Can I scroll a ScrollView programmatically in Android?
Is there any way to scroll a ScrollView
programmatically to a 开发者_Python百科certain position?
I have created dynamic TableLayout
which is placed in a ScrollView
. So I want that on a specific action (like clicking a Button, etc.) the particular row should scroll automatically to a top position.
Is it possible?
The answer from Pragna does not work always, try this:
mScrollView.post(new Runnable() {
public void run() {
mScrollView.scrollTo(0, mScrollView.getBottom());
}
});
or
mScrollView.post(new Runnable() {
public void run() {
mScrollView.fullScroll(mScrollView.FOCUS_DOWN);
}
});
if You want to scroll to start
mScrollView.post(new Runnable() {
public void run() {
mScrollView.fullScroll(mScrollView.FOCUS_UP);
}
});
ScrollView sv = (ScrollView)findViewById(R.id.scrl);
sv.scrollTo(0, sv.getBottom());
or
sv.scrollTo(5, 10);
I wanted the scrollView to scroll directly after onCreateView() (not after e.g. a button click). To get it to work I needed to use a ViewTreeObserver:
mScrollView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
mScrollView.post(new Runnable() {
public void run() {
mScrollView.fullScroll(View.FOCUS_DOWN);
}
});
}
});
But beware that this will be called everytime something gets layouted (e.g if you set a view invisible or similar) so don't forget to remove this listener if you don't need it anymore with:
public void removeGlobalOnLayoutListener (ViewTreeObserver.OnGlobalLayoutListener victim)
on SDK Lvl < 16
or
public void removeOnGlobalLayoutListener (ViewTreeObserver.OnGlobalLayoutListener victim)
in SDK Lvl >= 16
There are a lot of good answers here, but I only want to add one thing. It sometimes happens that you want to scroll your ScrollView to a specific view of the layout, instead of a full scroll to the top or the bottom.
A simple example: in a registration form, if the user tap the "Signup" button when a edit text of the form is not filled, you want to scroll to that specific edit text to tell the user that he must fill that field.
In that case, you can do something like that:
scrollView.post(new Runnable() {
public void run() {
scrollView.scrollTo(0, editText.getBottom());
}
});
or, if you want a smooth scroll instead of an instant scroll:
scrollView.post(new Runnable() {
public void run() {
scrollView.smoothScrollTo(0, editText.getBottom());
}
});
Obviously you can use any type of view instead of Edit Text. Note that getBottom() returns the coordinates of the view based on its parent layout, so all the views used inside the ScrollView should have only a parent (for example a Linear Layout).
If you have multiple parents inside the child of the ScrollView, the only solution i've found is to call requestChildFocus on the parent view:
editText.getParent().requestChildFocus(editText, editText);
but in this case you cannot have a smooth scroll.
I hope this answer can help someone with the same problem.
Use something like this:
mScrollView.scrollBy(10, 10);
or
mScrollView.scrollTo(10, 10);
Try using scrollTo
method More Info
If you want to scroll instantly then you can use :
ScrollView scroll= (ScrollView)findViewById(R.id.scroll);
scroll.scrollTo(0, scroll.getBottom());
OR
scroll.fullScroll(View.FOCUS_DOWN);
OR
scroll.post(new Runnable() {
@Override
public void run() {
scroll.fullScroll(View.FOCUS_DOWN);
}
});
Or if you want to scroll smoothly and slowly so you can use this:
private void sendScroll(){
final Handler handler = new Handler();
new Thread(new Runnable() {
@Override
public void run() {
try {Thread.sleep(100);} catch (InterruptedException e) {}
handler.post(new Runnable() {
@Override
public void run() {
scrollView.fullScroll(View.FOCUS_DOWN);
}
});
}
}).start();
}
**to scroll up to desired height. I have come up with some good solution **
scrollView.postDelayed(new Runnable() {
@Override
public void run() {
scrollView.scrollBy(0, childView.getHeight());
}
}, 100);
Yes, you can.
Let's say you got one Layout
and inside that, you got many Views
. So if you want to scroll to any View
programmatically, you have to write the following code snippet:
For example:
content_main.xml
<ScrollView
android:id="@+id/scrollView"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<Button
android:id="@+id/btn"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/txtView"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
</ScrollView>
MainActivity.java
ScrollView scrollView = (ScrollView) findViewById(R.id.scrollView);
Button btn = (Button) findViewById(R.id.ivEventBanner);
TextView txtView = (TextView) findViewById(R.id.ivEditBannerImage);
If you want to scroll to a specific View
, let's say txtview, in this case, just write:
scrollView.smoothScrollTo(txtView.getScrollX(),txtView.getScrollY());
And you are done.
I got this to work to scroll to the bottom of a ScrollView (with a TextView inside):
(I put this on a method that updates the TextView)
final ScrollView myScrollView = (ScrollView) findViewById(R.id.myScroller);
myScrollView.post(new Runnable() {
public void run() {
myScrollView.fullScroll(View.FOCUS_DOWN);
}
});
Note: if you already in a thread, you have to make a new post thread, or it's not scroll new long height till the full end (for me). For ex:
void LogMe(final String s){
runOnUiThread(new Runnable() {
public void run() {
connectionLog.setText(connectionLog.getText() + "\n" + s);
final ScrollView sv = (ScrollView)connectLayout.findViewById(R.id.scrollView);
sv.post(new Runnable() {
public void run() {
sv.fullScroll(sv.FOCUS_DOWN);
/*
sv.scrollTo(0,sv.getBottom());
sv.scrollBy(0,sv.getHeight());*/
}
});
}
});
}
Adding another answer that does not involve coordinates.
This will bring your desired view to focus (but not to the top position) :
yourView.getParent().requestChildFocus(yourView,yourView);
public void RequestChildFocus (View child, View focused)
child - The child of this ViewParent that wants focus. This view will contain the focused view. It is not necessarily the view that actually has focus.
focused - The view that is a descendant of child that actually has focus
Everyone is posting such complicated answers.
I found an easy answer, for scrolling to the bottom, nicely:
final ScrollView myScroller = (ScrollView) findViewById(R.id.myScrollerView);
// Scroll views can only have 1 child, so get the first child's bottom,
// which should be the full size of the whole content inside the ScrollView
myScroller.smoothScrollTo( 0, myScroller.getChildAt( 0 ).getBottom() );
And, if necessary, you can put the second line of code, above, into a runnable:
myScroller.post( new Runnable() {
@Override
public void run() {
myScroller.smoothScrollTo( 0, myScroller.getChildAt( 0 ).getBottom() );
}
}
It took me much research and playing around to find this simple solution. I hope it helps you, too! :)
just page scroll:
ScrollView sv = (ScrollView) findViewById(your_scroll_view);
sv.pageScroll(View.FOCUS_DOWN);
I was using the Runnable with sv.fullScroll(View.FOCUS_DOWN); It works perfectly for the immediate problem, but that method makes ScrollView take the Focus from the entire screen, if you make that AutoScroll to happen every time, no EditText will be able to receive information from the user, my solution was use a different code under the runnable:
sv.scrollTo(0, sv.getBottom() + sv.getScrollY());
making the same without losing focus on important views
greetings.
it's working for me
mScrollView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
mScrollView.post(new Runnable() {
public void run() {
mScrollView.fullScroll(View.FOCUS_DOWN);
}
});
}
});
private int totalHeight = 0;
ViewTreeObserver ScrollTr = loutMain.getViewTreeObserver();
ScrollTr.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
loutMain.getViewTreeObserver().removeGlobalOnLayoutListener(this);
} else {
loutMain.getViewTreeObserver().removeOnGlobalLayoutListener(this);
}
TotalHeight = loutMain.getMeasuredHeight();
}
});
scrollMain.smoothScrollTo(0, totalHeight);
I had to create Interface
public interface ScrollViewListener {
void onScrollChanged(ScrollViewExt scrollView,
int x, int y, int oldx, int oldy);
}
import android.content.Context;
import android.util.AttributeSet;
import android.widget.ScrollView;
public class CustomScrollView extends ScrollView {
private ScrollViewListener scrollViewListener = null;
public ScrollViewExt(Context context) {
super(context);
}
public CustomScrollView (Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public CustomScrollView (Context context, AttributeSet attrs) {
super(context, attrs);
}
public void setScrollViewListener(ScrollViewListener scrollViewListener) {
this.scrollViewListener = scrollViewListener;
}
@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
if (scrollViewListener != null) {
scrollViewListener.onScrollChanged(this, l, t, oldl, oldt);
}
}
}
<"Your Package name ".CustomScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/scrollView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:focusableInTouchMode="true"
android:scrollbars="vertical">
private CustomScrollView scrollView;
scrollView = (CustomScrollView)mView.findViewById(R.id.scrollView);
scrollView.setScrollViewListener(this);
@Override
public void onScrollChanged(ScrollViewExt scrollView, int x, int y, int oldx, int oldy) {
// We take the last son in the scrollview
View view = (View) scrollView.getChildAt(scrollView.getChildCount() - 1);
int diff = (view.getBottom() - (scrollView.getHeight() + scrollView.getScrollY()));
// if diff is zero, then the bottom has been reached
if (diff == 0) {
// do stuff
//TODO keshav gers
pausePlayer();
videoFullScreenPlayer.setVisibility(View.GONE);
}
}
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