【移动应用开发技术】android ItemTouchHelper如何实现可拖拽和侧滑的列表

【移动应用开发技术】androidItemTouchHelper如何实现可拖拽和侧滑的列表

/upload/information/20200623/125/124115.gif实现基本功能布局文件<?xml

version="1.0"

encoding="utf-8"?>

<LinearLayout

xmlns:android="/apk/res/android"

android:layout_width="match_parent"

android:layout_height="match_parent">

<android.support.v7.widget.RecyclerView

android:layout_width="match_parent"

android:layout_height="match_parent"

android:id="@+id/main_recyclerView"

android:scrollbars="none"

android:background="#F2F8FC">

</android.support.v7.widget.RecyclerView>

</LinearLayout><?xml

version="1.0"

encoding="utf-8"?>

<android.support.constraint.ConstraintLayout

xmlns:android="/apk/res/android"

xmlns:app="/apk/res-auto"

android:layout_width="match_parent"

android:layout_height="60dp"

android:background="#ffffff">

<ImageView

android:id="@+id/item_list_menu_imageView"

android:layout_width="30dp"

android:layout_height="25dp"

android:layout_marginBottom="8dp"

android:layout_marginStart="15dp"

android:layout_marginTop="8dp"

android:src="@drawable/imageview_menu"

app:layout_constraintBottom_toBottomOf="parent"

app:layout_constraintStart_toStartOf="parent"

app:layout_constraintTop_toTopOf="parent"

/>

<TextView

android:id="@+id/item_list_text_textView"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_marginBottom="8dp"

android:layout_marginStart="15dp"

android:layout_marginTop="8dp"

android:textColor="#000000"

android:textSize="18sp"

app:layout_constraintBottom_toBottomOf="parent"

app:layout_constraintStart_toEndOf="@+id/item_list_menu_imageView"

app:layout_constraintTop_toTopOf="parent"/>

<android.support.v7.widget.SwitchCompat

android:id="@+id/item_list_switchCompat"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_marginBottom="8dp"

android:layout_marginEnd="15dp"

android:layout_marginTop="8dp"

app:layout_constraintBottom_toBottomOf="parent"

app:layout_constraintEnd_toEndOf="parent"

app:layout_constraintTop_toTopOf="parent"

/>

</android.support.constraint.ConstraintLayout>ItemTouchHelperpublic

interface

IItemTouchHelperAdapter

{

/**

*

当item被移动时调用

*

*

@param

fromPosition

被操作的item的起点

*

@param

toPosition

被操作的item的终点

*/

void

onItemMove(int

fromPosition,

int

toPosition);

/**

*

当item被侧滑时调用

*

*

@param

position

被侧滑的item的position

*/

void

onItemDismiss(int

position);

}

@Override

public

void

onItemMove(int

fromPosition,

int

toPosition)

{

Collections.swap(mList,

fromPosition,

toPosition);

notifyItemMoved(fromPosition,

toPosition);

}

@Override

public

void

onItemDismiss(int

position)

{

mList.remove(position);

notifyItemRemoved(position);

}public

class

MyItemTouchHelperCallback

extends

ItemTouchHelper.Callback

{

private

IItemTouchHelperAdapter

mAdapter;

public

MyItemTouchHelperCallback(IItemTouchHelperAdapter

mAdapter)

{

this.mAdapter

=

mAdapter;

}

@Override

public

int

getMovementFlags(RecyclerView

recyclerView,

RecyclerView.ViewHolder

viewHolder)

{

//上下拖拽，若有其他需求同理

int

dragFlags

=

ItemTouchHelper.UP

|

ItemTouchHelper.DOWN;

//向右侧滑，若有其他需求同理

int

swipeFlags

=

ItemTouchHelper.RIGHT;

return

makeMovementFlags(dragFlags,

swipeFlags);

}

@Override

public

boolean

onMove(RecyclerView

recyclerView,

RecyclerView.ViewHolder

viewHolder,

RecyclerView.ViewHolder

target)

{

//通知Adapter更新数据和视图

mAdapter.onItemMove(viewHolder.getAdapterPosition(),

target.getAdapterPosition());

//若返回false则表示不支持上下拖拽

return

true;

}

@Override

public

void

onSwiped(RecyclerView.ViewHolder

viewHolder,

int

direction)

{

//通知Adapter更新数据和视图

mAdapter.onItemDismiss(viewHolder.getAdapterPosition());

}

@Override

public

boolean

isItemViewSwipeEnabled()

{

//是否可以左右侧滑，默认返回true

return

true;

}

@Override

public

boolean

isLongPressDragEnabled()

{

//是否可以长按上下拖拽，默认返回false

return

true;

}

}mItemTouchHelper

=

new

ItemTouchHelper(new

MyItemTouchHelperCallback(adapter));

mItemTouchHelper.attachToRecyclerView(recyclerView);/upload/information/20200623/125/124116.gif完善通过按住item左边按钮才能上下拖拽@Override

public

boolean

isLongPressDragEnabled()

{

//禁止长按item可以上下拖拽，因为我们要自定义开启拖拽的时机

return

false;

}public

interface

OnStartDragListener

{

/**

*

当View需要拖拽时回调

*

*

@param

viewHolder

The

holder

of

view

to

drag

*/

void

onStartDrag(RecyclerView.ViewHolder

viewHolder);

}@Override

public

void

onStartDrag(RecyclerView.ViewHolder

viewHolder)

{

//通知ItemTouchHelper开始拖拽

mItemTouchHelper.startDrag(viewHolder);

}public

class

RecyclerViewAdapter

extends

RecyclerView.Adapter<RecyclerViewAdapter.IItemViewHolder>

implements

IItemTouchHelperAdapter

{

//构造方法

public

RecyclerViewAdapter(List<ItemEntity>

list,

OnStartDragListener

mDragListener)

{

mList

=

list;

this.mDragListener

=

mDragListener;

}

...

@Override

public

void

onBindViewHolder(final

IItemViewHolder

holder,

@SuppressLint("RecyclerView")

final

int

position)

{

...

holder.menu.setOnTouchListener(new

View.OnTouchListener()

{

@Override

public

boolean

onTouch(View

view,

MotionEvent

motionEvent)

{

if

(motionEvent.getAction()

==

MotionEvent.ACTION_DOWN)

{

//通知ItemTouchHelper开始拖拽

mDragListener.onStartDrag(holder);

}

return

false;

}

});

}

...

}public

interface

IItemTouchHelperViewHolder

{

/**

*

item被选中，在侧滑或拖拽过程中更新状态

*/

void

onItemSelected();

/**

*

item的拖拽或侧滑结束，恢复默认的状态

*/

void

onItemClear();

}

class

ItemViewHolder

extends

RecyclerView.ViewHolder

implements

IItemTouchHelperViewHolder

{

private

TextView

text;

private

ImageView

menu;

private

SwitchCompat

switchCompat;

ItemViewHolder(View

itemView)

{

super(itemView);

text

=

itemView.findViewById(R.id.item_list_text_textView);

menu

=

itemView.findViewById(R.id.item_list_menu_imageView);

switchCompat

=

itemView.findViewById(R.id.item_list_switchCompat);

}

@Override

public

void

onItemSelected()

{

itemView.setTranslationZ(10);

}

@Override

public

void

onItemClear()

{

itemView.setTranslationZ(0);

}

}

@Override

public

void

onSelectedChanged(RecyclerView.ViewHolder

viewHolder,

int

actionState)

{

if

(actionState

!=

ItemTouchHelper.ACTION_ST