我试图取得与这个问题同样的效果。 我努力争取它, 然后我读了@wnafee 回答(我无法用它来做) 。
But then I struggle to implement what was sound pretty simple from the answer.
I had so much trouble with implementing it, that I might didn t understand the answer correctly, but there were too many issues of inaccessible APIs since I wasn t working in the same package of the Compatibility library.
在我尝试了一些方法(其中没有一个成功,而且相当复杂)之后,我走到了一个略微不同的方向,现在它像一个符咒一样运作。 我用了一些反思,对于从未使用过它的人来说,不要担心它确实是反省的基础。
我不确定这是不是最好的解决方案,但它对我有效,所以如果你愿意使用它,欢迎你。请阅读Wnafee的例子,因为它解释了我所做的一些事情。
为了完成这项任务,你应该遵循我的三部分解决方案。 (3至10分钟之间)
<强 > 第一部分:
正如Wnafee所说,我刚刚通过拷贝将的源代码贴上,
(just make sure to copy the overscroll_edge and overscroll_glow
drawables in the AOSP /res/drawable directories to your own project
since they are internal to android)
我只做了两个很小的改变:
- I declare that the class extends EdgeEffectCompat (I called my class
EdgeEffectForEarlyVersions). public class EdgeEffectForEarlyVersions extends EdgeEffectCompat. The reason for doing this change is that the mLeftEdge and mRightEdge are of the type EdgeEffectCompat.
- At the first line of the constructor of "my" new class I added a call to the parent constructor
super(context);. Since there is no default constructor to EdgeEffectCompat you have to Explicitly call the constructor.
<强 > 第二部分
此外,我还写了另一个函数。该函数的目的是,如果有一个早期版本(在ICS之前),我们希望使用我们刚刚复制的 < code> EdgeEffectForEarlyVersions 。为了达到这个目的,我使用了反省。
这就是这个函数:
private static void changeEdgeEffectCompactOnEarlyVersions(ViewPager viewPager, Context context)
{
/* In case that the version is earlier than 14 there is only empty implementation for the edge effect, therefore we change it.
* for more information look on the following links:
* 1. http://stackoverflow.com/questions/10773565/visual-indication-of-over-scroll-in-android
* 2. http://grepcode.com/file/repo1.maven.org/maven2/com.google.android/support-v4/r7/android/support/v4/view/ViewPager.java#ViewPager.0mLeftEdge
* 3. http://grepcode.com/file/repo1.maven.org/maven2/com.google.android/support-v4/r7/android/support/v4/widget/EdgeEffectCompat.java#EdgeEffectCompat
*/
if (Build.VERSION.SDK_INT < 14)
{
try
{
Class<ViewPager> viewPagerClass = ViewPager.class;
//Get the left edge field, since it is private we used getDeclaredField and not getDeclared
Field leftEdge = viewPagerClass.getDeclaredField("mLeftEdge");
leftEdge.setAccessible(true);
//Get the right edge field, since it is private we used getDeclaredField and not getDeclared
Field rightEdge = viewPagerClass.getDeclaredField("mRightEdge");
rightEdge.setAccessible(true);
EdgeEffectForEarlyVersions leftEdgeEffect = new EdgeEffectForEarlyVersions(context);
EdgeEffectForEarlyVersions rightEdgeEffect = new EdgeEffectForEarlyVersions(context);
//Set the mLeftEdge memeber of viewPager not to be the default one, but to be "our" edgeEffect
leftEdge.set(viewPager, leftEdgeEffect);
//Set the mRightEdge memeber of viewPager not to be the default one, but to be "our" edgeEffect
rightEdge.set(viewPager, rightEdgeEffect);
}
catch (Exception ex)
{
Log.e("refelection", ex.getMessage());
}
}
}
<强 > 第三部分
现在只有剩下的事可做, 就是在您有了 ViewPager Incent( ViewPager Incentral) 之后调用该函数, 仅此而已 。
我希望它能帮助别人
