javascript - 条形图图例在 amchart javascript 中不起作用

Question

大家好，我正在使用 amcharts 条形图，它工作正常，但我正在尝试获取图例，但它没有正确出现在这里我粘贴了我尝试过的代码帮助!我需要带有国名的图例

代码

var chart = AmCharts.makeChart("chartdiv", {
    "theme": "light",
    "type": "serial",
	"startDuration": 2,
    "dataProvider": [{
        "country": "USA",
        "visits": 4025,
        "color": "#FF0F00"
    }, {
        "country": "China",
        "visits": 1882,
        "color": "#FF6600"
    }, {
        "country": "Japan",
        "visits": 1809,
        "color": "#FF9E01"
    }, {
        "country": "Germany",
        "visits": 1322,
        "color": "#FCD202"
    }, {
        "country": "UK",
        "visits": 1122,
        "color": "#F8FF01"
    }, {
        "country": "France",
        "visits": 1114,
        "color": "#B0DE09"
    }, {
        "country": "India",
        "visits": 984,
        "color": "#04D215"
    }, {
        "country": "Spain",
        "visits": 711,
        "color": "#0D8ECF"
    }, {
        "country": "Netherlands",
        "visits": 665,
        "color": "#0D52D1"
    }, {
        "country": "Russia",
        "visits": 580,
        "color": "#2A0CD0"
    }, {
        "country": "South Korea",
        "visits": 443,
        "color": "#8A0CCF"
    }, {
        "country": "Canada",
        "visits": 441,
        "color": "#CD0D74"
    }, {
        "country": "Brazil",
        "visits": 395,
        "color": "#754DEB"
    }, {
        "country": "Italy",
        "visits": 386,
        "color": "#DDDDDD"
    }, {
        "country": "Australia",
        "visits": 384,
        "color": "#999999"
    }, {
        "country": "Taiwan",
        "visits": 338,
        "color": "#333333"
    }, {
        "country": "Poland",
        "visits": 328,
        "color": "#000000"
    }],
    "valueAxes": [{
        "position": "left",
        "title": "Visitors"
    }],
    "graphs": [{
        "balloonText": "[[category]]: <b>[[value]]</b>",
        "fillColorsField": "color",
        "fillAlphas": 1,
        "lineAlpha": 0.1,
        "type": "column",
        "valueField": "visits"
    }],
    "depth3D": 20,
	"angle": 30,
    "chartCursor": {
        "categoryBalloonEnabled": false,
        "cursorAlpha": 0,
        "zoomable": false
    },
    "categoryField": "country",
    "categoryAxis": {
        "gridPosition": "start",
        "labelRotation": 90
    },
    "export": {
    	"enabled": true
     }

});

#chartdiv {
  width: 100%;
  height: 500px;
}										

<script src="https://www.amcharts.com/lib/3/amcharts.js"></script>
<script src="https://www.amcharts.com/lib/3/serial.js"></script>
<script src="https://www.amcharts.com/lib/3/plugins/export/export.min.js"></script>
<link rel="stylesheet" href="https://www.amcharts.com/lib/3/plugins/export/export.css" type="text/css" media="all" />
<script src="https://www.amcharts.com/lib/3/themes/light.js"></script>
<div id="chartdiv"></div>

Answer 1

图例基于 graph 对象，而不是类别/轴标签，这就是为什么您只能看到代码中所有列的一个标记。如果要为每一列生成图例标记，则必须使用图例的 data 创建自己的标记。大批。 AmCharts' knowledge base 中有一个插件可以自动为您执行此操作.

插件代码如下:

/*
  Plugin to generate legend markers based on category
  and fillColor/lineColor/color field from the chart data by using 
  the legend's custom data array. Also allows for toggling markers
  by completely removing/adding columns from the chart

  The plugin assumes there is  only one graph object. 
*/
AmCharts.addInitHandler(function(chart) { 

  //method to handle removing/adding columns when the marker is toggled
  function handleCustomMarkerToggle(legendEvent) {
      var dataProvider = legendEvent.chart.dataProvider;
      var itemIndex; //store the location of the removed item

      //Set a custom flag so that the dataUpdated event doesn't fire infinitely, in case you have
      //a dataUpdated event of your own
      legendEvent.chart.toggleLegend = true; 
      // The following toggles the markers on and off.
      // The only way to "hide" a column and reserved space on the axis is to remove it
      // completely from the dataProvider. You'll want to use the hidden flag as a means
      // to store/retrieve the object as needed and then sort it back to its original location
      // on the chart using the dataIdx property in the init handler
      if (undefined !== legendEvent.dataItem.hidden && legendEvent.dataItem.hidden) {
        legendEvent.dataItem.hidden = false;
        dataProvider.push(legendEvent.dataItem.storedObj);
        legendEvent.dataItem.storedObj = undefined;
        //re-sort the array by dataIdx so it comes back in the right order.
        dataProvider.sort(function(lhs, rhs) {
          return lhs.dataIdx - rhs.dataIdx;
        });
      } else {
        // toggle the marker off
        legendEvent.dataItem.hidden = true;
        //get the index of the data item from the data provider, using the 
        //dataIdx property.
        for (var i = 0; i < dataProvider.length; ++i) { 
          if (dataProvider[i].dataIdx === legendEvent.dataItem.dataIdx) {
            itemIndex = i;
            break;
          }
        }
        //store the object into the dataItem
        legendEvent.dataItem.storedObj = dataProvider[itemIndex];
        //remove it
        dataProvider.splice(itemIndex, 1);
      }
      legendEvent.chart.validateData(); //redraw the chart
  }

  //check if legend is enabled and custom generateFromData property
  //is set before running
  if (!chart.legend || !chart.legend.enabled || !chart.legend.generateFromData) {
    return;
  }

  var categoryField = chart.categoryField;
  var colorField = chart.graphs[0].lineColorField || chart.graphs[0].fillColorsField || chart.graphs[0].colorField;
  var legendData =  chart.dataProvider.map(function(data, idx) {
    var markerData = {
      "title": data[categoryField] + ": " + data[chart.graphs[0].valueField], 
      "color": data[colorField],
      "dataIdx": idx //store a copy of the index of where this appears in the dataProvider array for ease of removal/re-insertion
    };
    if (!markerData.color) {
      markerData.color = chart.graphs[0].lineColor;
    }
    data.dataIdx = idx; //also store it in the dataProvider object itself
    return markerData;
  });

  chart.legend.data = legendData;

  //make the markers toggleable
  chart.legend.switchable = true;
  chart.legend.addListener("clickMarker", handleCustomMarkerToggle);

}, ["serial"]);

//to use, set generateFromData: true in your legend

这是使用您的代码的实际示例:

/*
  Plugin to generate legend markers based on category
  and fillColor/lineColor/color field from the chart data by using 
  the legend's custom data array. Also allows for toggling markers
  by completely removing/adding columns from the chart
  
  The plugin assumes there is  only one graph object. 
*/
AmCharts.addInitHandler(function(chart) { 
  
  //method to handle removing/adding columns when the marker is toggled
  function handleCustomMarkerToggle(legendEvent) {
      var dataProvider = legendEvent.chart.dataProvider;
      var itemIndex; //store the location of the removed item

      //Set a custom flag so that the dataUpdated event doesn't fire infinitely, in case you have
      //a dataUpdated event of your own
      legendEvent.chart.toggleLegend = true; 
      // The following toggles the markers on and off.
      // The only way to "hide" a column and reserved space on the axis is to remove it
      // completely from the dataProvider. You'll want to use the hidden flag as a means
      // to store/retrieve the object as needed and then sort it back to its original location
      // on the chart using the dataIdx property in the init handler
      if (undefined !== legendEvent.dataItem.hidden && legendEvent.dataItem.hidden) {
        legendEvent.dataItem.hidden = false;
        dataProvider.push(legendEvent.dataItem.storedObj);
        legendEvent.dataItem.storedObj = undefined;
        //re-sort the array by dataIdx so it comes back in the right order.
        dataProvider.sort(function(lhs, rhs) {
          return lhs.dataIdx - rhs.dataIdx;
        });
      } else {
        // toggle the marker off
        legendEvent.dataItem.hidden = true;
        //get the index of the data item from the data provider, using the 
        //dataIdx property.
        for (var i = 0; i < dataProvider.length; ++i) { 
          if (dataProvider[i].dataIdx === legendEvent.dataItem.dataIdx) {
            itemIndex = i;
            break;
          }
        }
        //store the object into the dataItem
        legendEvent.dataItem.storedObj = dataProvider[itemIndex];
        //remove it
        dataProvider.splice(itemIndex, 1);
      }
      legendEvent.chart.validateData(); //redraw the chart
  }

  //check if legend is enabled and custom generateFromData property
  //is set before running
  if (!chart.legend || !chart.legend.enabled || !chart.legend.generateFromData) {
    return;
  }
  
  var categoryField = chart.categoryField;
  var colorField = chart.graphs[0].lineColorField || chart.graphs[0].fillColorsField || chart.graphs[0].colorField;
  var legendData =  chart.dataProvider.map(function(data, idx) {
    var markerData = {
      "title": data[categoryField] + ": " + data[chart.graphs[0].valueField], 
      "color": data[colorField],
      "dataIdx": idx //store a copy of the index of where this appears in the dataProvider array for ease of removal/re-insertion
    };
    if (!markerData.color) {
      markerData.color = chart.graphs[0].lineColor;
    }
    data.dataIdx = idx; //also store it in the dataProvider object itself
    return markerData;
  });
  
  chart.legend.data = legendData;
  
  //make the markers toggleable
  chart.legend.switchable = true;
  chart.legend.addListener("clickMarker", handleCustomMarkerToggle);
  
}, ["serial"]);

var chart = AmCharts.makeChart("chartdiv", {
  "theme": "light",
  "type": "serial",
  "startDuration": 2,
  "legend": { 
    "generateFromData": true //custom property for the plugin
  },
  "dataProvider": [{
    "country": "USA",
    "visits": 4025,
    "color": "#FF0F00"
  }, {
    "country": "China",
    "visits": 1882,
    "color": "#FF6600"
  }, {
    "country": "Japan",
    "visits": 1809,
    "color": "#FF9E01"
  }, {
    "country": "Germany",
    "visits": 1322,
    "color": "#FCD202"
  }, {
    "country": "UK",
    "visits": 1122,
    "color": "#F8FF01"
  }, {
    "country": "France",
    "visits": 1114,
    "color": "#B0DE09"
  }, {
    "country": "India",
    "visits": 984,
    "color": "#04D215"
  }, {
    "country": "Spain",
    "visits": 711,
    "color": "#0D8ECF"
  }, {
    "country": "Netherlands",
    "visits": 665,
    "color": "#0D52D1"
  }, {
    "country": "Russia",
    "visits": 580,
    "color": "#2A0CD0"
  }, {
    "country": "South Korea",
    "visits": 443,
    "color": "#8A0CCF"
  }, {
    "country": "Canada",
    "visits": 441,
    "color": "#CD0D74"
  }, {
    "country": "Brazil",
    "visits": 395,
    "color": "#754DEB"
  }, {
    "country": "Italy",
    "visits": 386,
    "color": "#DDDDDD"
  }, {
    "country": "Australia",
    "visits": 384,
    "color": "#999999"
  }, {
    "country": "Taiwan",
    "visits": 338,
    "color": "#333333"
  }, {
    "country": "Poland",
    "visits": 328,
    "color": "#000000"
  }],
  "valueAxes": [{
    "position": "left",
    "title": "Visitors"
  }],
  "graphs": [{
    "balloonText": "[[category]]: <b>[[value]]</b>",
    "fillColorsField": "color",
    "fillAlphas": 1,
    "lineAlpha": 0.1,
    "type": "column",
    "valueField": "visits"
  }],
  "depth3D": 20,
  "angle": 30,
  "chartCursor": {
    "categoryBalloonEnabled": false,
    "cursorAlpha": 0,
    "zoomable": false
  },
  "categoryField": "country",
  "categoryAxis": {
    "gridPosition": "start",
    "labelRotation": 90
  },
  "export": {
    "enabled": true
  }

});

#chartdiv {
  width: 100%;
  height: 500px;
}

<script src="https://www.amcharts.com/lib/3/amcharts.js"></script>
<script src="https://www.amcharts.com/lib/3/serial.js"></script>
<script src="https://www.amcharts.com/lib/3/plugins/export/export.min.js"></script>
<link rel="stylesheet" href="https://www.amcharts.com/lib/3/plugins/export/export.css" type="text/css" media="all" />
<script src="https://www.amcharts.com/lib/3/themes/light.js"></script>
<div id="chartdiv"></div>