是否有一种方法以编程方式滚动滚动视图到特定的编辑文本?

小开

最佳答案

private final void focusOnView(){
yourScrollView.post(new Runnable() {
@Override
public void run() {
yourScrollView.scrollTo(0, yourEditText.getBottom());
}
});
}

小开

你应该让你的TextView请求聚焦:

    mTextView.requestFocus();

小开

Sherif elKhatib的答案可以大大提高，如果你想将视图滚动到滚动视图的中心。这个可重用的方法平滑地将视图滚动到HorizontalScrollView的可见中心。

private final void focusOnView(final HorizontalScrollView scroll, final View view) {
new Handler().post(new Runnable() {
@Override
public void run() {
int vLeft = view.getLeft();
int vRight = view.getRight();
int sWidth = scroll.getWidth();
scroll.smoothScrollTo(((vLeft + vRight - sWidth) / 2), 0);
}
});
}

用于垂直ScrollView的使用

...
int vTop = view.getTop();
int vBottom = view.getBottom();
int sHeight = scroll.getBottom();
scroll.smoothScrollTo(0, ((vTop + vBottom - sHeight) / 2));
...

小开

另一种说法是:

scrollView.postDelayed(new Runnable()
{
@Override
public void run()
{
scrollView.smoothScrollTo(0, img_transparent.getTop());
}
}, 200);

或者你可以使用post()方法。

小开

我基于WarrenFaith的答案做了一个小工具方法，这段代码也考虑了视图是否已经在滚动视图中可见，不需要滚动。

public static void scrollToView(final ScrollView scrollView, final View view) {


// View needs a focus
view.requestFocus();


// Determine if scroll needs to happen
final Rect scrollBounds = new Rect();
scrollView.getHitRect(scrollBounds);
if (!view.getLocalVisibleRect(scrollBounds)) {
new Handler().post(new Runnable() {
@Override
public void run() {
scrollView.smoothScrollTo(0, view.getBottom());
}
});
}
}

小开

我的EditText在ScrollView中嵌套了几个层，而ScrollView本身并不是布局的根视图。因为getTop()和getBottom()似乎在报告它所包含的视图中的坐标，所以我让它通过迭代EditText的父节点来计算从ScrollView顶部到EditText顶部的距离。

// Scroll the view so that the touched editText is near the top of the scroll view
new Thread(new Runnable()
{
@Override
public
void run ()
{
// Make it feel like a two step process
Utils.sleep(333);


// Determine where to set the scroll-to to by measuring the distance from the top of the scroll view
// to the control to focus on by summing the "top" position of each view in the hierarchy.
int yDistanceToControlsView = 0;
View parentView = (View) m_editTextControl.getParent();
while (true)
{
if (parentView.equals(scrollView))
{
break;
}
yDistanceToControlsView += parentView.getTop();
parentView = (View) parentView.getParent();
}


// Compute the final position value for the top and bottom of the control in the scroll view.
final int topInScrollView = yDistanceToControlsView + m_editTextControl.getTop();
final int bottomInScrollView = yDistanceToControlsView + m_editTextControl.getBottom();


// Post the scroll action to happen on the scrollView with the UI thread.
scrollView.post(new Runnable()
{
@Override
public void run()
{
int height =m_editTextControl.getHeight();
scrollView.smoothScrollTo(0, ((topInScrollView + bottomInScrollView) / 2) - height);
m_editTextControl.requestFocus();
}
});
}
}).start();

小开

参考:https://stackoverflow.com/a/6438240/2624806

接下来的工作要好得多。

mObservableScrollView.post(new Runnable() {
public void run() {
mObservableScrollView.fullScroll([View_FOCUS][1]);
}
});

小开

这对我来说很管用:

  targetView.getParent().requestChildFocus(targetView,targetView);

RequestChildFocus(查看子视图，查看焦点)

孩子 -这个ViewParent的子对象。该视图将包含聚焦视图。它并不一定是真正有焦点的观点。

集中 -实际上有焦点的child的后代视图

小开

检查Android源代码，你会发现已经有一个成员函数ScrollView - scrollToChild(View) -，它做的正是所请求的。不幸的是，这个函数由于某种模糊的原因被标记为private。基于该函数，我写了以下函数，它找到作为参数指定的View之上的第一个ScrollView，并滚动它，使它在ScrollView中可见:

 private void make_visible(View view)
{
int vt = view.getTop();
int vb = view.getBottom();


View v = view;


for(;;)
{
ViewParent vp = v.getParent();


if(vp == null || !(vp instanceof ViewGroup))
break;


ViewGroup parent = (ViewGroup)vp;


if(parent instanceof ScrollView)
{
ScrollView sv = (ScrollView)parent;


// Code based on ScrollView.computeScrollDeltaToGetChildRectOnScreen(Rect rect) (Android v5.1.1):


int height = sv.getHeight();
int screenTop = sv.getScrollY();
int screenBottom = screenTop + height;


int fadingEdge = sv.getVerticalFadingEdgeLength();


// leave room for top fading edge as long as rect isn't at very top
if(vt > 0)
screenTop += fadingEdge;


// leave room for bottom fading edge as long as rect isn't at very bottom
if(vb < sv.getChildAt(0).getHeight())
screenBottom -= fadingEdge;


int scrollYDelta = 0;


if(vb > screenBottom && vt > screenTop)
{
// need to move down to get it in view: move down just enough so
// that the entire rectangle is in view (or at least the first
// screen size chunk).


if(vb-vt > height) // just enough to get screen size chunk on
scrollYDelta += (vt - screenTop);
else              // get entire rect at bottom of screen
scrollYDelta += (vb - screenBottom);


// make sure we aren't scrolling beyond the end of our content
int bottom = sv.getChildAt(0).getBottom();
int distanceToBottom = bottom - screenBottom;
scrollYDelta = Math.min(scrollYDelta, distanceToBottom);
}
else if(vt < screenTop && vb < screenBottom)
{
// need to move up to get it in view: move up just enough so that
// entire rectangle is in view (or at least the first screen
// size chunk of it).


if(vb-vt > height)    // screen size chunk
scrollYDelta -= (screenBottom - vb);
else                  // entire rect at top
scrollYDelta -= (screenTop - vt);


// make sure we aren't scrolling any further than the top our content
scrollYDelta = Math.max(scrollYDelta, -sv.getScrollY());
}


sv.smoothScrollBy(0, scrollYDelta);
break;
}


// Transform coordinates to parent:
int dy = parent.getTop()-parent.getScrollY();
vt += dy;
vb += dy;


v = parent;
}
}

小开

在我的例子中，这不是EditText，而是googleMap。

    private final void focusCenterOnView(final ScrollView scroll, final View view) {
new Handler().post(new Runnable() {
@Override
public void run() {
int centreX=(int) (view.getX() + view.getWidth()  / 2);
int centreY= (int) (view.getY() + view.getHeight() / 2);
scrollView.smoothScrollBy(centreX, centreY);
}
});
}

小开

在我看来，滚动到给定矩形的最好方法是通过View.requestRectangleOnScreen(Rect, Boolean)。你应该在你想要滚动到的View上调用它，并传递一个你想要在屏幕上可见的局部矩形。第二个参数应该是false用于平滑滚动，true用于立即滚动。

final Rect rect = new Rect(0, 0, view.getWidth(), view.getHeight());
view.requestRectangleOnScreen(rect, false);