{"id":1508,"date":"2015-02-26T10:41:29","date_gmt":"2015-02-26T09:41:29","guid":{"rendered":"http:\/\/www.matjazev.net\/blog\/?p=1508"},"modified":"2015-02-26T10:42:28","modified_gmt":"2015-02-26T09:42:28","slug":"xaml-datagrid-using-one-datatable-as-lookup","status":"publish","type":"post","link":"https:\/\/www.matjazev.net\/blog\/2015\/02\/26\/xaml-datagrid-using-one-datatable-as-lookup\/","title":{"rendered":"XAML DataGrid using one DataTable as lookup"},"content":{"rendered":"

Problem:<\/h2>\n

I have a DataTable with lookup column into another table<\/strong>. Another table is a small table so all the records can fit in small combobox<\/strong> and the user wants to be able to select lookup record with combobox.<\/p>\n

Solution:<\/h2>\n

XAML has DataGridComboBoxColumn, but it is difficult to bind<\/strong>, because DataGridComboBoxColumn can\u0092’t bind<\/strong> to Windows binding source. It is obviously quite know problem, but I could\u0092n’t find an easy solution.<\/p>\n

Test tables:<\/p>\n

\r\nMAIN_TABLE \r\n{ \r\n  ID, \r\n  SubTableID, \r\n  ... other fields ...\r\n}\r\n\r\nSUB_TABLE \r\n{ \r\n  ID, \r\n  Description \r\n}\r\n<\/pre>\n
Naive<\/h3>\n
Naive solution, that doesn’\u0092t work<\/p>\n
\r\n<DataGrid ItemsSource="{Binding mainTable}">\r\n  <DataGrid.Columns>\r\n    <DataGridTextColumn Header="ID" \r\n                        Binding="{Binding ID}" \/>\r\n    <DataGridTextColumn Header="SubID" \r\n                        Binding="{Binding SubTableID }" \/>\r\n    <DataGridComboBoxColumn Header="Desc" \r\n                            ItemsSource="{Binding subTable}}" <!-- can't bind! -->\r\n                            SelectedValueBinding="{Binding SubTableID}"\r\n                            SelectedValuePath="ID" \r\n                            DisplayMemberPath="Description" \/>\r\n  <\/DataGrid.Columns>            \r\n<\/DataGrid>\r\n<\/pre>\n
The solution doesn\u0092’t work because \u0096 for some reason\u0096 DataGridComboBoxColumn can’\u0092t bind subTable<\/strong> even if it is defined exactly as mainTable in datasource for the whole xaml window.<\/p>\n
Solution<\/h3>\n
The solution is quite easy. Create a resource that binds to sub table and then use that resurce sa data source \ud83d\ude42<\/p>\n
\r\n\r\n<DataGrid ItemsSource="{Binding mainTable}">\r\n  <DataGrid.Resources>\r\n    <CollectionViewSource x:Key="cvsSubTable" \r\n                          Source="{Binding subTable }"\/> <!-- can bind! -->\r\n  <\/DataGrid.Resources>\r\n  <DataGrid.Columns>\r\n    <DataGridTextColumn Header="ID" \r\n                        Binding="{Binding ID}" \/>\r\n    <DataGridTextColumn Header="SubID" \r\n                        Binding="{Binding SubTableID }" \/>\r\n    <DataGridComboBoxColumn Header="Desc" \r\n                            ItemsSource="{Binding Source={StaticResource cvsSubTable }}"  <!-- now it is ok! --> \r\n                            SelectedValueBinding="{Binding SubTableID}"\r\n                            SelectedValuePath="ID" \r\n                            DisplayMemberPath="Description" \/>\r\n  <\/DataGrid.Columns>            \r\n<\/DataGrid>         \r\n<\/pre>\n
Lost 4 hours on that! Grrrr..<\/p>\n","protected":false},"excerpt":{"rendered":"
Problem: I have a DataTable with lookup column into another table. Another table is a small table so all the records can fit in small combobox and the user wants to be able to select lookup record with combobox. Solution: XAML has DataGridComboBoxColumn, but it is difficult to bind, because DataGridComboBoxColumn can\u0092’t bind to Windows … Continue reading XAML DataGrid using one DataTable as lookup<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35,34],"tags":[60,59,58],"_links":{"self":[{"href":"https:\/\/www.matjazev.net\/blog\/wp-json\/wp\/v2\/posts\/1508"}],"collection":[{"href":"https:\/\/www.matjazev.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.matjazev.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.matjazev.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.matjazev.net\/blog\/wp-json\/wp\/v2\/comments?post=1508"}],"version-history":[{"count":20,"href":"https:\/\/www.matjazev.net\/blog\/wp-json\/wp\/v2\/posts\/1508\/revisions"}],"predecessor-version":[{"id":1528,"href":"https:\/\/www.matjazev.net\/blog\/wp-json\/wp\/v2\/posts\/1508\/revisions\/1528"}],"wp:attachment":[{"href":"https:\/\/www.matjazev.net\/blog\/wp-json\/wp\/v2\/media?parent=1508"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.matjazev.net\/blog\/wp-json\/wp\/v2\/categories?post=1508"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.matjazev.net\/blog\/wp-json\/wp\/v2\/tags?post=1508"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}