确定DataGrid默认视觉验证是否有错误

I am a newbie in WPF, I have always done validation for various UI controls using custom ValidationRule classes, however, when using DataGrid for the first time and binding it with a simple DataTable, I found that the DataGrid has a pretty good default validation that detects the type of DataTable columns and gives a visual error if a cell value is not of the same expected type. This is pretty enough for me that I thought no need to create custom validation rules as the default one is fitting my purpose. However, I have a Submit button that I need to disable if this DataGrid has any errors, so I thought that this would be easy utilizing the Validation.HasError property using the following code:I am a newbie in WPF, I have always done valida