Using Livebindings to Assign Several Field Values to an FMX MetropolisUI TListBox Item.Text

问题

I am coding a FMX Metropolis UI application and trying to assign two field values of type string to the Item.Title member of TListBox by LiveBindings technology (using expression engine).

When I use a TBindList in the following way:

object BindList1: TBindList
  Category = 'Lists'
  ControlComponent = ListBox1
  SourceComponent = BindSourceDB1
  FormatExpressions = <
    item
      ControlExpression = 'Text'
      SourceExpression =
        'FieldByName("name1").Text + " " + Field' +
        'ByName("name2").Text'
    end>
  FormatControlExpressions = <>
  ClearControlExpressions = <>
end

It assigns the 'name1 name2' string to the member Text but I fail to set the ListItemStyle := MetropolisUI as there is no such property in TBindList class

If I use TLinkFillControlToField

object LinkFillControlToField2: TLinkFillControlToField
      Category = 'Quick Bindings'
      Control = ListBox1
      Track = True
      FillDataSource = BindSourceDB1
      FillDisplayFieldName = 'name1'
      AutoFill = True
      BufferCount = -1
      AutoBufferCount = False
      FillExpressions = <>
      FillHeaderExpressions = <>
      FillBreakGroups = <>
    end

it lets me to assign ListItemStyle to MetropolisUI, but there is only one field that I can access with FillDisplayFieldName property and there is no SourceExpression field to assign 'FieldByName("name1").Text + " " + FieldByName("name2").Text' to it.

I tried to guess context of Item.Text member of TListBox from TBindList but I did not manage to. I studied Delphi samples but there is no Metropolis TListBox and it seems to act in a different way than the common one. Does anybody have any ideas how to find the solution for this issue?

回答1:

Thanks to the post of @house-of-dexter He gave an answer concerning TLabel that encouraged me to try TLinkFillControlToField once again. The main issue is that the context of the fieldname can be found in Self.Owner.

object LinkFillControlToField2: TLinkFillControlToField
  Category = 'Quick Bindings'
  DataSource = BindSourceDB1
  Control = ListBox1
  Track = True
  FillDataSource = BindSourceDB1
  AutoFill = True
  BufferCount = -1
  AutoBufferCount = False
  ListItemStyle = 'MetropolisUI'
  FillExpressions = <
    item
      SourceMemberName = 'name1'
      ControlMemberName = 'Title'
      CustomFormat = 'Self.Owner.name1.text+" "+Self.Owner.name2.text'
    end>
  FillHeaderExpressions = <>
  FillBreakGroups = <>
end

来源：https://stackoverflow.com/questions/31202376/using-livebindings-to-assign-several-field-values-to-an-fmx-metropolisui-tlistbo

标签

Delphi

microsoft-metro

firemonkey

livebindings

tlistbox