
shapeDrawable.draw(canvas);
}
}
活动: - 创建一个新的 RectDrawableView 并添加到布局中。 OnResume 会触发动画,这将使矩形变高。
public class RectActivity extends Activity {
final String TAG = "RectActivity";
TextView rect1;
RectDrawableView rectView;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.basic);
LinearLayout linear = (LinearLayout) findViewById(R.id.basicLayout);
rectView = new RectDrawableView(this);
linear.addView(rectView);
}
@Override
public void onResume() {
super.onResume();
RunAnimations();
}
private void RunAnimations() {
Animation rectAnim1 = new ScaleAnimation(1, 1, 1, 1.3f, ScaleAnimation.RELATIVE_TO_SELF, 0,
ScaleAnimation.RELATIVE_TO_SELF, 1);
rectAnim1.setFillBefore(false);
rectAnim1.setFillAfter(true);
rectAnim1.setStartOffset(500);
rectAnim1.setDuration(500);
rectView.startAnimation(rectAnim1);
}
}
basic.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/basicLayout"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
</LinearLayout>
结果:矩形越来越高,很好,但是矩形的位置也在变化,很糟糕。整个矩形位于屏幕上方。
当我使用完全相同的动画代码,但将其应用于 TextView 而不是 ShapeDrawable 时,一切都很好。
我已经浏览了所有关于 SO 的相关文章,但我仍在为这篇文章而苦苦挣扎。任何帮助将不胜感激,谢谢。
I am trying to apply a scale animation to a rectangle, using code not xml. I want to make the rectangle grow taller, pretty simple.
RectDrawableView - creates a RectShape ShapeDrawable
public class RectDrawableView extends View {
Paint paint;
public RectDrawableView(Context context) {
super(context);
paint = new Paint();
paint.setColor(Color.parseColor("#aacfcce4"));
paint.setStyle(Paint.Style.FILL);
}
protected void onDraw(Canvas canvas) {
int x = 35;
int y = 250;
int width = 50;
int height = 300;
ShapeDrawable shapeDrawable = new ShapeDrawable(new RectShape());
Rect rect = new Rect(x, y, x+width, y+height);
shapeDrawable.setBounds(rect);
shapeDrawable.getPaint().set(paint);
shapeDrawable.draw(canvas);
}
}
Activity: - Creates a new RectDrawableView and adds to layout. OnResume an animation is triggered, which should make the rectangle grow taller.
public class RectActivity extends Activity {
final String TAG = "RectActivity";
TextView rect1;
RectDrawableView rectView;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.basic);
LinearLayout linear = (LinearLayout) findViewById(R.id.basicLayout);
rectView = new RectDrawableView(this);
linear.addView(rectView);
}
@Override
public void onResume() {
super.onResume();
RunAnimations();
}
private void RunAnimations() {
Animation rectAnim1 = new ScaleAnimation(1, 1, 1, 1.3f, ScaleAnimation.RELATIVE_TO_SELF, 0,
ScaleAnimation.RELATIVE_TO_SELF, 1);
rectAnim1.setFillBefore(false);
rectAnim1.setFillAfter(true);
rectAnim1.setStartOffset(500);
rectAnim1.setDuration(500);
rectView.startAnimation(rectAnim1);
}
}
basic.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/basicLayout"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
</LinearLayout>
Result: The rect is growing taller, good, but the location of the rect is also changing, bad. The whole rectangle is being positioned higher up the screen.
When I use this exact same animation code, but apply it to a TextView instead of a ShapeDrawable, all is good.
I've trawled through all the related articles on SO, but I'm still struggling with this one. Any help would be appreciated, thanks.
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完整的代码,我改变了矩形的高度。
Complete code, i had changed the height of the rectangle.
试试这个代码。将
pivotYType
保持为 ABSOLUTE,值为550 ( y + height )
Try this code. Keep the
pivotYType
as ABSOLUTE with value550 ( y + height )