ValidationSummary Test Page.
Below are all overloads for Html.ValidationSummary. You should see 5 validation summary titles and 4 validation summary error messages.
@Html.ValidationSummary()
@Html.ValidationSummary(excludePropertyErrors: true)
@Html.ValidationSummary(message: "Hello from validation message summary 1.")
@Html.ValidationSummary(excludePropertyErrors: true, message: "Hello from validation message summary 2")
@Html.ValidationSummary(message: "Hello from validation message summary 3", htmlAttributes: new { style = "color: red" })
@Html.ValidationSummary(excludePropertyErrors: true, message: "Hello from validation message summary 4", htmlAttributes: new { style = "color: green" })
@Html.ValidationSummary(message: "Hello from validation message summary 5", htmlAttributes: new Dictionary { { "style", "color: blue" } })