最近做的一些小項目中，都有用到分頁，需要自己去搞。就把整個分頁實現整理下吧，方便自己也方便他人。

前臺

1.引入paging.js

//分頁，頁碼導航,要求參數為一個對象function createPageNav(opt) {  opt= opt || {};  var $container  = opt.$container     || null, //必需，頁碼容器，請確保這個容器只用來存放頁碼導航    pageCount  = Number(opt.pageCount)  || 0,  //必需，頁碼總數    currentNum  = Number(opt.currentNum) || 1,  //選填，當前頁碼    maxCommonLen = Number(opt.maxCommonLen)|| 10,  //選填，普通頁碼的最大個數    className = opt.className || "pagination",//選填，分頁類型：pagination或pager等    preText  = opt.preText  || "上一頁",   //選填，上一頁文字顯示，適用于只有前后頁按鈕的情況    nextText = opt.nextText  || "下一頁",   //選填，下一頁文字，同上    firstText = opt.firstText || "首頁",  lastText = opt.lastText  || "末頁",    hasFirstBtn = opt.hasFirstBtn  === false ? false : true,    hasLastBtn  = opt.hasLastBtn  === false ? false : true,    hasPreBtn  = opt.hasPreBtn   === false ? false : true,    hasNextBtn  = opt.hasNextBtn  === false ? false : true,    hasInput   = opt.hasInput   === false ? false : true,    hasCommonPage= opt.hasCommonPage === false ? false : true,//選填，是否存在普通頁    beforeFun = opt.beforeFun || null, //選填，頁碼跳轉前調用的函數，可通過返回false來阻止跳轉，可接收目標頁碼參數    afterFun = opt.afterFun || null, //選填，頁碼跳轉后調用的函數，可接收目標頁碼參數    noPageFun = opt.noPageFun || null; //選填，頁碼總數為0時調用的函數  //當前顯示的最小頁碼，用于計算起始頁碼，直接容器,當前頁，前，后，首，末，輸入框  var minNum=1,changeLen,$parent,$currentPage,$preBtn,$nextBtn,$firstBtn,$lastBtn,$input;  //容器  if (!$container || $container.length != 1){    console.log("分頁容器不存在或不正確");    return false;  }  //總頁數  if(pageCount <= 0){    if(noPageFun) noPageFun();    return false;  }  //當前頁  if (currentNum < 1) currentNum = 1;  else if (currentNum > pageCount) currentNum = pageCount;  //普通頁碼的最大個數，起始頁算法限制，不能小于3  if(maxCommonLen<3) maxCommonLen=3;  //跳轉頁響應長度，用于計算起始頁碼  if(maxCommonLen>=8) changeLen=3;  else if(maxCommonLen>=5) changeLen=2;  else changeLen=1;  $container.hide();  _initPageNav();  $container.show();  function _initPageNav(){    var initStr = [];    initStr.push('<nav><ul class="'+ className +'" onselectstart="return false">');    if(hasFirstBtn)initStr.push('<li class="first-page" value="1"><span>'+ firstText +'</span></li>');    if(hasPreBtn) initStr.push('<li class="pre-page" value="' + (currentNum - 1) + '"><span>'+ preText +'</span></li>');    if(hasNextBtn) initStr.push('<li class="next-page" value="' + (currentNum + 1) + '"><span>'+ nextText +'</span></li>');    if(hasLastBtn) initStr.push('<li class="last-page" value="' + pageCount + '"><span>'+ lastText +'</span></li>');    if(hasInput)        initStr.push('<div class="input-page-div">當前第<input type="text" maxlength="6" value="' + currentNum + '" />頁，共<span>'        + pageCount        + '</span>頁<button type="button" class="btn btn-xs input-btn-xs">確定</button></div>');    initStr.push('</ul></nav>');    $container.html(initStr.join(""));    //初始化變量    $parent=$container.children().children();    if(hasFirstBtn) $firstBtn = $parent.children("li.first-page");    if(hasPreBtn)  $preBtn  = $parent.children("li.pre-page");    if(hasNextBtn) $nextBtn = $parent.children("li.next-page");    if(hasLastBtn) $lastBtn = $parent.children("li.last-page");    if(hasInput){      $input = $parent.find("div.input-page-div>input");      $parent.find("div.input-page-div>button").click(function(){        _gotoPage($input.val());      });    }      //初始化功能按鈕    _buttonToggle(currentNum);    //生成普通頁碼    if(hasCommonPage) {      _createCommonPage(_computeStartNum(currentNum), currentNum);    }    //綁定點擊事件    $parent.on("click", "li",function () {      var $this=$(this);      if ($this.is("li") && $this.attr("value")){        if(!$this.hasClass("disabled") && !$this.hasClass("active")){          _gotoPage($this.attr("value"));        }      }    });  }  //跳轉到頁碼  function _gotoPage(targetNum) {    targetNum=_formatNum(targetNum);    if (targetNum == 0 || targetNum == currentNum) return false;    // 跳轉前回調函數    if (beforeFun && beforeFun(targetNum) === false) return false;    //修改值    currentNum=targetNum;    if(hasInput)  $input.val(targetNum);    if(hasPreBtn) $preBtn.attr("value", targetNum - 1);    if(hasNextBtn) $nextBtn.attr("value", targetNum + 1);    //修改功能按鈕的狀態    _buttonToggle(targetNum);    // 計算起始頁碼    if(hasCommonPage) {      var starNum = _computeStartNum(targetNum);      if (starNum == minNum) {// 要顯示的頁碼是相同的        $currentPage.removeClass("active");        $currentPage = $parent.children("li.commonPage").eq(targetNum - minNum).addClass("active");      }       else {// 需要刷新頁碼        _createCommonPage(starNum, targetNum);      }    }    // 跳轉后回調函數    if (afterFun) afterFun(targetNum);  }  //整理目標頁碼的值  function _formatNum(num){    num = Number(num);    if(isNaN(num)) num=0;    else if (num <= 0) num = 1;    else if (num > pageCount) num = pageCount;    return num;  }  //功能按鈕的開啟與關閉  function _buttonToggle(current){    if (current == 1) {      if(hasFirstBtn) $firstBtn.addClass("disabled");      if(hasPreBtn)  $preBtn.addClass("disabled");    }     else {      if(hasFirstBtn) $firstBtn.removeClass("disabled");      if(hasPreBtn)  $preBtn.removeClass("disabled");    }    if (current == pageCount) {      if(hasNextBtn) $nextBtn.addClass("disabled");      if(hasLastBtn) $lastBtn.addClass("disabled");    }    else {      if(hasNextBtn) $nextBtn.removeClass("disabled");      if(hasLastBtn) $lastBtn.removeClass("disabled");    }  }  //計算當前顯示的起始頁碼  function _computeStartNum(targetNum) {    var startNum;    if (pageCount <= maxCommonLen)      startNum = 1;    else {      if ((targetNum - minNum) >= (maxCommonLen-changeLen)) {//跳轉到靠后的頁碼        startNum = targetNum - changeLen;        if ((startNum + maxCommonLen-1) > pageCount) startNum = pageCount - (maxCommonLen-1);// 邊界修正      }       else if ((targetNum - minNum) <= (changeLen-1)) {//跳轉到靠前的頁碼        startNum = targetNum - (maxCommonLen-changeLen-1);        if (startNum <= 0) startNum = 1;// 邊界修正      }       else {// 不用改變頁碼        startNum = minNum;      }    }    return startNum;  }  //生成普通頁碼  function _createCommonPage(startNum, activeNum) {    var initStr = [];    for (var i = 1,pageNum=startNum; i <= pageCount && i <= maxCommonLen; i++ , pageNum++) {      initStr.push('<li class="commonPage" value="' + pageNum + '"><a href="javascript:" rel="external nofollow" >' + pageNum + '</a></li>');    }    $parent.hide();    $parent.children("li.commonPage").remove();    if(hasPreBtn) $preBtn.after(initStr.join(""));    else if(hasFirstBtn) $firstBtn.after(initStr.join(""));    else $parent.prepend(initStr.join(""));    minNum = startNum;    $currentPage = $parent.children("li.commonPage").eq(activeNum-startNum).addClass("active");    $parent.show();  }}