我正在尝试为自定义菜单创建切换动画。有多个菜单可以通过不同的按钮选择。没有菜单打开时，点击按钮应打开该菜单。如果打开另一个菜单，则打开一个菜单，在该动画之后，应打开所选菜单。每个结束/打开操作都与ConstraintLayout转换相结合。
由于它无法正常工作，我创建了以下测试程序：
@Override
protected void onCreate(Bundle savedInstanceState) {
...
ConstraintLayout layout_main;
ConstraintSet l_mh0c = new ConstraintSet();
ConstraintSet l_mh1o = new ConstraintSet();
ConstraintSet l_mh1c = new ConstraintSet();
Button btn;
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
toggleOne();
}
});
layout_main = (ConstraintLayout) findViewById(R.id.constraintMain);
l_mh1o.clone(this, R.layout.main_menue_header1_open);
l_mh1c.clone(this, R.layout.main_menue_header1_closed);
l_mh0c.clone(this, R.layout.activity_main);
...
}
int openedMenue = -1;
long animationTime = 1000;
private void toggleOne() {
TransitionManager.endTransitions(layout_main); //<- makes no difference when commented
if(openedMenue==1) {
System.out.println("sync closing");
Runnable r = () -> toggleOne();
closeMenue(1, animationTime, r);
} else {
System.out.println("sync opening");
startMenue(1, animationTime);
}
}
public void startMenue(Integer index, final Long maxtime) {
Transition t;
switch (index) {
case 1:
t = new ChangeBounds();
t.setDuration(0).addListener(new TransitionEndListener() {
@Override
public void onTransitionEnd(Transition transition) {
Transition t = new ChangeBounds();
t.setDuration(maxtime / 2).addListener(new TransitionEndListener() {
@Override
public void onTransitionEnd(Transition transition) {
Transition t = new ChangeBounds();
t.setDuration(maxtime / 2);
TransitionManager.beginDelayedTransition(layout_main, t);
l_mh0o.applyTo(layout_main);
openedMenue = 1;
System.out.println("sync start finished");
}
});
TransitionManager.beginDelayedTransition(layout_main, t);
l_mh1o.applyTo(layout_main);
}
});
TransitionManager.beginDelayedTransition(layout_main, t);
l_mh1c.applyTo(layout_main);
// the following does not provoke any changes
Scene s = new Scene(layout_main);
TransitionManager.go(s);
break;
}
}
private void closeMenue(int index, final long maxtime, Runnable callback) {
System.out.println("sync closing menue " + openedMenue);
Transition t;
switch (index) {
case 1:
t = new ChangeBounds();
t.setDuration(maxtime/2).addListener(new TransitionEndListener() {
@Override
public void onTransitionEnd(Transition transition) {
Transition t = new ChangeBounds();
t.setDuration(maxtime/2).addListener(new TransitionEndListener() {
@Override
public void onTransitionEnd(Transition transition) {
Transition t = new ChangeBounds();
t.setDuration(0);
TransitionManager.beginDelayedTransition(layout_main, t);
l_mh0c.applyTo(layout_main);
openedMenue = -1;
try {
callback.run();
} catch (Exception e) { e.printStackTrace(); }
}
});
TransitionManager.beginDelayedTransition(layout_main, t);
l_mh1c.applyTo(layout_main);
openedMenue = 1;
}
});
TransitionManager.beginDelayedTransition(layout_main, t);
l_mh1o.applyTo(layout_main);
break;
}
}
当我运行它时，我得到以下输出：
[Button Click]
sync opening
sync start finished
[Button Click]
sync closing
sync closing menue 1
sync opening
sync start finished // problem
但是，最后一行从未打印过;似乎（在关闭操作再次开始打开操作之后）startMenue（）中的第一个转换从不对onTransitionEnd（）进行回调。
这是TransitionEndListener（只是一个简单的接口包装器）
public abstract class TransitionEndListener implements Transition.TransitionListener {
@Override
public final void onTransitionStart(Transition transition) {}
@Override
public final void onTransitionCancel(Transition transition) {}
@Override
public final void onTransitionPause(Transition transition) {}
@Override
public final void onTransitionResume(Transition transition) {}
}
我已经检查了是否通过在onTransitionCancel（）中放置一个print语句来取消第二个启动Transition，这似乎不是这种情况。
你能解释一下为什么会这样吗？
UPDATE
我找到了this post on TransitionManager callbacks;
从mh0c t0 mh1c的转换是ConstraintLayout转换，因为约束实际上发生了变化;但是，转换在UI上不可见，因为转换中元素的宽度为0.（此转换是从一个菜单点跳转到另一个不应该可见的菜单点。）
这可能是Transition不进行回调的原因吗？
如果是这样;我怎么能绕过这个？
更新2我正在阅读the documentation，可能已经找到了使用TransitionManager.go(scene, transition)的解决方案。
- >不幸的是这没用;请参阅startMenue（）代码以了解更改
经过越来越多的努力和审查这些帖子：
我发现是什么造成了麻烦：
在closeMenue（）的最内部（最内部回调）
Transition t = new ChangeBounds();
t.setDuration(0);
TransitionManager.beginDelayedTransition(layout_main, t);
l_mh0c.applyTo(layout_main);
openedMenue = -1;
try {
callback.run();
} catch (Exception e) { e.printStackTrace(); }
命令序列略有错误。它应该如下所示：
Transition t = new ChangeBounds();
t.setDuration(0).addListener(new TransitionEndListener() {
@Override
public void onTransitionEnd(Transition transition) {
try {
callback.run();
} catch (Exception e) { e.prtinStackTrace(); }
}
});
TransitionManager.beginDelayedTransition(layout_main, t);
l_mh0c.applyTo(layout_main);
openedMenue = -1;
这确保首先完成关闭过渡，然后开始开始转换。