listview直到我触摸它才向上滚动

i have a listView and a button ... when i scroll down on the list .. the button which i named 'scroll_up' appears, so when i click it the list should scroll to the top.. but it didn't until i touch it.. i mean after clicking the button nothing happens ..but if i touch the list it scoll to the top ..

我有一个listView和一个按钮...当我向下滚动列表..我名为'scroll_up'的按钮出现,所以当我点击它时,列表应滚动到顶部..但它没有直到我触摸它...我的意思是在点击按钮后没有任何反应..但如果我触摸列表它scoll到顶部..

here is my button onClick

这是我的按钮onClick

public void scrollup(View v){
   lv.smoothScrollToPosition(0);
}

there is no error in the logcat... Note:I use a header in the list .. maybe this what cause the problem .. so is there a way to refresh the layout or somthing similar ?

在logcat中没有错误...注意:我在列表中使用了一个标题..也许这是导致问题的原因..那么有没有办法刷新布局或类似的东西?

2 个解决方案

#1

If you want to move to first index of the list view, use below code:

如果要移动到列表视图的第一个索引,请使用以下代码:

listView.setSelection();

#2

If you want to smooth scroll you may add line in listview in xml

如果要平滑滚动,可以在xml中的listview中添加行

android:smoothScrollbar="true"

or in code:

或在代码中:

lv.setSmoothScrollbarEnabled(true);

And after your code

并在您的代码之后

lv.smoothScrollToPosition(0);