Use a dynamic value field to specify a constant (the default) or an expression. Click the expression icon fx to switch from constant to expression. Click the constant icon X to switch from expression to constant. An expression can include a variable to make the property value dynamic, or can simply be the name of a variable. You can apply a filter to a variable value using a pipe. The binding to the variable is a read. If you want to write to the variable, use a bidirectional bond. Examples: