Android中RecyclerView拖拽、侧删功能的实现代码

废话不多说，下面展示一下效果。

这是gridview主文件实现。

public class gridviewactivity extends appcompatactivity {
  recyclerview mrecyclerview;
  list<string> mstringlist;
  recycleradapter mrecyadapter;
  @override
  protected void oncreate(@nullable bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_recyclerview);
    initview();
    initrecy();
  }
  private void initview() {
    getsupportactionbar().setdisplayhomeasupenabled(true);
    mrecyclerview = (recyclerview) findviewbyid(r.id.view_recycler);
  }
  private void initrecy() {
    if (mstringlist == null) {
      mstringlist = new arraylist<>();
    }
    mstringlist.addall(datamanager.getdata(20 - mstringlist.size()));
    mrecyadapter = new recycleradapter(r.layout.item_gridview, mstringlist, true);
    mrecyclerview.setlayoutmanager(new gridlayoutmanager(this, 4));
    mrecyclerview.additemdecoration(new dividergriitemdecoration(this));
    mrecyclerview.sethasfixedsize(true);
    recyitemtouchhelpercallback itemtouchhelpercallback = new recyitemtouchhelpercallback(mrecyadapter, false, true);
    final itemtouchhelper itemtouchhelper = new itemtouchhelper(itemtouchhelpercallback);
    itemtouchhelper.attachtorecyclerview(mrecyclerview);
    mrecyclerview.addonitemtouchlistener(new onrecycleritemclicklistener(mrecyclerview) {
      @override
      public void onitemclick(recyclerview.viewholder viewholder) {
        recycleradapter.viewholder viewholder1 = (recycleradapter.viewholder) viewholder;
        string tvstring = viewholder1.mtextview.gettext().tostring();
        toast.maketext(gridviewactivity.this, "碰了一下 " + tvstring, toast.length_short).show();
      }
      @override
      public void onlongclick(recyclerview.viewholder viewholder) {
        recycleradapter.viewholder viewholder1 = (recycleradapter.viewholder) viewholder;
        string tvstring = viewholder1.mtextview.gettext().tostring();
        toast.maketext(gridviewactivity.this, "长按不放可以拖动！", toast.length_short).show();
        if (viewholder.getlayoutposition() != 0) {
          itemtouchhelper.startdrag(viewholder);
        }
      }
    });
    mrecyclerview.setadapter(mrecyadapter);
  }
  @override
  public boolean onoptionsitemselected(menuitem item) {
    if (item.getitemid() == android.r.id.home) {
      finish();
    }
    return super.onoptionsitemselected(item);
  }
}

代码不难理解，就是activity里面设置一大堆初始化的东西。recyclerview 初始化，setlayoutmanager、additemdecoration、sethasfixedsize、itemtouchhelper、addonitemtouchlistener、setadapter。拖拽效果关键代码是itemtouchhelper.startdrag(viewholder)。其他都围绕着它来转。

然后具体看看各个设置。

datamanager

public class datamanager {
  private static list<string> sstringlist = arrays.aslist("语文", "数学", "英语", "政治",
      "历史", "化学", "生物", "地理", "体育", "音乐");
  public static final list<string> getdata(int number) {
    list<string> stringlist = new arraylist<>();
    for (int i = 0; i < number; i++) {
      stringlist.add(sstringlist.get(i % sstringlist.size()));
    }
    return stringlist;
  }
}

dividergriitemdecoration 这个绘画了item的边线

public class dividergriitemdecoration extends recyclerview.itemdecoration {
  private static final int[] attrs = new int[]{android.r.attr.listdivider};
  private drawable mdivider;
  private int linewidth = 1;
  public dividergriitemdecoration(gridviewactivity gridviewactivity) {
    final typedarray array = gridviewactivity.obtainstyledattributes(attrs);
    mdivider = array.getdrawable(0);
    array.recycle();
  }
  public dividergriitemdecoration(int color) {
    mdivider = new colordrawable(color);
  }
  @override
  public void ondraw(canvas c, recyclerview parent, recyclerview.state state) {
    drawhorizontal(c, parent);
    drawvertical(c, parent);
  }
  private void drawhorizontal(canvas c, recyclerview parent) {
    int childcount = parent.getchildcount();
    for (int i = 0; i < childcount; i++) {
      final view child = parent.getchildat(i);
      final recyclerview.layoutparams params = (recyclerview.layoutparams) child.getlayoutparams();
      final int left = child.getleft() - params.leftmargin;
      final int right = child.getright() + params.rightmargin + linewidth;
      final int top = child.getbottom() + params.bottommargin;
      final int bottom = top + linewidth;
      mdivider.setbounds(left, top, right, bottom);
      mdivider.draw(c);
    }
  }
  private void drawvertical(canvas c, recyclerview parent) {
    final int childcount = parent.getchildcount();
    for (int i = 0; i < childcount; i++) {
      final view child = parent.getchildat(i);
      final recyclerview.layoutparams params = (recyclerview.layoutparams) child.getlayoutparams();
      final int top = child.gettop() - params.topmargin;
      final int bottom = child.getbottom() + params.bottommargin;
      final int left = child.getright() + params.rightmargin;
      final int right = left + linewidth;
      mdivider.setbounds(left, top, right, bottom);
      mdivider.draw(c);
    }
  }
  @override
  public void getitemoffsets(rect outrect, view view, recyclerview parent, recyclerview.state state) {
    outrect.set(0, 0, linewidth, linewidth);
  }
}

recycleradapter 适配器，和ui建立连接

public class recycleradapter extends recyclerview.adapter<recycleradapter.viewholder> {
  private int item_layout;
  private list<string> mdatalist;
  private list<integer> mints;
  private boolean isfirstspecial;
  public recycleradapter(int item_gridview, list<string> datalist, boolean isfisrtspecial) {
    this(item_gridview, datalist);
    this.isfirstspecial = isfisrtspecial;
  }
  public recycleradapter(int item_gridview, list<string> datalist) {
    this.item_layout = item_gridview;
    this.mdatalist = datalist;
    mints = arrays.aslist(r.mipmap.ic_launcher, r.mipmap.ic_launcher,
        r.mipmap.ic_launcher, r.mipmap.ic_launcher,
        r.mipmap.ic_launcher, r.mipmap.ic_launcher);
  }
  @override
  public viewholder oncreateviewholder(viewgroup parent, int viewtype) {
    view view = layoutinflater.from(parent.getcontext()).inflate(item_layout, parent, false);
    return new viewholder(view);
  }
  @override
  public void onbindviewholder(viewholder holder, int position) {
    string str = mdatalist.get(position);
    if (isfirstspecial && position == 0) {
      holder.itemview.setbackgroundcolor(color.ltgray);
      holder.mtextview.settext("不许动");
      holder.mimageview.setimageresource(r.mipmap.ic_launcher);
    } else {
      holder.itemview.setbackgroundcolor(color.white);
      holder.mtextview.settext(str);
      holder.mimageview.setimageresource(mints.get(position % mints.size()));
    }
  }
  @override
  public int getitemcount() {
    return mdatalist == null ? 0 : mdatalist.size();
  }
  public list<string> getdatalist() {
    return mdatalist;
  }
  class viewholder extends recyclerview.viewholder {
    textview mtextview;
    imageview mimageview;
    public viewholder(view itemview) {
      super(itemview);
      mtextview = itemview.findviewbyid(r.id.tv_item);
      mimageview = itemview.findviewbyid(r.id.img_item);
    }
  }
}

onrecycleritemclicklistener，点击事件 。我们借用手势工具类gesturedetectorcompat 来操作

public abstract class onrecycleritemclicklistener implements recyclerview.onitemtouchlistener{
  private gesturedetectorcompat mgesturedetectorcompat;
  private recyclerview mrecyclerview;
  public onrecycleritemclicklistener(recyclerview mrecyclerview) {
    this.mrecyclerview = mrecyclerview;
    mgesturedetectorcompat = new gesturedetectorcompat(mrecyclerview.getcontext(),
        new itemtouchhelpergesturelistener());
  }
  @override
  public boolean onintercepttouchevent(recyclerview rv, motionevent e) {
    mgesturedetectorcompat.ontouchevent(e);
    return false;
  }
  @override
  public void ontouchevent(recyclerview rv, motionevent e) {
    mgesturedetectorcompat.ontouchevent(e);
  }
  @override
  public void onrequestdisallowintercepttouchevent(boolean disallowintercept) {
  }
  //回调事件
  public abstract void onitemclick(recyclerview.viewholder viewholder);
  public abstract void onlongclick(recyclerview.viewholder viewholder);
  private class itemtouchhelpergesturelistener extends gesturedetector.simpleongesturelistener {
    @override
    public boolean onsingletapup(motionevent e) {
      view childviewunder = mrecyclerview.findchildviewunder(e.getx(), e.gety());
      if (childviewunder != null) {
        recyclerview.viewholder childviewholder = mrecyclerview.getchildviewholder(childviewunder);
        onitemclick(childviewholder);
      }
      return true;
    }
    @override
    public void onlongpress(motionevent e) {
      view childviewunder = mrecyclerview.findchildviewunder(e.getx(), e.gety());
      if (childviewunder != null) {
        recyclerview.viewholder childviewholder = mrecyclerview.getchildviewholder(childviewunder);
        onlongclick(childviewholder);
      }
    }
  }
}

recyitemtouchhelpercallback

public class recyitemtouchhelpercallback extends itemtouchhelper.callback {
  recyclerview.adapter madapter;
  boolean isswipeenable;
  boolean isfirstdragunable;
  public recyitemtouchhelpercallback(recyclerview.adapter madapter) {
    this.madapter = madapter;
    isswipeenable = true;
    isfirstdragunable = false;
  }
  public recyitemtouchhelpercallback(recyclerview.adapter madapter, boolean isswipeenable, boolean isfirstdragunable) {
    this.madapter = madapter;
    this.isswipeenable = isswipeenable;
    this.isfirstdragunable = isfirstdragunable;
  }
//  获取touch的响应方向
  @override
  public int getmovementflags(recyclerview recyclerview, recyclerview.viewholder viewholder) {
    if (recyclerview.getlayoutmanager() instanceof gridlayoutmanager) {//网格布局时候
      int dragflags = itemtouchhelper.up | itemtouchhelper.down |
          itemtouchhelper.left | itemtouchhelper.right;
      int swipeflags = 0;
      return makemovementflags(dragflags, swipeflags);
    } else {//list布局时候
      int dragflags = itemtouchhelper.up | itemtouchhelper.down;
      int swipeflags = itemtouchhelper.start | itemtouchhelper.end;
      return makemovementflags(dragflags, swipeflags);
    }
  }
  @override
  public boolean onmove(recyclerview recyclerview, recyclerview.viewholder viewholder, recyclerview.viewholder target) {
    int fromposition = viewholder.getadapterposition();
    int toposition = target.getadapterposition();
    if (isfirstdragunable && toposition == 0) {
      return false;
    }
    //重新更新排序
    if (fromposition < toposition) {
      for (int i = fromposition; i < toposition; i++) {
        collections.swap(((recycleradapter) madapter).getdatalist(), i, i + 1);
      }
    } else {
      for (int i = fromposition; i > toposition; i--) {
        collections.swap(((recycleradapter) madapter).getdatalist(), i, i - 1);
      }
    }
    //刷新
    madapter.notifyitemmoved(fromposition, toposition);
    return true;
  }
  /**
   * 侧滑删除后会回调的方法
   */
  @override
  public void onswiped(recyclerview.viewholder viewholder, int direction) {
    int adapterposition = viewholder.getadapterposition();
    madapter.notifyitemremoved(adapterposition);
    ((recycleradapter)madapter).getdatalist().remove(adapterposition);
  }
  @override
  public void onselectedchanged(recyclerview.viewholder viewholder, int actionstate) {
    if (actionstate != itemtouchhelper.action_state_idle) {
      viewholder.itemview.setbackgroundcolor(color.ltgray);
    }
    super.onselectedchanged(viewholder, actionstate);
  }
  @override
  public void clearview(recyclerview recyclerview, recyclerview.viewholder viewholder) {
    super.clearview(recyclerview, viewholder);
    viewholder.itemview.setbackgroundcolor(color.white);
  }
  @override
  public boolean islongpressdragenabled() {
    return !isfirstdragunable;
  }
  @override
  public boolean isitemviewswipeenabled() {
    return isswipeenable;
  }
}

下面是list的相关设置

同样，listview也是一顿初始化设置。

public class listviewactivity extends appcompatactivity {
  recyclerview mrecyclerview;
  list<string> mstringlist;
  recycleradapter mrecyadapter;
  @override
  protected void oncreate(@nullable bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_recyclerview);
    initview();
    initrecy();
  }
  private void initrecy() {
    if (mstringlist == null) {
      mstringlist = new arraylist<>();
    }
    mstringlist.addall(datamanager.getdata(15 - mstringlist.size()));
    mrecyadapter = new recycleradapter(r.layout.item_listview, mstringlist);
    mrecyclerview.setlayoutmanager(new linearlayoutmanager(this));
    mrecyclerview.additemdecoration(new dividerlistitemdecoration(this, linearlayoutmanager.vertical));
    mrecyclerview.sethasfixedsize(true);
    recyitemtouchhelpercallback itemtouchhelpercallback = new recyitemtouchhelpercallback(mrecyadapter);
    final itemtouchhelper itemtouchhelper = new itemtouchhelper(itemtouchhelpercallback);
    itemtouchhelper.attachtorecyclerview(mrecyclerview);
    mrecyclerview.addonitemtouchlistener(new onrecycleritemclicklistener(mrecyclerview) {
      @override
      public void onitemclick(recyclerview.viewholder viewholder) {
        recycleradapter.viewholder viewholder1 = (recycleradapter.viewholder) viewholder;
        string tvstring = viewholder1.mtextview.gettext().tostring();
        toast.maketext(listviewactivity.this, "碰了一下 " + tvstring, toast.length_short).show();
      }
      @override
      public void onlongclick(recyclerview.viewholder viewholder) {
        toast.maketext(listviewactivity.this, "长按不放可以拖动！", toast.length_short).show();
      }
    });
    mrecyclerview.setadapter(mrecyadapter);
  }
  private void initview() {
    getsupportactionbar().setdisplayhomeasupenabled(true);
    mrecyclerview = (recyclerview) findviewbyid(r.id.view_recycler);
  }
  @override
  public boolean onoptionsitemselected(menuitem item) {
    if (item.getitemid() == android.r.id.home) {
      finish();
    }
    return super.onoptionsitemselected(item);
  }
}

dividerlistitemdecoration

public class dividerlistitemdecoration extends recyclerview.itemdecoration {
  private static final int[] attrs = new int[] {android.r.attr.listdivider};
  public static final int horizontal_list = linearlayoutmanager.horizontal;
  public static final int vertical_list = linearlayoutmanager.vertical;
  private drawable mdivider;
  private int morientation;
  public dividerlistitemdecoration() {
    super();
  }
  public dividerlistitemdecoration(context context, int orientation) {
    final typedarray array = context.obtainstyledattributes(attrs);
    mdivider = array.getdrawable(0);
    array.recycle();
    this.morientation = orientation;
  }
  public dividerlistitemdecoration(context context, int orientation, int drawableid) {
    mdivider = contextcompat.getdrawable(context, drawableid);
    setorientation(orientation);
  }
  @override
  public void ondraw(canvas c, recyclerview parent, recyclerview.state state) {
    super.ondraw(c, parent, state);
  }
  @override
  public void ondrawover(canvas c, recyclerview parent, recyclerview.state state) {
    super.ondrawover(c, parent, state);
  }
  @override
  public void getitemoffsets(rect outrect, view view, recyclerview parent, recyclerview.state state) {
    if (morientation == vertical_list) {
      outrect.set(0, 0, 0, mdivider.getintrinsicheight());
    } else {
      outrect.set(0, 0, mdivider.getintrinsicwidth(), 0);
    }
    super.getitemoffsets(outrect, view, parent, state);
  }
  public void setorientation(int orientation) {
    if (orientation != horizontal_list && orientation != vertical_list) {
      throw new illegalargumentexception("invalid orientaion");
    }
    morientation = orientation;
  }
}

源码下载:http://download.csdn.net/download/loongago/9972876

总结

以上所述是小编给大家介绍的android中recyclerview拖拽、侧删功能的实现代码，希望对大家有所帮助