html - 在 AngularJS 中查找颜色相对于另一种颜色的百分比

Question

我需要根据另一个 div 元素的颜色更改一个 div 元素的颜色。

例。

 <div style="background-color:{{color_primary}};">

在另一个 DIV 中，颜色应该是 color_primary 的 70%(浅色)

<div style="background-color:{{this color is 70% of color_primary}};">

我怎样才能实现它？提前致谢。

Answer 1

您可以通过将此百分比应用于每个 RGB 组件来完成此操作，类似于 SASS 和 LESS 助手的做法。那么，您可以使用它来修改 angularjs 应用程序中的颜色属性。

以下示例演示了我为此问题创建的简单 API 的用法，该 API 在彩色模块中作为服务公开。

Disclaimer, it's just a simple module to demonstrate how it can be done, it means I'm not catching all errors and exceptions that could be thrown. Regardless, it's a beautiful module and I'm very proud of it :{D

用法

angular.module('myApp', ['colorized'])    
    .controller('myController', function ($colors) {
        var $ctrl = this;

        $ctrl.myLightenColor = $colors.lighten('#000000', 50); // 50% gray        
    });

colorized 模块加上一个简单的例子:

// The module
(function() {
  angular.module('colorized', [])
    .service('$colors', function() {

      this.lighten = function(src, percent) {

        var src = normalizeColor(src);

        if (!percent) return src;

        var srcRGB = colorAsArray(src),
          // you may want to change it to keep a different
          // range, for example, the range between the actual
          // collor and the full white collor, it's up to you
          lightFactor = (255 * percent) / 100,
          newRGB = {
            r: limited(srcRGB.r + lightFactor, 255),
            g: limited(srcRGB.g + lightFactor, 255),
            b: limited(srcRGB.b + lightFactor, 255),
          };

        return [
          padRGBDigit(newRGB.r.toString(16)),
          padRGBDigit(newRGB.g.toString(16)),
          padRGBDigit(newRGB.b.toString(16))
        ].join('');
      }

      function normalizeColor(color) {
        if (color == undefined) color = '000000';
        if (color[0] == '#') color = color.substring(1);

        return color;
      }

      function colorAsArray(color) {
        return {
          r: parseInt(color.substring(0, 2), 16),
          g: parseInt(color.substring(2, 4), 16),
          b: parseInt(color.substring(4, 8), 16),
        };
      }

      function limited(value, limit) {
        return Math.ceil(value > limit ? limit : value);
      }

      function padRGBDigit(str) {
        return ('00' + str).slice(-2);
      }

    });
})();
// my app
(function() {
  angular.module('myApp', ['colorized'])
    .controller('myController', function($scope, $colors) {
      $scope.mySourceColor = '#000000';
      $scope.myPercentage = 50;
      $scope.myLightColor = function() {
        return '#' + $colors.lighten($scope.mySourceColor, $scope.myPercentage);
      };
    });

  angular.element(document).ready(function() {
    angular.bootstrap(document, ['myApp']);
  });
})();

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.8/angular.js"></script>
<div ng-controller="myController">
  <input type="color" ng-model="mySourceColor">
  <input ng-style="{'background-color': myLightColor()}" type="range" ng-model="myPercentage" min="0" max="100">
  <span>
  {{ myLightColor() }}
</span>
</div>