C# Attribute.FirstOrDefault方法代码示例

        protected override ITransactionAttribute FindTransactionAttribute(Attribute[] attributes)
        {
            if (attributes == null)
            {
                return null;
            }

            var attribute = attributes.FirstOrDefault(attr => attr is TransactionAttribute) as TransactionAttribute;

            if(attribute == null)
            {
                return null;
            }

            var ruleBasedTransactionAttribute = new RuleBasedTransactionAttribute
                                                    {
                                                        PropagationBehavior = attribute.TransactionPropagation,
                                                        TransactionIsolationLevel = attribute.IsolationLevel,
                                                        ReadOnly = attribute.ReadOnly,
                                                        EnterpriseServicesInteropOption =
                                                            attribute.EnterpriseServicesInteropOption
                                                    };

            IEnumerable<Attribute> rollBackFor = attribute.RollbackFor.Select(type => new RollbackRuleAttribute(type) as Attribute);
            IEnumerable<Attribute> noRollBackFor = attribute.NoRollbackFor.Select(type => new NoRollbackRuleAttribute(type) as Attribute);
            IList<Attribute> rollBackRules = rollBackFor.Union(noRollBackFor).ToList();                   
            
            ruleBasedTransactionAttribute.RollbackRules = rollBackRules.ToList();

            return ruleBasedTransactionAttribute;
        }

        //For generic automatic editors. Passing a MemberInfo will also check for attributes
        public static object GenericField(string name, object value, Type t, MemberInfo member = null, object instance = null)
        {
            if (t == null){
                GUILayout.Label("NO TYPE PROVIDED!");
                return value;
            }

            //Preliminary Hides
            if (typeof(Delegate).IsAssignableFrom(t)){
                return value;
            }

            name = name.SplitCamelCase();

            //

            IEnumerable<Attribute> attributes = new Attribute[0];
            if (member != null){

                //Hide class?
                if (t.GetCustomAttributes(typeof(HideInInspector), true ).FirstOrDefault() != null){
                    return value;
                }

                attributes = member.GetCustomAttributes(true).Cast<Attribute>();

                //Hide field?
                if (attributes.Any(a => a is HideInInspector) ){
                    return value;
                }

                //Is required?
                if (attributes.Any(a => a is RequiredFieldAttribute)){
                    if ( (value == null || value.Equals(null) ) ||
                        (t == typeof(string) && string.IsNullOrEmpty((string)value) ) ||
                        (typeof(BBParameter).IsAssignableFrom(t) && (value as BBParameter).isNull) )
                    {
                        GUI.backgroundColor = lightRed;
                    }
                }
            }

            if (member != null){
                var nameAtt = attributes.FirstOrDefault(a => a is NameAttribute) as NameAttribute;
                if (nameAtt != null){
                    name = nameAtt.name;
                }

                if (instance != null){
                    var showAtt = attributes.FirstOrDefault(a => a is ShowIfAttribute) as ShowIfAttribute;
                    if (showAtt != null){
                        var targetField = instance.GetType().GetField(showAtt.fieldName);
                        if (targetField == null || targetField.FieldType != typeof(bool)){
                            GUILayout.Label(string.Format("[ShowIf] Error: bool \"{0}\" does not exist.", showAtt.fieldName));
                        } else {
                            if ((bool)targetField.GetValue(instance) != showAtt.show){
                                return value;
                            }
                        }
                    }
                }
            }

            //Before everything check BBParameter
            if (typeof(BBParameter).IsAssignableFrom(t)){
                return BBParameterField(name, (BBParameter)value, false, member);
            }

            //Cutstom object drawers
            var objectDrawer = GetCustomDrawer(t);
            if (objectDrawer != null && !(objectDrawer is NoDrawer) ){
                return objectDrawer.DrawGUI(name, value, member as FieldInfo, null, instance);
            }

            //Cutstom attribute drawers
            foreach(CustomDrawerAttribute att in attributes.OfType<CustomDrawerAttribute>()){
                var attributeDrawer = GetCustomDrawer(att.GetType());
                if (attributeDrawer != null && !(attributeDrawer is NoDrawer)){
                    return attributeDrawer.DrawGUI(name, value, member as FieldInfo, att, instance);
                }
            }

            //Then check UnityObjects
            if ( typeof(UnityObject).IsAssignableFrom(t) ) {
                if (t == typeof(Component) && (Component)value != null)
                    return ComponentField(name, (Component)value, typeof(Component));
                return EditorGUILayout.ObjectField(name, (UnityObject)value, t, true);
            }

            //Force UnityObject field?
            if (member != null && attributes.Any(a => a is ForceObjectFieldAttribute)){
                return EditorGUILayout.ObjectField(name, value as UnityObject, t, true );
            }

            //Restricted popup values?
            if (member != null){
                var popAtt = attributes.FirstOrDefault(a => a is PopupFieldAttribute) as PopupFieldAttribute;
                if (popAtt != null){
                    if (popAtt.staticPath != null){
//.........这里部分代码省略.........