How to set Filter Criteria with multi conditions in C#

To achieve your goal of setting multi-condition filters in DevExpress GridControl, you can build the required filter expression using various CriteriaOperator class descendants.

• GroupOperator: Combines multiple conditions using logical operators like AND or OR.
• BinaryOperator: Compares a column value to a constant (e.g., Column > 100).
• LikeOperator: Used for text pattern matching (e.g., Column LIKE '%ABC%').
• FunctionOperator: Applies functions to column values (e.g., Column1 > Function('NOW')).

var criterion = new GroupOperator() { OperatorType = GroupOperatorType.Or };  
criterion.Operands.Add(new FunctionOperator(FunctionOperatorType.StartsWith, new OperandProperty("Name"), new ConstantValue('r')));  
criterion.Operands.Add(new BinaryOperator("Age", 10) { OperatorType = BinaryOperatorType.Equal });  
criterion.Operands.Add(new BinaryOperator("Age", 5) { OperatorType = BinaryOperatorType.LessOrEqual });  
gridView.FilterCriteria = criterion;  

By combining these classes, you can create complex filter expressions and apply them to the GridView's ActiveFilterCriteria property to filter data based on multiple conditions.

As an alternative, you can create a string representation of the required filter expression and then parse it using the CriteriaOperator.Parse method. This method allows you to define the filter as a string (e.g., "Column1 > 100 AND Column2 LIKE '%ABC%'") and then convert it into a CriteriaOperator object, which can be applied to the ActiveFilterCriteria property of the GridView.

gridView.FilterCriteria = CriteriaOperator.Parse("StartsWith([Name], 'r') OR [Age]=10 OR [Age]<= 5");  

This approach simplifies the process of defining filters without manually constructing operator objects.