android实现按钮获取焦点延迟加载

看到京东电视app的按钮获取焦点后才加载数据，之前网上没找到好的说法，所以自己实现了记录一下以便后续学习。

主要是按钮获取焦点以后，初始化一个定时器timer延迟500ms加载数据，如果失去焦点，取消这个定时器就ok了。其实原理很简单，下面是我实现的一个效果。

package com.longmaster.iptv.health.doctorp2p.mode;

import android.content.context;
import android.support.v7.widget.linearlayoutmanager;
import android.support.v7.widget.recyclerview;
import android.view.keyevent;
import android.view.layoutinflater;
import android.view.view;
import android.view.viewgroup;
import android.widget.linearlayout;
import android.widget.relativelayout;

import com.longmaster.iptv.health.r;
import com.longmaster.iptv.health.common.constants;
import com.longmaster.iptv.health.widget.magictextview.magictextview;

import org.videowebinterface.departmentparam;

import java.util.arraylist;
import java.util.list;
import java.util.timer;
import java.util.timertask;

import cn.longmaster.lmkit.event.messageproxy;
import cn.longmaster.lmkit.utils.applogger;


/**
 * created by yzq on 2017/5/8
 */

public class buttonadapter extends recyclerview.adapter<buttonadapter.myviewholder> {
  private list<departmentparam> mdepartmentlist = new arraylist<>();
  private layoutinflater minflater;
  private context mcontext;
  private boolean mislostfocus = false;
  private linearlayoutmanager mlinearlayoutmanager;
  private recyclerview mrecyclerview;
  private timertask mtimertask;
  private timer mtimer;
  private boolean isloaddata = true;

  public buttonadapter(context context) {
    super();
    this.mcontext = context;
    minflater = layoutinflater.from(context);
  }

  public void setlayoutmanager(linearlayoutmanager linearlayoutmanager, recyclerview re) {
    mlinearlayoutmanager = linearlayoutmanager;
    mrecyclerview = re;
  }

  public void setdepartmentlist(list list) {
    mdepartmentlist = list;
  }

  public void setfocus(boolean isfocus) {
    mislostfocus = isfocus;
  }

  public void setisloaddata(boolean isloaddata) {
    this.isloaddata = isloaddata;
  }

  public void clear() {
    mdepartmentlist.clear();
  }

  @override
  public int getitemcount() {
    return mdepartmentlist.size();
  }

  @override
  public void onbindviewholder(final myviewholder holder, final int position) {
    holder.tv.settext(mdepartmentlist.get(position).getdeptname());
    holder.tv.setfocusable(true);
  }

  @override
  public myviewholder oncreateviewholder(viewgroup parent, int viewtype) {
    view view = minflater.inflate(r.layout.list_class_item, parent, false);
    myviewholder holder = new myviewholder(view);
    return holder;
  }


  class myviewholder extends recyclerview.viewholder {

    magictextview tv;
    relativelayout mouterbgrl;

    public myviewholder(final view view) {
      super(view);
      recyclerview.layoutparams param = (recyclerview.layoutparams) itemview.getlayoutparams();
      param.height = linearlayout.layoutparams.wrap_content;
      param.width = linearlayout.layoutparams.match_parent;
      itemview.setvisibility(view.visible);

      tv = (magictextview) view.findviewbyid(r.id.class_name);
      mouterbgrl = (relativelayout) view.findviewbyid(r.id.rl_class_outer_bg);

      tv.setonfocuschangelistener(new view.onfocuschangelistener() {
        @override
        public void onfocuschange(view v, boolean hasfocus) {
          if (hasfocus) {
            mouterbgrl.setbackgroundresource(r.drawable.p2p_select);

            if (isloaddata) {
              mtimertask = new timertask() {
                @override
                public void run() {
                  int iposition = getadapterposition();
                  departmentparam departmentparam = mdepartmentlist.get(iposition);
                  messageproxy.sendmessage(constants.message.p2p_selection_doctor_class, iposition, departmentparam);
                }
              };
              mtimer = new timer();
              mtimer.schedule(mtimertask, 500);
            }

          } else {

            cleartimer();

            if (mislostfocus) {
              mouterbgrl.setbackgroundresource(r.drawable.p2p_unselect);
            }
            
          }
        }
      });
      tv.setonkeylistener(new view.onkeylistener() {
        @override
        public boolean onkey(view v, int keycode, keyevent event) {

          if (event.getaction() == keyevent.action_down) {
            int mcurrentselectposition = getadapterposition();
            int mdepartmentcount = mdepartmentlist.size();
            applogger.e("mcurrentselectposition>>>>>>>>", mcurrentselectposition + "----" + mdepartmentcount);
            switch (keycode) {
              case keyevent.keycode_dpad_left:

                setisloaddata(true);
                setfocus(true);

                if (mcurrentselectposition == (mlinearlayoutmanager.findfirstvisibleitemposition())) {
                  mrecyclerview.smoothscrollby(-400, 0);
                }

                view view1 = mlinearlayoutmanager.findviewbyposition(mcurrentselectposition - 1);

                if (view1 != null) {
                  setviewfocus(view1.findviewbyid(r.id.class_name));
                }

                return true;
              case keyevent.keycode_dpad_right:


                if (mcurrentselectposition == mdepartmentcount - 1) {
                  return true;
                }

                setisloaddata(true);
                setfocus(true);

                if (mcurrentselectposition == (mlinearlayoutmanager.findlastvisibleitemposition())) {
                  mrecyclerview.smoothscrollby(400, 0);
                }

                view view = mlinearlayoutmanager.findviewbyposition(mcurrentselectposition + 1);

                if (view != null) {
                  setviewfocus(view.findviewbyid(r.id.class_name));
                }

                return true;

              case keyevent.keycode_back:
                break;
              case keyevent.keycode_dpad_up:
                break;
              case keyevent.keycode_dpad_down:
                setfocus(false);
                mouterbgrl.setbackgroundresource(r.drawable.p2p_key_down);

                break;
            }
          }
          return false;
        }
      });
    }

  }

  public void setviewfocus(view view) {
    view.setfocusable(true);
    view.setfocusableintouchmode(true);
    view.requestfocus();
    view.requestfocusfromtouch();
  }

  private void cleartimer() {
    if (mtimer != null) {
      mtimer.cancel();
    }
    if (mtimertask != null) {
      mtimertask.cancel();
    }

  }

}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。