你要找的过滤器是widget_text. 从Codex:

widget_text
应用于WordPress文本小部件的小部件文本。也可能适用于某些第三方小部件。

下面的代码将允许您在所有小部件中，在其$实例数组中存在的所有字符串上进行替换。

// Hook into \'widget_display_callback\' filter
// It allows altering a Widget properties right before it outputs in sidebar
add_filter(\'widget_display_callback\', function($instance, $widget, $args){
    // Recursive functions that applies replacements in all string elements of $instance
    $fnFixArray = function($v) use (&$fnFixArray){
        // Dig deeper if this is an array or object
        if(is_array($v) or is_object($v)){
            // Use pointer here for property to satisfy both array/object in one
            // Otherwise for arrays we need $v[$k1] and $v->{$k1} for objects
            foreach($v as $k1=>&$v1){
                // Go recursive on elements / properties
                $v1 = $fnFixArray(v1);
            }
            return $v;
        }
        // Don\'t alter non-strings or empty ones
        if(!is_string($v) or empty($v)) return $v;
        // We found a string, replace stuff in it and return the altered value
        return str_replace(\'%REPLACEWHAT%\', \'%REPLACEWITH%\', $v);
    };
    return $fnFixArray($instance);
}, 11, 3); // We need 3 arguments and a below normal priority

It\'s a bit more advanced but it\'s WHAT you really need.

// Hook into the \'widget_display_callback\' filter
// It allows altering a Widget properties right before output in sidebar
add_filter(\'widget_display_callback\', function($instance, $widget, $args){
    // This digs through arrays and objects all the way to non-iterative level
    array_walk_recursive($instance, function(&$value, $key){
        // Don\'t alter non-strings or empty ones
        if(!is_string($value) or empty($value)) return;
        // We found a string, replace stuff in it and return the altered value
        $value = str_replace(\'%REPLACEWHAT%\', \'%REPLACEWITH%\', $value);
    });
    // Return the possible altered $instance array
    return $instance;
}, 11, 3);