按钮不会改变可见性

Question

在我的表格中我有按钮只显示然后编辑是真的。现在我从另一个按钮设置编辑并出现问题。 View变得可编辑，这很棒。但按钮没有显示。怎么了？

这是我认为的一些代码。

<div ng-controller="MenuController" ng-init="edit=false" style="background:whitesmoke; border:1px solid lightgray; border-radius:5px; margin-top:0px; margin-bottom:5px; height:405px;">

  <button prevent-default ng-click="" class="btn btn-deufol btn-sm pull-right" style="width:150px;margin:2px;"><span class="glyphicon glyphicon-print"></span> Lieferschein drucken</button>
  <button prevent-default ng-click="" class="btn btn-deufol btn-sm pull-right" style="width:150px;margin:2px;"><span class="glyphicon glyphicon-print"></span> Auftrag drucken</button>
  <button prevent-default ng-click="edit=true" ng-show="!edit" name="BtnWork" id="BtnWork" class="btn btn-deufol btn-sm pull-right" style="width:150px;margin:2px;"><span class="glyphicon glyphicon-pencil"></span> Bearbeiten</button>
  <button prevent-default ng-click="resetData()" ng-show="edit" ng-model="BtnReset" id="BtnReset" e-form="textBtnForm" class="btn btn-danger btn-sm pull-right" style="width:150px;margin:2px;"><span class="glyphicon glyphicon-remove-circle"></span> Abbruch</button>
  <button prevent-default ng-click="saveData()" ng-show="edit" id="BtnUpdate" class="btn btn-success btn-sm pull-right" style="width:150px;margin:2px;"><span class="glyphicon glyphicon-ok-circle"></span> Speichern</button>

  <ul class="nav nav-tabs">
    <li class="active">
      <a data-target="#tab-one" data-toggle="tab"><i class="glyphicon glyphicon-list-alt"></i> Auftrag</a>
    </li>
    <li>
      <a data-target="#tab-two" data-toggle="tab"><i class="glyphicon glyphicon-book"></i> Dokumente</a>
    </li>
  </ul>


  <div class="tab-content css-form">
    <div id="tab-one" class="tab-pane active">
      <form name="InputForm" novalidate role="form" class="simple-form">
        <div ng-view class="table-responsive table-singleview" style="position:relative;background:whitesmoke;margin-top:0px;margin-bottom:0px;">
          <table border="0" style="width:100%; height:100%;">
            <tbody ng-controller="ContractsSingleViewController">
              <tr>
                <td style="width:8%;" align="left">Standort</td>
                <td style="width:25.3333%">
                  <div ng-controller="LocationsListController">
                    <span class="nullable">
                      <%--required--%>
                      <select placeholder="Standort" data-ng-model="myLocations" ng-disabled="!edit" ng-options="Plants._locationName for Plants in myLocationsList" style="width:281px;height:23px;background:whitesmoke;" class="ng-valid ng-dirty">
                        <option value="">{{myViewData.locationName}}</option>
                      </select>
                    </span>
                    <%--<span class="label label-danger" data-ng-show="myViewData.locationName.$error.required">Required!</span>--%>
                  </div>
                </td>
                .............
          </table>
          </tbody>
        </div>
      </form>
    </div>
    <%--Table one--%>

在我的角度代码中，我设置了edit = true，如此（片段）：

$scope.edit = false;

为什么这适用于我的桌子，但我的按钮没有？