Please implement the IDataErrorInfo interface on the data object. Then, pass the text and type of error in the IDataErrorInfo.Error property ( it is possible to easily parse this string). Implement a custom style for the ErrorControl. This element presents the error icon. Modify the ErrorControl style in such a way as to take into account a custom error type and text (use the converter).
-
](https://www.devexpress.com/support/examples/survey.xml?utm_source=github&utm_campaign=wpf-editors-validate-user-input-indicate-errors-idataerrorinfo&~~~was_helpful=yes) [
](https://www.devexpress.com/support/examples/survey.xml?utm_source=github&utm_campaign=wpf-editors-validate-user-input-indicate-errors-idataerrorinfo&~~~was_helpful=no)
-
+## Does this example address your development requirements/objectives?
+
+[](https://www.devexpress.com/support/examples/survey.xml?utm_source=github&utm_campaign=wpf-editors-validate-user-input-indicate-errors-idataerrorinfo&~~~was_helpful=yes) [](https://www.devexpress.com/support/examples/survey.xml?utm_source=github&utm_campaign=wpf-editors-validate-user-input-indicate-errors-idataerrorinfo&~~~was_helpful=no)
+
(you will be redirected to DevExpress.com to submit your response)
From 944f13c07331221140e41bd590d4a95664848eef Mon Sep 17 00:00:00 2001
From: Serge Pilipchuk <112853396+sergepilipchuk@users.noreply.github.com>
Date: Thu, 18 Sep 2025 16:29:07 +0400
Subject: [PATCH 3/6] Update readme (Implementation details)
---
Readme.md | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 65 insertions(+), 2 deletions(-)
diff --git a/Readme.md b/Readme.md
index 9b5e47b..046ec93 100644
--- a/Readme.md
+++ b/Readme.md
@@ -7,11 +7,74 @@
# WPF Editors - Indicate Errors and Warnings by Implementing IDataErrorInfo
-Please implement the `IDataErrorInfo` interface on the data object. Then, pass the text and type of error in the `IDataErrorInfo.Error` property ( it is possible to easily parse this string). Implement a custom style for the `ErrorControl`. This element presents the error icon. Modify the `ErrorControl` style in such a way as to take into account a custom error type and text (use the converter).
+This example validates the input field and displays error indicators in DevExpress editors. The solution implements the standard `IDataErrorInfo` interface and uses a custom `ErrorControl` style to display different icons and messages for errors, warnings, and informational notes.
+
+Users can see visual indicators (error, warning, information) directly in the editor. Each indicator includes a descriptive message that helps users quickly fix input mistakes.
+
+GIF
## Implementation Details
-...
+### Create Validation Logic
+
+The data object implements the `IDataErrorInfo` interface. The `Error` property returns a formatted string that includes the error type and message:
+
+```csharp
+public class TestClass : IDataErrorInfo {
+ public string TestString { get; set; }
+
+ string IDataErrorInfo.Error {
+ get { return GetError(); }
+ }
+
+ string GetError() {
+ if (string.IsNullOrEmpty(TestString))
+ return "ErrorType=Critical;ErrorContent=The value is not provided. Please enter a value";
+ if (TestString.Length < 3)
+ return "ErrorType=Warning;ErrorContent=The value is less than 3 characters. Please enter at least 5 characters";
+ if (TestString.Length < 5)
+ return "ErrorType=Information;ErrorContent=The value is less than 5 characters. Please enter at least 5 characters";
+ return string.Empty;
+ }
+
+ string IDataErrorInfo.this[string columnName] {
+ get {
+ if (columnName == "TestString")
+ return GetError();
+ return string.Empty;
+ }
+ }
+}
+```
+
+### Parse Error Content
+
+The error string encodes multiple values (`ErrorType` and `ErrorContent`). A value converter extracts the required part of the string that displays it in the UI:
+
+```csharp
+public class ErrorContentConverter : IValueConverter {
+ public string GetValueTag { get; set; }
+ public string Separator { get; set; }
+
+ public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) {
+ if (value == null || !(value is string))
+ return value;
+ string error = System.Convert.ToString(value, culture);
+ if (string.IsNullOrEmpty(error))
+ return value;
+
+ string searchString = GetValueTag + "=";
+ foreach (string suberror in error.Split(new string[] { Separator }, StringSplitOptions.RemoveEmptyEntries)) {
+ if (suberror.Contains(searchString))
+ return suberror.Replace(searchString, string.Empty);
+ }
+ return value;
+ }
+ public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) {
+ return null;
+ }
+}
+```
## Files to Review
From 877f16e48921a2b14fbebcd2119731018a268022 Mon Sep 17 00:00:00 2001
From: Serge Pilipchuk <112853396+sergepilipchuk@users.noreply.github.com>
Date: Fri, 19 Sep 2025 10:19:22 +0400
Subject: [PATCH 4/6] Update readme file (minor changes)
---
Images/validation.jpg | Bin 0 -> 23005 bytes
Readme.md | 42 +++++++++++++++++++++++++++++++++++++++++-
2 files changed, 41 insertions(+), 1 deletion(-)
create mode 100644 Images/validation.jpg
diff --git a/Images/validation.jpg b/Images/validation.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9a38ef7c99aa0d11351f1a124fb1de3bdc04e9fa
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