滚动到滚动视图中的特定视图 [英] Scroll to a specific view in scroll view

问题描述

我在滚动视图中添加了一个滚动视图和子对象.在某些时候，我需要滚动到一个特定的视图.

I have added a scrollview and the subchilds inside the scrollview. At some point i need to scroll to a specific view.

<scrollview>

1. <linearlayout>

    <textview></textview>
    <textview></textview>

   </linearlayout>

2. <linearlayout>

    <textview></textview>
    <textview></textview>

   </linearlayout>

3. <linearlayout>

    <textview></textview>
    <textview></textview>

   </linearlayout>

4. <linearlayout>

    <textview></textview>
    <textview></textview>

   </linearlayout>

5. <linearlayout>

    <textview></textview>
    <textview></textview>

   </linearlayout>

6. <linearlayout>

    <textview></textview>
    <textview></textview>

   </linearlayout>

7. <linearlayout>

    <textview></textview>
    <textview></textview>

   </linearlayout>

   <button>
   </button>

 </scrollview>

以上布局是动态创建的.所以我不能在这里发布xml文件.布局创建是完全动态的.甚至线性布局内的子视图数量也可能会发生变化.

The above layout was created dynamically. so i can't have the xml file posted here. Layout creation is completely dynamic. Even the number of child view inside the linearlayout may also vary.

因此，当我单击按钮时，我需要滚动到特定视图，在这里单击按钮时，我需要滚动到线性布局4. 我尝试了scrollTo方法，但它滚动到了scrollview的顶部.

So when i click on the button i need to get scrolled to a particular view say here when i click on button i need to scroll to the linear layout 4. I tried with the scrollTo method but it scrolls to the top of the scrollview.

请提供一些建议.

推荐答案

如果我们需要滚动到的孩子不是直接孩子，则上述解决方案将不起作用

If child that we need to scroll to is not a direct child then above solutions don't work

我在项目中使用了以下解决方案，与他人共享可能会有所帮助

I have used below solution in my project, sharing it may be helpful to others

/**
 * Used to scroll to the given view.
 *
 * @param scrollViewParent Parent ScrollView
 * @param view View to which we need to scroll.
 */
private void scrollToView(final ScrollView scrollViewParent, final View view) {
    // Get deepChild Offset
    Point childOffset = new Point();
    getDeepChildOffset(scrollViewParent, view.getParent(), view, childOffset);
    // Scroll to child.
    scrollViewParent.smoothScrollTo(0, childOffset.y);
}

/**
 * Used to get deep child offset.
 * <p/>
 * 1. We need to scroll to child in scrollview, but the child may not the direct child to scrollview.
 * 2. So to get correct child position to scroll, we need to iterate through all of its parent views till the main parent.
 *
 * @param mainParent        Main Top parent.
 * @param parent            Parent.
 * @param child             Child.
 * @param accumulatedOffset Accumulated Offset.
 */
private void getDeepChildOffset(final ViewGroup mainParent, final ViewParent parent, final View child, final Point accumulatedOffset) {
    ViewGroup parentGroup = (ViewGroup) parent;
    accumulatedOffset.x += child.getLeft();
    accumulatedOffset.y += child.getTop();
    if (parentGroup.equals(mainParent)) {
        return;
    }
    getDeepChildOffset(mainParent, parentGroup.getParent(), parentGroup, accumulatedOffset);
}

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