C# ModelStateDictionary.TryGetValue方法代码示例

        public static void AddModelStateErrors(this RulesException exception, ModelStateDictionary modelState, string prefix, Func<ErrorInfo, bool> errorFilter)
        {
            if (errorFilter == null) throw new ArgumentNullException("errorFilter");
            prefix = prefix == null ? "" : prefix + ".";
            foreach (var errorInfo in exception.Errors.Where(errorFilter))
            {
                var key = prefix + errorInfo.PropertyName;
                modelState.AddModelError(key, errorInfo.ErrorMessage);

                ModelState existingModelStateValue;
                if (modelState.TryGetValue(key, out existingModelStateValue) && existingModelStateValue.Value == null)
                    existingModelStateValue.Value = new ValueProviderResult(null, null, null);
            }
        }

        public void AddModelStateErrors(ModelStateDictionary modelState, string prefix, Func<ErrorInfo, bool> errorFilter)
        {
            if (errorFilter == null) throw new ArgumentNullException("errorFilter");
            prefix = prefix == null ? "" : prefix + ".";
            foreach (var errorInfo in Errors.Where(errorFilter)) {
                var key = prefix + errorInfo.PropertyName;
                modelState.AddModelError(key, errorInfo.ErrorMessage);

                // Workaround for http://xval.codeplex.com/WorkItem/View.aspx?WorkItemId=1297 (ASP.NET MVC bug)
                // Ensure that some value object is registered in ModelState under this key
                ModelState existingModelStateValue;
                if(modelState.TryGetValue(key, out existingModelStateValue) && existingModelStateValue.Value == null)
                    existingModelStateValue.Value = new ValueProviderResult(null, null, null);
            }
        }

        private GridResponse(ModelStateDictionary modelStateDictionary)
            : this()
        {
            Success = modelStateDictionary.IsValid;
            List<string> errors = new List<string>();
            foreach (string key in modelStateDictionary.Keys)
            {
                ModelState modelState;
                if (modelStateDictionary.TryGetValue(key, out modelState))
                {
                    if (modelState.Errors.Any())
                    {
                        string error = string.Format("<b>{0}</b>: ", key);
                        error += string.Join(", ", modelState.Errors.Select(err => err.ErrorMessage));
                        errors.Add(error);
                    }
                }
            }

            Message = string.Join("<br />", errors);
        }

        /// <summary>
        /// Check if we should validate property.
        /// If not, then clear out in ValueProvider.
        /// </summary>
        /// <param name="conditionPropertyName"></param>
        /// <param name="validateIfNot"></param>
        /// <param name="propertyName"></param>
        /// <param name="containerName"></param>
        /// <param name="instance"></param>
        /// <param name="property"></param>
        /// <param name="valueProvider"></param>
        /// <param name="modelState"></param>
        /// <returns>null if condition property is not in ValueProvider,
        ///          true if we should validate, false otherwise.</returns>
        private static bool? ShouldValidate(string conditionPropertyName, bool validateIfNot, string propertyName, string containerName, object instance, PropertyInfo property, IValueProvider valueProvider, ModelStateDictionary modelState)
        {
            var valueProviderResult = valueProvider.GetValue(conditionPropertyName);

            if (valueProviderResult == null)
            {
                // value for condition property is not supplied.
                return null;
            }

            bool shouldValidate = (bool)valueProviderResult.ConvertTo(_boolType);

            // invert ValidateIfNot will give us correct right condition for test.
            bool condition = !validateIfNot;

            if (shouldValidate == condition)
            {
                // let the normal validation handle it.
                return true;
            }
            else
            {
                // set property on model equalt to default(T) where T is property type.
                var v = property.PropertyType.IsValueType ? Activator.CreateInstance(property.PropertyType) : null;
                property.SetValue(instance, v, null);

                // also set ViewData.ModelState entry to default(T) where T is property type.
                // or else Html.TextBoxFor() etc. will pick up value from request and render it.
                ModelState ms;
                string key = containerName != "" ? containerName + "." + propertyName : propertyName;

                if (modelState.TryGetValue(key, out ms))
                {
                    if (ms.Value != null)
                    {
                        // these properties has proteced setters, so need a bit of reflection to
                        // clear out.
                        var msValueType = ms.Value.GetType();
                        var propertyDesc = msValueType.GetProperty("RawValue");
                        propertyDesc.SetValue(ms.Value, v, null);

                        propertyDesc = msValueType.GetProperty("AttemptedValue");
                        propertyDesc.SetValue(ms.Value, null, null);

                        // remove validation errors. needed for WrapNumericModelValidator.
                        ms.Errors.Clear();
                    }
                }

                return false;
            }
        }