md-color 设置悬停颜色

Question

我正在使用 Angular Material 1.* 组件，对此我感到非常高兴。

我想像普通md-colors 背景一样使用主题颜色设置悬停状态背景，但找不到任何有关如何设置悬停状态颜色的文档。

有谁知道这是否可行以及怎么做？

Answer 1

我通过使用 md-colors 设置背景颜色并将其隐藏在另一个元素后面来创建一个解决方法。然后悬停状态使顶层透明，因此它看起来是一个动态设置的悬停状态！ 在此处查看此答案：

https://stackoverflow.com/a/46650109/4881971

Answer 2

如果你查看角度材质库的colors.js文件，你会发现没有让我们配置悬停效果状态的选项：

     /**
   * @ngdoc directive
   * @name mdColors
   * @module material.components.colors
   *
   * @restrict A
   *
   * @description
   * `mdColors` directive will apply the theme-based color expression as RGBA CSS style values.
   *
   *   The format will be similar to our color defining in the scss files:
   *
   *   ## `[?theme]-[palette]-[?hue]-[?opacity]`
   *   - [theme]    - default value is the default theme
   *   - [palette]  - can be either palette name or primary/accent/warn/background
   *   - [hue]      - default is 500 (hue-x can be used with primary/accent/warn/background)
   *   - [opacity]  - default is 1
   *
   *   > `?` indicates optional parameter
   *
   * @usage
   * <hljs lang="html">
   *   <div md-colors="{background: 'myTheme-accent-900-0.43'}">
   *     <div md-colors="{color: 'red-A100', 'border-color': 'primary-600'}">
   *       <span>Color demo</span>
   *     </div>
   *   </div>
   * </hljs>
   *
   * `mdColors` directive will automatically watch for changes in the expression if it recognizes an interpolation
   * expression or a function. For performance options, you can use `::` prefix to the `md-colors` expression
   * to indicate a one-time data binding.
   * <hljs lang="html">
   *   <md-card md-colors="::{background: '{{theme}}-primary-700'}">
   *   </md-card>
   * </hljs>
   *
   */
  function MdColorsDirective($mdColors, $mdUtil, $log, $parse) {
    return {
      restrict: 'A',
      require: ['^?mdTheme'],
      compile: function (tElem, tAttrs) {
        var shouldWatch = shouldColorsWatch();

        return function (scope, element, attrs, ctrl) {
          var mdThemeController = ctrl[0];

          var lastColors = {};

          var parseColors = function (theme) {
            if (typeof theme !== 'string') {
              theme = '';
            }

            if (!attrs.mdColors) {
              attrs.mdColors = '{}';
            }

            /**
             * Json.parse() does not work because the keys are not quoted;
             * use $parse to convert to a hash map
             */
            var colors = $parse(attrs.mdColors)(scope);

            /**
             * If mdTheme is defined up the DOM tree
             * we add mdTheme theme to colors who doesn't specified a theme
             *
             * # example
             * <hljs lang="html">
             *   <div md-theme="myTheme">
             *     <div md-colors="{background: 'primary-600'}">
             *       <span md-colors="{background: 'mySecondTheme-accent-200'}">Color demo</span>
             *     </div>
             *   </div>
             * </hljs>
             *
             * 'primary-600' will be 'myTheme-primary-600',
             * but 'mySecondTheme-accent-200' will stay the same cause it has a theme prefix
             */
            if (mdThemeController) {
              Object.keys(colors).forEach(function (prop) {
                var color = colors[prop];
                if (!$mdColors.hasTheme(color)) {
                  colors[prop] = (theme || mdThemeController.$mdTheme) + '-' + color;
                }
              });
            }

            cleanElement(colors);

            return colors;
          };

          var cleanElement = function (colors) {
            if (!angular.equals(colors, lastColors)) {
              var keys = Object.keys(lastColors);

              if (lastColors.background && !keys.color) {
                keys.push('color');
              }

              keys.forEach(function (key) {
                element.css(key, '');
              });
            }

            lastColors = colors;
          };

          /**
           * Registering for mgTheme changes and asking mdTheme controller run our callback whenever a theme changes
           */
          var unregisterChanges = angular.noop;

          if (mdThemeController) {
            unregisterChanges = mdThemeController.registerChanges(function (theme) {
              $mdColors.applyThemeColors(element, parseColors(theme));
            });
          }

          scope.$on('$destroy', function () {
            unregisterChanges();
          });

          try {
            if (shouldWatch) {
              scope.$watch(parseColors, angular.bind(this,
                $mdColors.applyThemeColors, element
              ), true);
            }
            else {
              $mdColors.applyThemeColors(element, parseColors());
            }

          }
          catch (e) {
            $log.error(e.message);
          }

        };

        function shouldColorsWatch() {
          // Simulate 1x binding and mark mdColorsWatch == false
          var rawColorExpression = tAttrs.mdColors;
          var bindOnce = rawColorExpression.indexOf('::') > -1;
          var isStatic = bindOnce ? true : STATIC_COLOR_EXPRESSION.test(tAttrs.mdColors);

          // Remove it for the postLink...
          tAttrs.mdColors = rawColorExpression.replace('::', '');

          var hasWatchAttr = angular.isDefined(tAttrs.mdColorsWatch);

          return (bindOnce || isStatic) ? false :
            hasWatchAttr ? $mdUtil.parseAttributeBoolean(tAttrs.mdColorsWatch) : true;
        }
      }
    };

  }

Answer 3

虽然css中不支持hover状态，但是可以用ng-mouseenter模拟，用angular来模拟mouseleave。

类似于这些指令的组合应用于元素：

md-colors="{backgroundColor: hover ? '{{$ctrl.theme}}-warn' : '{{$ctrl.theme}}-background'}"
ng-mouseenter="hover = true"
ng-mouseleave="hover = false"

其中 $ctrl.theme 是您当前主题的字符串。通过在 $scope 中注册 hover 属性，您可以将其用作颜色的控制，以在 md-colors 指令中传递。