Regola Larghezza colonna DBGrid

Question

Ho un TDBGrid. Funziona, ma le colonne mostrate sono molto grandi.

Come è possibile impostare una "larghezza della colonna di auto-correzione"?

Answer 1

La larghezza di colonna necessaria dipende dalle impostazioni dell'area di disegno delle griglie e dalla lunghezza minima del testo visualizzato di ciascun campo.

procedure FitGrid(Grid: TDBGrid); 
const 
    C_Add=3; 
var 
    ds: TDataSet; 
    bm: TBookmark; 
    i: Integer; 
    w: Integer; 
    a: Array of Integer; 
begin 
    ds := Grid.DataSource.DataSet; 
    if Assigned(ds) then 
    begin 
    ds.DisableControls; 
    bm := ds.GetBookmark; 
    try 
     ds.First; 
     SetLength(a, Grid.Columns.Count); 
     while not ds.Eof do 
     begin 
     for I := 0 to Grid.Columns.Count - 1 do 
     begin 
      if Assigned(Grid.Columns[i].Field) then 
      begin 
      w := Grid.Canvas.TextWidth(ds.FieldByName(Grid.Columns[i].Field.FieldName).DisplayText); 
      if a[i] < w then 
       a[i] := w ; 
      end; 
     end; 
     ds.Next; 
     end; 
     for I := 0 to Grid.Columns.Count - 1 do 
     Grid.Columns[i].Width := a[i] + C_Add; 
     ds.GotoBookmark(bm); 
    finally 
     ds.FreeBookmark(bm); 
     ds.EnableControls; 
    end; 
    end; 
end; 

procedure TForm1.Button1Click(Sender: TObject); 
begin 
    FitGrid(DBgrid1) 
end; 

Answer 2

piccola modifica della risposta di bummi per assicurare che il titolo riga (riga 0) non è troncato

procedure FitGrid(Grid: TDBGrid); 
const 
    C_Add=3; 
var 
    ds: TDataSet; 
    bm: TBookmark; 
    i: Integer; 
    w: Integer; 
    a: Array of Integer; 
begin 
    ds := Grid.DataSource.DataSet; 
    if Assigned(ds) then 
    begin 
    ds.DisableControls; 
    bm := ds.GetBookmark; 
    try 
     ds.First; 
     SetLength(a, Grid.Columns.Count); 
     while not ds.Eof do 
     begin 
     for I := 0 to Grid.Columns.Count - 1 do 
     begin 
      if Assigned(Grid.Columns[i].Field) then 
      begin 
      w := Grid.Canvas.TextWidth(ds.FieldByName(Grid.Columns[i].Field.FieldName.).DisplayText); 
      if a[i] < w then 
       a[i] := w ; 
      end; 
     end; 
     ds.Next; 
     end; 
     //if fieldwidth is smaller than Row 0 (field names) fix 
     for I := 0 to Grid.Columns.Count - 1 do 
     begin 
     w := Grid.Canvas.TextWidth(Grid.Columns[i].Field.FieldName); 
     if a[i] < w then 
      a[i] := w ; 
     end; 

     for I := 0 to Grid.Columns.Count - 1 do 
     Grid.Columns[i].Width := a[i] + C_Add; 
     ds.GotoBookmark(bm); 
    finally 
     ds.FreeBookmark(bm); 
     ds.EnableControls; 
    end; 
    end; 
end; 

Answer 3

piccola modifica della risposta di bummi per assicurare che il titolo riga (riga 0), non viene troncato, e spazio in eccesso sarà assegnato su ogni colonna

procedure FitGrid(Grid: TDBGrid); 
const 
    C_Add = 3; 
var 
    ds: TDataSet; 
    bm: TBookmark; 
    i: Integer; 
    w: Integer; 
    a: array of Integer; 
begin 
    ds := Grid.DataSource.DataSet; 

    if not Assigned(ds) then 
    exit; 

    if Grid.Columns.Count = 0 then 
    exit; 

    ds.DisableControls; 
    bm := ds.GetBookmark; 
    try 
    ds.First; 
    SetLength(a, Grid.Columns.Count); 
    for i := 0 to Grid.Columns.Count - 1 do 
     if Assigned(Grid.Columns[i].Field) then 
     a[i] := Grid.Canvas.TextWidth(Grid.Columns[i].FieldName); 

    while not ds.Eof do 
    begin 

     for i := 0 to Grid.Columns.Count - 1 do 
     begin 
     if not Assigned(Grid.Columns[i].Field) then 
      continue; 

     w := Grid.Canvas.TextWidth(ds.FieldByName(Grid.Columns[i].Field.FieldName).DisplayText); 

     if a[i] < w then 
      a[i] := w; 
     end; 
     ds.Next; 
    end; 

    w := 0; 
    for i := 0 to Grid.Columns.Count - 1 do 
    begin 
     Grid.Columns[i].Width := a[i] + C_Add; 
     inc(w, a[i] + C_Add); 
    end; 

    w := (Grid.ClientWidth - w - 20) div (Grid.Columns.Count); 

    if w > 0 then 
     for i := 0 to Grid.Columns.Count - 1 do 
     Grid.Columns[i].Width := Grid.Columns[i].Width + w; 


    ds.GotoBookmark(bm); 
    finally 
    ds.FreeBookmark(bm); 
    ds.EnableControls; 
    end; 
end; 

Answer 4

modifica minore di bummi di, TheSteven di risposte e Jens' per assicurare che il titolo riga (riga 0), non viene troncato, e spazio in eccesso sarà allo in ogni colonna, e rendere visibile le colonne nell'account.

procedure FitGrid(const Grid: TDBGrid; const CoverWhiteSpace: Boolean = True); 
const 
    C_Add=3; 
var 
    DS: TDataSet; 
    BM: TBookmark; 
    I, W, VisibleColumnsCount: Integer; 
    A: array of Integer; 
    VisibleColumns: array of TColumn; 
begin 
    DS := Grid.DataSource.DataSet; 
    if Assigned(DS) then 
    begin 
    VisibleColumnsCount := 0; 
    SetLength(VisibleColumns, Grid.Columns.Count); 
    for I := 0 to Grid.Columns.Count - 1 do 
     if Assigned(Grid.Columns[I].Field) and (Grid.Columns[I].Visible) then 
     begin 
     VisibleColumns[VisibleColumnsCount] := Grid.Columns[I]; 
     Inc(VisibleColumnsCount); 
     end; 
    SetLength(VisibleColumns, VisibleColumnsCount); 

    DS.DisableControls; 
    BM := DS.GetBookmark; 
    try 
     DS.First; 
     SetLength(A, VisibleColumnsCount); 
     while not DS.Eof do 
     begin 
     for I := 0 to VisibleColumnsCount - 1 do 
     begin 
      W := Grid.Canvas.TextWidth(DS.FieldByName(VisibleColumns[I].Field.FieldName).DisplayText); 
      if A[I] < W then 
       A[I] := W; 
     end; 
     DS.Next; 
     end; 
     //if fieldwidth is smaller than Row 0 (field names) fix 
     for I := 0 to VisibleColumnsCount - 1 do 
     begin 
     W := Grid.Canvas.TextWidth(VisibleColumns[I].Field.FieldName); 
     if A[I] < W then 
      A[I] := W; 
     end; 

     W := 0; 
     if CoverWhiteSpace then 
     begin 
     for I := 0 to VisibleColumnsCount - 1 do 
      Inc(W, A[I] + C_Add); 
     W := (Grid.ClientWidth - W - 20) div VisibleColumnsCount; 
     if W < 0 then 
      W := 0; 
     end; 

     for I := 0 to VisibleColumnsCount - 1 do 
     VisibleColumns[I].Width := A[I] + C_Add + W; 
     DS.GotoBookmark(BM); 
    finally 
     DS.FreeBookmark(BM); 
     DS.EnableControls; 
    end; 
    end; 
end;