【移動應(yīng)用開發(fā)技術(shù)】Android如何使用Scroller實現(xiàn)一個可向上滑動的底部導(dǎo)航欄

看下效果：/upload/information/20200623/125/128686.gifscrollTo(int,int)與scrollBy(int,int)Scroller類@Override

public

void

computeScroll()

{

if

(mSputeScrollOffset())

{

//

計算新位置，并判斷上一個滾動是否完成。

scrollTo(mScroller.getCurrX(),

mScroller.getCurrY());

invalidate();//

再次調(diào)用computeScroll。

}

}computeScrollOffset()<com.study.androidtest.BottomBar

android:orientation="vertical"

android:layout_alignParentBottom="true"

android:layout_width="match_parent"

android:layout_height="wrap_content">

<LinearLayout

android:background="@color/colorAccent"

android:layout_width="match_parent"

android:layout_height="50dp">

</LinearLayout>

<LinearLayout

android:background="@color/colorPrimaryDark"

android:layout_width="match_parent"

android:layout_height="200dp">

</LinearLayout>

</com.study.androidtest.BottomBar>/upload/information/20200623/125/128687.png

@Override

protected

void

onLayout(boolean

changed,

int

l,

int

t,

int

r,

int

b)

{

super.onLayout(changed,

l,

t,

r,

b);

bottomBar.layout(0,

getMeasuredHeight()

-

bottomBar.getMeasuredHeight(),

getMeasuredWidth(),

getMeasuredHeight());

bottomContent.layout(0,

getMeasuredHeight(),

getMeasuredWidth(),

bottomBar.getBottom()

+

bottomContent.getMeasuredHeight());

}@Override

public

boolean

onTouchEvent(MotionEvent

event)

{

super.onTouchEvent(event);

switch

(event.getAction()){

case

MotionEvent.ACTION_DOWN:

Log.i("",

">x="+event.getX()

+

",

y="+event.getY());

downX

=

(int)

event.getX();

downY

=

(int)

event.getY();

break;

case

MotionEvent.ACTION_MOVE:

int

endY

=

(int)

event.getY();

int

dy

=

(int)

(endY

-

downY);

int

toScroll

=

getScrollY()

-

dy;

if(toScroll

<

0){

toScroll

=

0;

}

else

if(toScroll

>

bottomContent.getMeasuredHeight()){

toScroll

=

bottomContent.getMeasuredHeight();

}

scrollTo(0,

toScroll);

downY

=

(int)

event.getY();

break;

case

MotionEvent.ACTION_UP:

scrollOffset

=

getScrollY();

if(scrollOffset

>

bottomContent.getMeasuredHeight()

/

2){

showNavigation();

}

else

{

closeNavigation();

}

break;

}

return

true;

}

private

void

showNavigation(){

int

dy

=

bottomContent.getMeasuredHeight()

-

scrollOffset;

mScroller.startScroll(getScrollX(),

getScrollY(),

0,

dy,

500);

invalidate();

}

private

void

close