Google Charts API根据控件选择更改颜色

Question

I have a google chart where I am trying to change the color based on the category control.

My chart is a histogram which should change color based on the selection in the programmaticDropdown. Part of my code is shown below:

    var dashboard = new google.visualization.Dashboard(
      document.getElementById('programmatic_dashboard_div'));


    programmaticDropdown = new google.visualization.ControlWrapper({
      'controlType': 'CategoryFilter',
      'containerId': 'programmatic_control_div',
      'options': {
        'filterColumnLabel': 'Type',
        'ui': {'allowMultiple': false},
      }
    });

   programmaticChart  = new google.visualization.ChartWrapper({
    'chartType': 'Histogram',
    'containerId': 'programmatic_chart_div',
    'options': {
      'title': 'Issues by Month',
      'legend': 'none',
      'height':400,
      'hAxis': { 
          'viewWindowMode':'explicit',
          'viewWindow':{
            'max':13,
            'min':0
          }
        }
    },
     'view': { 'columns': [0, 1] }
  });




  dashboard.bind(programmaticDropdown, programmaticChart);
  dashboard.draw(data);
}

Also, here is a link to the google chart controls documentation that has some UI information... can anyone help?

Thanks!!!

https://developers.google.com/chart/interactive/docs/gallery/controls?hl=en#controls-gallery

Answer 1

Solved it!!! To do this, I had to add an event listener and function to my code. See below.

google.visualization.events.addListener(programmaticDropdown, 'statechange', changeTitle);

function changeTitle () {
    var location = programmaticDropdown.getState().selectedValues[0];
    if (location == "CLOSED") {
        programmaticChart.setOption('colors', ['#e7711c']);
    } else if (location == "OPEN") {
        programmaticChart.setOption('colors', ['#ff0000']);
    }

    programmaticChart.draw();
}