聊聊GridView实现拖拽排序及数据交互的问题
程序员文章站
2022-03-12 22:34:56
在研究项目中的一个效果的时候，查找资料过程中发现有人有这么一种需求，就是gridview在实现拖拽排序的基础上，如果是两个gridview之间实现拖拽效果，并要实现数据交互。一、效果图：实现这个效果需...
在研究项目中的一个效果的时候，查找资料过程中发现有人有这么一种需求，就是gridview在实现拖拽排序的基础上，如果是两个gridview之间实现拖拽效果，并要实现数据交互。
一、效果图：
实现这个效果需要考虑的事情：
① 这个ui整体的构建以及事件的传递
② 如何实现view的共享，穿过边界
二、实现思路：
对于单个gridview的拖拽效果实现是参考网上的一篇文章，很抱歉没能及时保存地址，所以这里就不贴了。
整体实现： 一个容器（dragchessview）里放置两个dragview(可拖拽排序item的view)，事件全部交给dragchessview去处理，然后由他去控制事件的分配和处理。在这个容器中还在这两个dragview上面覆盖一层framelayout，来放置要移动的那个view，然后根据手势去移动view。dragview里面进行view的动态交换以及数据交换。
三、实现代码：
1. dragchessview代码
public class dragchessview extends framelayout {
private gesturedetector detector;
/**
* 点击拖动
*/
public static final int drag_when_touch = 0;
/**
* 长按拖动
*/
public static final int drag_by_long_click = 1;
private int mdragmode = drag_when_touch;
private boolean hassenddragmsg = false;
private handler handler = new handler(new handler.callback() {
@override
public boolean handlemessage(message msg) {
switch (msg.what) {
case 0x123:
// 启动拖拽模式
isdragable = true;
// 根据点击的位置生成该位置上的view镜像
if (istouchintop(msg.arg2)) {
mdragtop.setcurrentdragposition(msg.arg1);
copyview(mdragtop);
} else {
mdragbottom.setcurrentdragposition(msg.arg1);
copyview(mdragbottom);
}
hassenddragmsg = false;
break;
default:
break;
}
return false;
}
});
private boolean isdragable = true;
private float[] lastlocation = null;
private view mcopyview;
private ontouchlistener l;
// 转交给gridview一些常用监听器
private adapterview.onitemlongclicklistener itemlongclicklistener;
private int mtoucharea = 0;
private view dragslider;
private point mmovepoint; // 记录移动走向，上到下，还是下到上
/**
* @param itemclicklistener
* @描述:item 转交给gridview一些常用监听器
*/
public void setonitemclicklistener(adapterview.onitemclicklistener itemclicklistener) {
mdragbottom.setonitemclicklistener(itemclicklistener);
}
/**
* 长按监听器自己触发,点击拖动模式不存在长按
*
* @param
*/
public void setonitemlongclicklistener(adapterview.onitemlongclicklistener itemlongclicklistener) {
this.itemlongclicklistener = itemlongclicklistener;
}
private boolean canaddviewwhendragchange = true;
private int mstartpoint;
private int start_drag_top = 0;
private int start_drag_bottom = 1;
/**
* 手势监听器,滚动和单击
*/
private gesturedetector.simpleongesturelistener simpleongesturelistener = new gesturedetector.simpleongesturelistener() {
@override
public boolean onscroll(motionevent e1, motionevent e2, float distancex, float distancey) {
if (hassenddragmsg) {
hassenddragmsg = false;
handler.removemessages(0x123);
}
if (isdragable && mcopyview != null) {
if (lastlocation == null && e1 != null) {
lastlocation = new float[]{e1.getrawx(), e1.getrawy()};
}
if (lastlocation == null)
lastlocation = new float[]{0, 0};
distancex = lastlocation[0] - e2.getrawx();
distancey = lastlocation[1] - e2.getrawy();
lastlocation[0] = e2.getrawx();
lastlocation[1] = e2.getrawy();
mcopyview.setx(mcopyview.getx() - distancex);
mcopyview.sety(mcopyview.gety() - distancey);
int to = eventtoposition(e2);
mcopyview.invalidate();
if (isdragintop()) {
if (isdragfrombottom()) {
if (isdragback(isdragintop())) { //针对已经进入bottom区域，但是又返回来的情况
mstartpoint = start_drag_bottom; //切换，保证移动过程中只执行一次
canaddviewwhendragchange = true;
}
if (canaddviewwhendragchange) {// 保证移动过程中，数据只有一次的添加
mdragtop.addswapview(mdragbottom.getswapdata());
mdragbottom.removeswapview();
canaddviewwhendragchange = false;
if (hideview != null)
hideview.setvisibility(visible);
}
if (mdragtop.isviewinitdone()) {
mdragtop.setcurrentdragposition(mdragtop.getgridchildcount() - 1);
hideview = mdragtop.getgridchildat(mdragtop.getcurrentdragposition());
if (hideview != null)
hideview.setvisibility(invisible);
mmovepoint = getdragviewcenterpoint(mdragtop);
}
}
if (mdragtop.isviewinitdone())
dragchangeposition(mdragtop, to);
} else {
if (isdragfromtop()) {
if (isdragback(isdragintop())) {
mstartpoint = start_drag_top;
canaddviewwhendragchange = true;
}
if (canaddviewwhendragchange) {
mdragbottom.addswapview(mdragtop.getswapdata());
mdragtop.removeswapview();
canaddviewwhendragchange = false;
if (hideview != null)
hideview.setvisibility(visible);
}
if (mdragbottom.isviewinitdone()) {
mdragbottom.setcurrentdragposition(mdragbottom.getgridchildcount() - 1);
hideview = mdragbottom.getgridchildat(mdragbottom.getcurrentdragposition());
if (hideview != null)
hideview.setvisibility(invisible);
log.e("mmovepoint", mmovepoint.x + "-----------" + mmovepoint.y);
mmovepoint = getdragviewcenterpoint(mdragbottom);
}
}
if (mdragbottom.isviewinitdone())
dragchangeposition(mdragbottom, to);
}
}
return true;
}
@override
public void onshowpress(motionevent e) {
/** 响应长按拖拽 */
if (mdragmode == drag_by_long_click) {
// 启动拖拽模式
// isdragable = true;
// 通知父控件不拦截我的事件
getparent().requestdisallowintercepttouchevent(true);
// 根据点击的位置生成该位置上的view镜像
int position = eventtoposition(e);
if (iscandragmove(istouchintop(e) ? mdragtop : mdragbottom, position)) {
// copyview(currentdragposition = position);
message msg = handler.obtainmessage(0x123, position, (int) e.gety());
// showpress本身大概需要170毫秒
handler.sendmessagedelayed(msg, draglongpresstime - 170);
mmovepoint = new point((int) e.getx(), (int) e.gety());
mstartpoint = istouchintop(e) ? start_drag_top : start_drag_bottom;
hassenddragmsg = true;
}
}
}
};
private boolean isdragback(boolean dragintop) {
return (dragintop && mstartpoint == start_drag_top) || (!dragintop && mstartpoint == start_drag_bottom);
}
private boolean isdragfromtop() {
if (mmovepoint != null && mdragtop != null) {
if ((mmovepoint.x > mdragtop.getx() && mmovepoint.x < (mdragtop.getx() + mdragtop.getwidth())) && (mmovepoint.y > mdragtop.gety() && mmovepoint.y < (mdragtop.gety() + mdragtop.getheight()))) {
return true;
}
}
return false;
}
private point getdragviewcenterpoint(dragview dragview) {
point result = new point();
if (dragview != null) {
int height = dragview.getheight();
int width = dragview.getwidth();
float x = dragview.getx();
float y = dragview.gety();
result.set((int) (x + width / 2), (int) (y + height / 2));
}
return result;
}
private boolean isdragfrombottom() {
if (mmovepoint != null && mdragbottom != null) {
if ((mmovepoint.x > mdragbottom.getx() && mmovepoint.x < (mdragbottom.getx() + mdragbottom.getwidth())) && (mmovepoint.y > mdragbottom.gety() && mmovepoint.y < (mdragbottom.gety() + mdragbottom.getheight()))) {
return true;
}
}
return false;
}
private boolean istouchintop(motionevent event) {
float y = event.gety();
return istouchintop(y);
}
private boolean istouchintop(float y) {
return y > mdragtop.gety() && y < (mdragtop.gety() + mdragtop.getheight());
}
private void dragchangeposition(dragview dragview, int to) {
if (to != dragview.getcurrentdragposition() && iscandragmove(dragview, to)) {
dragview.ondragpositionchange(dragview.getcurrentdragposition(), to);
}
}
private boolean iscandragmove(dragview dragview, int position) {
return position >= dragview.getheaddragposition() && position < dragview.getgridchildcount() - dragview.getfootdragposition();
}
private framelayout mdragframe;
private dragview mdragbottom;
private dragview mdragtop;
private view hideview;
private long draglongpresstime = 600;
public dragchessview(@nonnull context context) {
this(context, null);
}
public dragchessview(@nonnull context context, @nullable attributeset attrs) {
this(context, attrs, -1);
}
public dragchessview(@nonnull context context, @nullable attributeset attrs, int defstyleattr) {
super(context, attrs, defstyleattr);
init(attrs);
}
private void init(attributeset attrs) {
context context = getcontext();
detector = new gesturedetector(context, simpleongesturelistener);
detector.setislongpressenabled(false);
mdragframe = new framelayout(context);
dragslider = layoutinflater.from(context).inflate(r.layout.layout_drag_chess, this, false);
mdragtop = dragslider.findviewbyid(r.id.drag_top);
mdragbottom = dragslider.findviewbyid(r.id.drag_bottom);
addview(dragslider, -1, -1);
addview(mdragframe, -1, -1);
}
@override
public boolean ontouchevent(motionevent ev) {
if (l != null) {
l.ontouch(this, ev);
}
if (!isviewinitdone()) {
return false;
}
if (isdragable) {
handlescrollandcremirror(ev);
} else {
// 交给子控件自己处理
dispatchevent(istouchintop(ev) ? mdragtop : mdragbottom, ev);
}
// 处理拖动
detector.ontouchevent(ev);
if (ev.getaction() == motionevent.action_cancel || ev.getaction() == motionevent.action_up) {
lastlocation = null;
if (hassenddragmsg) {
hassenddragmsg = false;
handler.removemessages(0x123);
}
}
return true;
}
private void dispatchevent(dragview dragview, motionevent ev) {
dragview.dispatchevent(ev);
}
private boolean isdragintop() {
if (mcopyview == null)
return false;
return (mcopyview.gety() + mcopyview.getheight()) < (mdragtop.gety() + mdragtop.getbottom());
}
/**
* description :拦截所有事件
*/
@override
public boolean onintercepttouchevent(motionevent ev) {
return true;
}
/**
* 处理自动滚屏,和单击生成镜像
*/
private void handlescrollandcremirror(motionevent ev) {
switch (ev.getaction()) {
case motionevent.action_down:
// 通知父控件不拦截我的事件
getparent().requestdisallowintercepttouchevent(true);
// 根据点击的位置生成该位置上的view镜像
int position = eventtoposition(ev);
makecopyview(istouchintop(ev) ? mdragtop : mdragbottom, position);
break;
case motionevent.action_move:
getparent().requestdisallowintercepttouchevent(true);// 通知父控件不拦截我的事件
// 内容太多时,移动到边缘会自动滚动
decodescrollarea(isdragintop() ? mdragtop : mdragbottom, ev);
break;
case motionevent.action_cancel:
case motionevent.action_up:
if (hideview != null) {
hideview.setvisibility(view.visible);
if (ondragselectlistener != null) {
ondragselectlistener.onputdown(hideview);
}
}
mdragframe.removeallviews();
// mdragframe.scrollto(0, 0);
// isnotifybydragsort = true;
updateui(isdragintop() ? mdragtop : mdragbottom, ev);
mcopyview = null;
canaddviewwhendragchange = true;
// 放手时取消拖动排序模式
if (mdragmode == drag_by_long_click) {
isdragable = false;
}
break;
default:
break;
}
}
private void updateui(dragview dragview, motionevent ev) {
if (dragview.ishaspositionchange()) {
dragview.sethaspositionchange(false);
dragview.getadapter().notifydatasetchanged();
} else if (mdragmode == drag_by_long_click && itemlongclicklistener != null) {
dragview.onitemlongclick(itemlongclicklistener);
}
// 停止滚动
if (dragview.iscanscroll()) {
int scrollstates2 = dragview.decodetoucharea(ev);
if (scrollstates2 != 0) {
dragview.ontouchareachange(0);
mtoucharea = 0;
}
}
}
private void decodescrollarea(dragview dragview, motionevent ev) {
if (dragview.iscanscroll()) {
int toucharea = dragview.decodetoucharea(ev);
if (toucharea != mtoucharea) {
dragview.ontouchareachange(toucharea);
mtoucharea = toucharea;
}
}
}
private void makecopyview(dragview dragview, int position) {
if (position >= dragview.getheaddragposition() && position < dragview.getgridchildcount() - dragview.getfootdragposition()) {
dragview.setcurrentdragposition(position);
copyview(dragview);
}
}
/**
* 得到事件触发点, 摸到的是哪一个item
*/
public int eventtoposition(motionevent ev) {
if (ev != null) {
if (istouchintop(ev))
return mdragtop.eventtoposition(ev);
return mdragbottom.eventtoposition(ev);
}
return 0;
}
/**
* 复制一个镜像,并添加到透明层
*/
private void copyview(dragview dragview) {
// todo: 2018/4/2 创建可移动的 item
hideview = dragview.getgridchildat(dragview.getcurrentdragposition());
int realposition = dragview.getgridchildpos(hideview);
dragadapter adapter = dragview.getadapter();
if (!adapter.isusecopyview()) {
mcopyview = adapter.getview(realposition, mcopyview, mdragframe);
} else {
mcopyview = adapter.copyview(realposition, mcopyview, mdragframe);
}
hideview.setvisibility(view.invisible);
if (mcopyview.getparent() == null)
mdragframe.addview(mcopyview, dragview.getmcolwidth(), dragview.getmcolheight());
int[] l1 = new int[2];
int[] l2 = new int[2];
hideview.getlocationonscreen(l1);
mdragframe.getlocationonscreen(l2);
// mcopyview.setx(hideview.getleft());
// mcopyview.sety(hideview.gettop() - mcurrenty);
mcopyview.setx(l1[0] - l2[0]);
mcopyview.sety(l1[1] - l2[1]);
if (ondragselectlistener == null) {
mcopyview.setscalex(1.2f);
mcopyview.setscaley(1.2f);
} else {
ondragselectlistener.ondragselect(mcopyview);
}
}
private dragsortgridview.ondragselectlistener ondragselectlistener;
/**
* @描述:一个item view刚被拖拽和放下时起来生成镜像时调用.
*/
public void setondragselectlistener(dragsortgridview.ondragselectlistener ondragselectlistener) {
this.ondragselectlistener = ondragselectlistener;
}
/**
* @param mode int类型
* @描述:设置拖动的策略是点击还是长按
*/
public void setdragmodel(int mode) {
this.mdragmode = mode;
isdragable = mode == drag_when_touch;
}
public void setanimframe(listenframelayout mdragframe) {
this.mdragframe = mdragframe;
}
/**
* 设置长按需要用时
*
* @param time
*/
public void setdraglongpresstime(long time) {
draglongpresstime = time;
}
public void setbottomadapter(@notnull dragadapter adapter) {
mdragbottom.setadapter(adapter);
}
public boolean isviewinitdone() {
boolean result = mdragbottom.isviewinitdone();
if (mdragtop.getvisibility() == visible)
result &= mdragtop.isviewinitdone();
return result;
}
public void settopadapter(@notnull dragadapter adapter) {
mdragtop.setadapter(adapter);
}
}
2. dragview的实现：
public class dragview<t> extends framelayout {
private static final int tag_key = r.id.first;
private noscrollgridview mgridview;
private list<view> mchilds = new arraylist<view>();
protected int mnumcolumns = 3;
protected int mcolheight = 0;
protected int mcolwidth = 0;
protected int mchildcount = 0;
protected int mmaxheight = 0;
private boolean isviewinitdone = false;
private listenscrollview mscrollview;
private int mcurrenty = 0;
/**
* 自动滚屏的动画
*/
private valueanimator animator;
private dragadapter adapter;
private int headdragposition = 0;
private int footdragposition = 0;
private int currentdragposition = -1;
/**
* 是否有位置发生改变,否则不用重绘
*/
private boolean haspositionchange = false;
/**
* gridview能否滚动,是否内容太多
*/
private boolean canscroll = true;
/**
* 动画时间
*/
private static final long anim_during = 250;
private object swapedata;
public dragview(@nonnull context context) {
this(context, null);
}
public dragview(@nonnull context context, @nullable attributeset attrs) {
this(context, attrs, -1);
}
public dragview(@nonnull context context, @nullable attributeset attrs, int defstyleattr) {
super(context, attrs, defstyleattr);
init();
}
private void init() {
context context = getcontext();
mgridview = new noscrollgridview(context);
mgridview.setverticalscrollbarenabled(false);
mgridview.setstretchmode(gridview.stretch_column_width);
mgridview.setselector(new colordrawable());
// view的宽高之类必须在测量,布局,绘制一系列过程之后才能获取到
mgridview.getviewtreeobserver().addongloballayoutlistener(new viewtreeobserver.ongloballayoutlistener() {
@override
public void ongloballayout() {
if (mchilds.isempty()) {
for (int i = 0; i < mgridview.getchildcount(); i++) {
view view = mgridview.getchildat(i);
view.settag(tag_key, new int[]{0, 0});
view.clearanimation();
mchilds.add(view);
}
}
if (!mchilds.isempty()) {
mcolheight = mchilds.get(0).getheight();
}
mcolwidth = mgridview.getcolumnwidth();
if (mchildcount % mnumcolumns == 0) {
mmaxheight = mcolheight * mchildcount / mnumcolumns;
} else {
mmaxheight = mcolheight * (mchildcount / mnumcolumns + 1);
}
canscroll = mmaxheight - getheight() > 0;
// 告知事件处理,完成view加载,许多属性也已经初始化了
isviewinitdone = true;
}
});
mscrollview = new listenscrollview(context);
mgridview.setnumcolumns(mnumcolumns);
mscrollview.addview(mgridview, -1, -1);
addview(mscrollview, -1, -1);
}
private datasetobserver observer = new datasetobserver() {
@override
public void onchanged() {
mchildcount = adapter.getcount();
// 下列属性状态清除,才会在被调用notifydatasetchange时,在gridview测量布局完成后重新获取
mchilds.clear();
mcolheight = mcolwidth = mmaxheight = 0;
isviewinitdone = false;
}
@override
public void oninvalidated() {
mchildcount = adapter.getcount();
}
};
/**
* 控制自动滚屏的动画监听器.
*/
private valueanimator.animatorupdatelistener animupdatelistener = new valueanimator.animatorupdatelistener() {
@override
public void onanimationupdate(valueanimator animation) {
int targety = math.round((float) animation.getanimatedvalue());
if (targety < 0) {
targety = 0;
} else if (targety > mmaxheight - getheight()) {
targety = mmaxheight - getheight();
}
// mgridview.scrollto(0, targety);
mscrollview.smoothscrollto(0, targety);
// mcurrenty = targety;
}
};
public void setadapter(dragadapter adapter) {
if (this.adapter != null && observer != null) {
this.adapter.unregisterdatasetobserver(observer);
}
this.adapter = adapter;
mgridview.setadapter(adapter);
adapter.registerdatasetobserver(observer);
mchildcount = adapter.getcount();
}
/**
* @param from
* @param to
* @描述:动画效果移动view
*/
public void translateview(int from, int to) {
view view = mchilds.get(from);
int fromxvalue = ((int[]) view.gettag(tag_key))[0];
int fromyvalue = ((int[]) view.gettag(tag_key))[1];
int toxvalue = to % mnumcolumns - from % mnumcolumns + fromxvalue;
int toyvalue = to / mnumcolumns - from / mnumcolumns + fromyvalue;
animation animation = new translateanimation(1, fromxvalue, 1, toxvalue, 1, fromyvalue, 1, toyvalue);
animation.setduration(anim_during);
animation.setfillafter(true);
view.settag(tag_key, new int[]{toxvalue, toyvalue});
view.startanimation(animation);
}
/**
* @param from
* @param to
* @描述:拖动view使位置发生改变时
*/
public void ondragpositionchange(int from, int to) {
if (from > to) {
for (int i = to; i < from; i++) {
translateview(i, i + 1);
}
} else {
for (int i = to; i > from; i--) {
translateview(i, i - 1);
}
}
if (!haspositionchange) {
haspositionchange = true;
}
if ((from >= mchilds.size() || from < 0) || (to >= mchilds.size() || to < 0))
return;
adapter.ondatamodelmove(from, to);
view view = mchilds.remove(from);
mchilds.add(to, view);
currentdragposition = to;
}
/**
* @param scrollstates
* @描述:触摸区域改变,做相应处理,开始滚动或停止滚动
*/
public void ontouchareachange(int scrollstates) {
if (!canscroll) {
return;
}
if (animator != null) {
animator.removeupdatelistener(animupdatelistener);
}
if (scrollstates == 1) {// 从普通区域进入触发向上滚动的区域
int instance = mmaxheight - getheight() - mcurrenty;
animator = valueanimator.offloat(mcurrenty, mmaxheight - getheight());
animator.setduration((long) (instance / 0.5f));
animator.settarget(mgridview);
animator.addupdatelistener(animupdatelistener);
animator.start();
} else if (scrollstates == -1) {// 进入触发向下滚动的区域
animator = valueanimator.offloat(mcurrenty, 0);
animator.setduration((long) (mcurrenty / 0.5f));
animator.settarget(mgridview);
animator.addupdatelistener(animupdatelistener);
animator.start();
}
}
/**
* @param ev 事件
* @return 0中间区域, 1底部,-1顶部
* @描述: 检查当前触摸事件位于哪个区域, 顶部1/5可能触发下滚,底部1/5可能触发上滚
*/
public int decodetoucharea(motionevent ev) {
if (ev.gety() > (getheight() + gety()) * 4 / (double) 5) {
return 1;
} else if (ev.gety() < (getheight() + gety()) / (double) 5) {
return -1;
} else {
return 0;
}
}
public boolean isviewinitdone() {
return isviewinitdone;
}
/**
* 设置前几个item不可以改变位置
*/
public void setnopositionchangeitemcount(int count) {
headdragposition = count;
}
/**
* 设置后几个item不可以改变位置
*/
public void setfootnopositionchangeitemcount(int count) {
footdragposition = count;
}
public int getheaddragposition() {
return headdragposition;
}
public int getfootdragposition() {
return footdragposition;
}
public int getgridchildcount() {
return mchilds.size();
}
public view getgridchildat(int position) {
if (position < 0 || position >= mchilds.size())
return null;
return mchilds.get(position);
}
public int getgridchildpos(view view) {
return mgridview.indexofchild(view);
}
public void setcurrentdragposition(int currentdragposition) {
this.currentdragposition = currentdragposition;
}
public int getcurrentdragposition() {
return currentdragposition;
}
public int getmcolheight() {
return mcolheight;
}
public int getmcolwidth() {
return mcolwidth;
}
public dragadapter getadapter() {
return adapter;
}
public boolean ishaspositionchange() {
return haspositionchange;
}
public void sethaspositionchange(boolean haspositionchange) {
this.haspositionchange = haspositionchange;
}
public boolean iscanscroll() {
return canscroll;
}
public void setonitemclicklistener(adapterview.onitemclicklistener onitemclicklistener) {
mgridview.setonitemclicklistener(onitemclicklistener);
}
public void onitemlongclick(adapterview.onitemlongclicklistener itemlongclicklistener) {
itemlongclicklistener.onitemlongclick(mgridview, childat(currentdragposition), currentdragposition, 0);
}
public view childat(int index) {
return mgridview.getchildat(index);
}
public void dispatchevent(motionevent ev) {
if (canscroll)
mscrollview.dispatchtouchevent(ev);
else
mgridview.dispatchtouchevent(ev);
}
public int eventtoposition(motionevent ev) {
if (ev != null) {
int m = (int) ev.getx() / mcolwidth;
int n = (int) (ev.gety() - gety() + mcurrenty) / mcolheight;
int position = n * mnumcolumns + m;
if (position >= mchildcount) {
return mchildcount - 1;
} else {
return position;
}
}
return 0;
}
public void addswapview(object data) {
adapter.addnewdata(data);
}
public object getswapdata() {
return adapter.getswapdata(currentdragposition);
}
public void removeswapview() {
if (adapter != null) {
adapter.removedata(currentdragposition);
adapter.notifydatasetchanged();
}
}
class listenscrollview extends scrollview {
public listenscrollview(context context) {
super(context);
}
@override
protected void onscrollchanged(int l, int t, int oldl, int oldt) {
super.onscrollchanged(l, t, oldl, oldt);
mcurrenty = getscrolly();
}
}
class noscrollgridview extends gridview {
public noscrollgridview(context context) {
super(context);
}
/**
* @return
* @描述:兼容老版本的getcolumwidth
* @作者 [pwx273343] 2015年7月1日
*/
public int getcolumnwidth() {
return getwidth() / getnumcolumns();
}
public noscrollgridview(context context, attributeset attrs) {
super(context, attrs);
}
@override
protected void onmeasure(int widthmeasurespec, int heightmeasurespec) {
int mexpandspec = measurespec.makemeasurespec(integer.max_value >> 2, measurespec.at_most);
super.onmeasure(widthmeasurespec, mexpandspec);
}
}
}
3. dragadapter的代码：
public abstract class dragadapter extends baseadapter {
/**
* @param from
* @param to
* @描述:当从from排序被拖到to排序时的处理方式,请对相应的数据做处理。
*/
public abstract void ondatamodelmove(int from, int to);
/**
* 复制view使用的方法,默认直接使用getview方法获取
*
* @param position
* @param convertview
* @param parent
* @return
*/
public view copyview(int position, view convertview, viewgroup parent) {
return null;
}
/**
* 是否启用copyview方法
*
* @return true 使用copyview复制 false 使用getview直接获取镜像
*/
public boolean isusecopyview() {
return false;
}
public abstract object getswapdata(int position);
public abstract void removedata(int position);
public void addnewdata(object data) {
}
}
4.使用mainactivity:
class griddragshortactivity : appcompatactivity() {
override fun oncreate(savedinstancestate: bundle?) {
super.oncreate(savedinstancestate)
window.attributes.systemuivisibility = view.system_ui_flag_fullscreen or view.system_ui_flag_layout_fullscreen or view.system_ui_flag_immersive or view.system_ui_flag_hide_navigation
setcontentview(r.layout.activity_grid_drag_short)
//长按item响应该item的拖动排序,默认是触摸就开始拖动
drag_main.setdragmodel(dragsortgridview.drag_by_long_click)
//设置每行个数
// drag_main.numcolumns = 3
var arraylist = arraylist<string>()
var list = arraylist<string>()
for (i in 0..29) {
arraylist.add("" + i)
}
for (i in 0..29) {
list.add(('a' + i).tostring())
}
drag_main.setbottomadapter(customadapter(list, this))
drag_main.settopadapter(customadapter(arraylist, this))
}
}
布局：activity_main.xml
<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<linearlayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.mdzz.dragchessview
android:id="@+id/drag_main"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</linearlayout>
</relativelayout>
布局 layout_drag_chess.xml:
<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.chineseall.bookshelf.mdzz.dragview
android:id="@+id/drag_top"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:background="#ffffff" />
<textview
android:id="@+id/folder_title"
android:layout_width="match_parent"
android:layout_height="40dp"
android:background="#0586f9"
android:gravity="center"
android:text="@string/text"
android:textcolor="#ffffff"
android:textsize="18sp" />
<com.chineseall.bookshelf.mdzz.dragview
android:id="@+id/drag_bottom"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:background="#ffffff" />
</linearlayout>
在实际使用中，可以更据需要再去拓展使用，代码演变过程中的另一个效果，来看看，以它结束这篇：
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