{"id":80,"date":"2009-06-13T15:52:05","date_gmt":"2009-06-13T14:52:05","guid":{"rendered":"http:\/\/www.ms-mueller.ch\/wp\/?p=80"},"modified":"2009-06-13T15:52:05","modified_gmt":"2009-06-13T14:52:05","slug":"datagridview-properties-von-unterobjekten-anzeigen","status":"publish","type":"post","link":"https:\/\/www.ms-mueller.ch\/?p=80","title":{"rendered":"Datagridview – Properties von Unterobjekten anzeigen."},"content":{"rendered":"

Das Datagridview hat einen ganz entscheidenen Nachteil.<\/p>\n

Man kann keine Daten von Unterobjekten anzeigen.<\/p>\n

Es gibt einige L\u00f6sungsans\u00e4tze:<\/p>\n

http:\/\/www.developer-corner.com\/Resources\/KnowledgeBase\/tabid\/118\/articleType\/ArticleView\/articleId\/28\/Default.aspx<\/a><\/p>\n

http:\/\/blogs.msdn.com\/msdnts\/archive\/2007\/01\/19\/how-to-bind-a-datagridview-column-to-a-second-level-property-of-a-data-source.aspx<\/a><\/p>\n

Ich habe mich f\u00fcr die erste Variante entschieden sie aber leicht abge\u00e4ndert.<\/p>\n

Als erstet erstellen wir eine eigene DataGridViewKlasse und leiten von DataGridView ab.<\/p>\n

Public Class<\/span> MyDataGridView\n\u00a0\u00a0\u00a0 Inherits <\/span>Forms.DataGridView<\/pre>\n
End Class<\/span><\/pre>\n
Und dann \u00fcberschreiben wir das OnCellFormat Ereigniss:<\/p>\n
\nPublic Class<\/span> MyDataGridView\n\u00a0\u00a0\u00a0 Inherits <\/span>System.Windows.Forms.DataGridView\n\n    Protected Overrides Sub<\/span> OnCellFormatting( _ \n              ByVal <\/span>e As<\/span> System.Windows.Forms.DataGridViewCellFormattingEventArgs)\n\n        MyBase<\/span>.OnCellFormatting(e)\n        If<\/span> Me<\/span>.Rows(e.RowIndex).DataBoundItem IsNot Nothing _\n\u00a0          AndAlso<\/span> Me<\/span>.Columns(e.ColumnIndex).DataPropertyName.Contains(\".\"<\/span>) Then<\/span>\n            e.Value = BindProperty( _\n                 Me<\/span>.Rows(e.RowIndex).DataBoundItem, _\n                 Me<\/span>.Columns(e.ColumnIndex).DataPropertyName, 0)\n        End If<\/span>\n\n    End Sub<\/span>\nEnd Class<\/span><\/pre>\n
Und nun m\u00fcssen wir noch rekursiv das Richtige Objekt an die Zelle binden.<\/p>\n
\nPublic Class<\/span> MyDataGridView\n\u00a0\u00a0\u00a0 Inherits <\/span>System.Windows.Forms.DataGridView\n\n    Protected Overrides Sub<\/span> OnCellFormatting( _ \n              ByVal <\/span>e As<\/span> System.Windows.Forms.DataGridViewCellFormattingEventArgs)\n\n        MyBase<\/span>.OnCellFormatting(e)\n        If<\/span> Me<\/span>.Rows(e.RowIndex).DataBoundItem IsNot Nothing _\n          \u00a0AndAlso<\/span> Me<\/span>.Columns(e.ColumnIndex).DataPropertyName.Contains(\".\"<\/span>) Then<\/span>\n            e.Value = BindProperty( _\n                 Me<\/span>.Rows(e.RowIndex).DataBoundItem, _\n                 Me<\/span>.Columns(e.ColumnIndex).DataPropertyName, 0)\n        End If<\/span>\n\n    End Sub<\/span>\n\n    Private Function <\/span>BindProperty(ByVal <\/span>dataItem As Object<\/span>, _\n           \u00a0ByVal <\/span>bindingPath As String<\/span>, ByVal <\/span>index As Integer<\/span>) As Object<\/span>\n\n        Dim <\/span>tokens = bindingPath.Split(New Char() {CChar<\/span>(\".\"<\/span>)})\n        Dim <\/span>token = tokens(index)\n\n        Dim <\/span>t = dataItem.GetType()\n        Dim <\/span>pi = t.GetProperty(token)\n        Dim <\/span>nextDataItem As Object<\/span>\n\n        If <\/span>(pi IsNot <\/span>Nothing<\/span>) Then<\/span>\n\n            nextDataItem = pi.GetValue(dataItem, Nothing)\n\n            If <\/span>(index = tokens.Length - 1) Then<\/span>\n\n                Return <\/span>nextDataItem\n            End If<\/span>\n\n            Return <\/span>BindProperty(nextDataItem, bindingPath, index + 1)\n        End If<\/span>\n\n        Return Nothing<\/span>\n\n    End Function<\/span>\nEnd Class<\/span><\/pre>\n
So nun kann man im Designer dem Datagridview ungebundene Felder hinzuf\u00fcgen und dann bei DataProperty die Eigenschaft angeben:<\/p>\n
\nAdresse.Strasse<\/pre>\n
Und das MyDataGridView l\u00f6st das auf. Da wir das Feld an das Objekt gebunden haben lassen sich auf \u00e4nderungen am Wert durchf\u00fchren.<\/p>\n
Man muss beim speichern einfach beachten das die Unterobjekte dann mit gespeichert werden m\u00fcssen.<\/p>\n
Gruss Marco<\/p>\n","protected":false},"excerpt":{"rendered":"
Das Datagridview hat einen ganz entscheidenen Nachteil. Man kann keine Daten von Unterobjekten anzeigen. Es gibt einige L\u00f6sungsans\u00e4tze: http:\/\/www.developer-corner.com\/Resources\/KnowledgeBase\/tabid\/118\/articleType\/ArticleView\/articleId\/28\/Default.aspx http:\/\/blogs.msdn.com\/msdnts\/archive\/2007\/01\/19\/how-to-bind-a-datagridview-column-to-a-second-level-property-of-a-data-source.aspx Ich habe mich f\u00fcr die erste Variante entschieden sie aber leicht abge\u00e4ndert. Als erstet erstellen wir eine eigene DataGridViewKlasse und leiten von DataGridView ab. Public Class MyDataGridView \u00a0\u00a0\u00a0 Inherits Forms.DataGridView End Class Und dann \u00fcberschreiben […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[9,15,18],"class_list":["post-80","post","type-post","status-publish","format-standard","hentry","category-visual-studio","tag-controls","tag-vb","tag-vs"],"_links":{"self":[{"href":"https:\/\/www.ms-mueller.ch\/index.php?rest_route=\/wp\/v2\/posts\/80","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ms-mueller.ch\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ms-mueller.ch\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ms-mueller.ch\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ms-mueller.ch\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=80"}],"version-history":[{"count":0,"href":"https:\/\/www.ms-mueller.ch\/index.php?rest_route=\/wp\/v2\/posts\/80\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ms-mueller.ch\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=80"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ms-mueller.ch\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=80"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ms-mueller.ch\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=80"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}