AngularJS ng-repeat不會重新呈現轉發器（UI），也不會再次調用ng-init

Question

我對ng-init有一點疑問，實際上我有一些圖表。

1. 趨勢線在頂部
2. 下面的餅圖。
3. HTML表格如下。

在頁面加載我沒有顯示任何內容，但是一旦我第一次點擊特定按鈕，我的整個圖表和表格將顯示為http請求收到的數據。 但之后如果我點擊另一個按鈕並執行相同的http請求，那么它會更新趨勢線和表，但不會更新餅圖。 我的餅圖使用ng-init在下面的div中呈現，當我測試ng-init =“myFunction（index）”方法時，它不會在后續點擊中更新。

<form>
  <md-input-container>
    <label for="myInput">Search Division</label>
    <md-icon md-svg-icon="~/Content/myIcons/searchicon/ic_search_black_36px.svg"></md-icon>
    <input type="text" id="myInput" ng-model="searchDiv" md-autofocus>
  </md-input-container>
  <md-content ng-repeat="prod in listofProd | filter: searchDiv">
    <md-button class="md-whiteframe-1dp card" ng-click="generateChart(prod)" flex-sm="100" flex-gt-sm="100" flex-gt-md="100">
    {{prod}}
    </md-button>
  </md-content>
</form>

<div layout="row" layout-wrap>
  <div flex="25" style="width:1000px;height:300px; border: 1px solid skyblue;" ng-repeat="year in years track by $index" id="piechart{{$index}}" ng-init="myFunction($index)">
  </div>
</div>

這是我的ng-init函數的angularjs代碼。

(function () {
  'use strict'
  angular.module("GAiiNSApp").controller("ProdPerDash", ['$http', '$scope', '$log', function ($http, $scope, $log) {
    $scope.isLoading = false;
    $scope.hideme = true;
    var currentdate = new Date();
    var startdd = "01";
    var startmonth = "00";
    var lastyear = currentdate.getFullYear() - 3;
    var enddd = "31";
    var endmonth = "11";
    var endyear = currentdate.getFullYear();
    $scope.StartDate = new Date(lastyear, startmonth, startdd);
    $scope.EndDate = new Date(endyear, endmonth, enddd);
    $scope.Region = "Local";
    $scope.Country = "";
    $scope.ProductLineSelected = false;
    $scope.ButtonText = "CUSTOMIZE";

    $scope.clicked = false;
    $scope.Yes = function () {
      if (!$scope.clicked == true) {
        $scope.ButtonText = "CANCEL";
        $scope.clicked = true;
      }
      else {
        $scope.ButtonText = "CUSTOMIZE";
        $scope.clicked = false;
      }
    }
    $scope.alert = function (message) {
      $window.alert(message);
    }

    $scope.Regions = ["Export", "Local"];
    $http.get('/General/API/GetProductDivision').then(function (res) {
      $scope.listofProd = res.data;
    });
    $scope.selectedProduct = "";
    $scope.generateChart = function (prodname) {
      $scope.selectedProduct = prodname;
      $scope.isLoading = true;
      $http.get('/Marketing/MarketingAPI/ProdPerformance', {
        params: {
          StartDate: $scope.StartDate,
          EndDate: $scope.EndDate,
          ProductDivision: prodname,
          Division: $scope.Region,
          Area: $scope.Country
        }
      }).then(function (res) {
        var resArray = res.data;
        var trendarray = [];
        $scope.TableRecords = resArray;
        $scope.hideme = false;
        var json = resArray;
        // console.log("Array of Objects: " + JSON.stringify($scope.TableRecords));
        var groupedData = {};
        var result = [];
        resArray.forEach(function (item) {
          var year = item.SecuredYear;
          var value = item.ValueInDhs;
          if (groupedData.hasOwnProperty(year)) {
            groupedData[year] += value;
          } else {
            groupedData[year] = value;
          }
        });
        //Pie chart data starts here
        var years = [];
        json.forEach(function (obj) {
          if (years.indexOf(obj.SecuredYear) == -1)
            years.push(obj.SecuredYear);
        });
        //$scope.years = years;
        $scope.years = angular.copy(years);
        $scope.pichartsview = true;
        $scope.myFunction = function (index) {

          var data = [['Product', 'ValueInDhs']];
          json.forEach(function (obj) {
            if (obj.SecuredYear == years[index]) {
              data.push([String(obj.GroupName).trim(), obj.ValueInDhs]);
            }
          });
          $scope.displayChart(data, index);
        }
        $scope.displayChart = function (dataForChart, index) {
          var chartData = dataForChart;
          google.charts.load('current', { 'packages': ['corechart'] });
          google.charts.setOnLoadCallback(drawChartPie);
          function drawChartPie() {
            var data = google.visualization.arrayToDataTable(chartData);
            var options = {
              chartArea: { left: 10, top: 20, width: "80%", height: "80%" },
              legend: 'bottom',
              is3D: true,
              pieSliceText: 'percentage',
              pieSliceTextStyle: {
                fontSize: 8
              },
              title: $scope.selectedProduct + " - " + $scope.years[index]
            };
            var chart = new google.visualization.PieChart(document.getElementById('piechart' + index));
            $scope.$apply(function () {
              chart.draw(data, options);
            });
          }
        }
        //Pie chart data ends here
        for (var year in groupedData) {
          var tmp = {};
          tmp[year] = groupedData[year];
          result.push(tmp);
        }
        result.forEach(function (obj, index) {
          var key = Object.keys(obj)[0];
          trendarray.push([parseInt(key, 10), obj[key]]);
        });
        trendarray.splice(0, 0, [{ label: 'SecuredYear', type: 'number' }, { label: 'ValueInDhs', type: 'number' }]);
        google.charts.load('current', { 'packages': ['corechart'] });
        google.charts.setOnLoadCallback(drawChart);
        $scope.isLoading = false;
          function drawChart() {
            var data = google.visualization.arrayToDataTable(
              trendarray
              );
            var options = {
              legend: 'none',
              title: 'Product Performance Trendline - ' + $scope.selectedProduct + " - " + $scope.Region,
              hAxis: { title: 'Secured Year', format: '0' },
              vAxis: { title: 'Secured Value in DHS' },
              trendlines: {
                0: {
                  lineWidth: 5,
                  type: 'polynomial',
                  visibleInLegend: true,
                  color: 'green',
                }
              }
            };
            var chart = new google.visualization.ScatterChart(document.getElementById('chart_div2'));
            chart.draw(data, options);
          }
        })
    $scope.ProductLineSelected = true;
    };
  }]); //this is ctrl closing
})(); //this is function closing

Answer 1

從Angular 1.2 ，它有一個選項track by以防止轉發器重新渲染所有項目以提高性能。

更多信息請訪問： http ： //www.codelord.net/2014/04/15/improving-ng-repeat-performance-with-track-by/

這就是為什么ng-init在相同的years再次被解雇的原因，因為你已經在這里使用了track by ng-repeat="year in years track by $index" 。

即使你刪除它， ng-init也是第二次沒有被觸發，因為這里years是Angular非常強大的數組，它可以通過它的值進行跟蹤，盡管沒有明確的track by 。

因此，我們必須將years從簡單數組更改為object array如[{year: obj.SecuredYear}] ，讓Angular生成一個$$hashKey ，當對象每次更改時，它都不相同，而Angular將重繪轉發器通過觸發ng-init 。

所以與此相關的變化是，

HTML

<div flex="25" style="width:1000px;height:300px; border: 1px solid skyblue;" 
  ng-repeat="year in years" id="piechart{{$index}}" ng-init="myFunction($index)">
</div>

JS （填充years ）

    var years = [];
    json.forEach(function (obj) {
      var exists = years.filter(function(y) {
        return y.year === obj.SecuredYear;
      });

      if (exists.length === 0) { // This will replace the `indexOf` check
        years.push({year: obj.SecuredYear});  // change here
      }
    });
    $scope.years = years;

JS （myFunction（））

      $scope.myFunction = function (index) {
      var data = [['Product', 'ValueInDhs']];
      json.forEach(function (obj) {
        if (obj.SecuredYear == years[index].year) {   // change here at years[index].year
          data.push([String(obj.GroupName).trim(), obj.ValueInDhs]);
        }
      });
      $scope.displayChart(data, index);
    };

我剛剛創建了一個示例代碼段 ，如下所示，使用console.log(years[index].year); 在每次單擊“ Generate Chart ”按鈕時，使用ng-init成功記錄的$scope.myFunction()內部。

 angular.module('myApp', []); function MyCtrl($scope) { var json = [{SecuredYear: 1965},{SecuredYear: 1988}, {SecuredYear: 2016}, {SecuredYear: 2012}]; $scope.generateChart = function(item) { var years = []; json.forEach(function (obj) { var exists = years.filter(function(y) { return y.year === obj.SecuredYear; }); if (exists.length === 0) { years.push({year: obj.SecuredYear}); } }); $scope.years = years; $scope.myFunction = function (index) { var data = [['Product', 'ValueInDhs']]; json.forEach(function (obj) { if (obj.SecuredYear == years[index].year) { //data.push([String(obj.GroupName).trim(), obj.ValueInDhs]); console.log(years[index].year); } }); //$scope.displayChart(data, index); }; }; } 

 <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script> <div ng-app="myApp"> <div ng-controller="MyCtrl"> <button ng-click="generateChart()">Generate Chart</button><br/> <div style="border: 1px solid skyblue;" ng-repeat="year in years" id="piechart{{$index}}" ng-init="myFunction($index)" >{{year.year}} </div> </div> </div> 

Answer 2

 angular.module('app', [ 'googlechart' ]) .controller('appCtrl', function() { let vm = this; vm.charts = []; vm.addChart = function() { vm.charts.push({ type: "PieChart", data: { "cols": [{ id: "t", label: "Topping", type: "string" }, { id: "s", label: "Slices", type: "number" }], "rows": [{ c: [{ v: "Mushrooms" }, { v: 3 }, ] }, { c: [{ v: vm.input.name }, { v: vm.input.quantity }] }, { c: [{ v: "Olives" }, { v: 31 }] }, { c: [{ v: "Zucchini" }, { v: 1 }, ] }, { c: [{ v: "Pepperoni" }, { v: 2 }, ] }] } }); }; return vm; }); 

 <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.9/angular.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/angular-google-chart/0.1.0/ng-google-chart.min.js" type="text/javascript"></script> <div ng-app="app" ng-controller="appCtrl as vm"> <div ng-repeat="chart in vm.charts track by $index"> <div google-chart chart="chart" style="height:150px; width:100%;"></div> </div> <br> <input type="text" required ng-model="vm.input.name" placeholder="Enter name"> <input type="number" required ng-model="vm.input.quantity" placeholder="Enter quantity"> <button ng-click="vm.addChart()">Add chart</button> </div> 

我注意到你正在使用谷歌圖表。 您的問題來自於使用不兼容的庫（谷歌圖表不知道模型中的變化 - 在這種情況下是角度）。

你可以編寫自己的指令，但為什么如果其他人已經完成了繁重的工作？ 相反，我建議您考慮使用以下指令 。

這里有一個活例子。

編輯： ng-init 不能按您希望的方式工作。 ng-init只是在控制器加載時觸發一個函數，而不是在渲染元素時觸發。