动态DBGrid单元格着色

时间:2012-07-18 20:52:54

标签: delphi

我正在使用来自Jedi组件组(TJvDBGrid)的Delphi XE-2和DBGrid。现在,我发现在知道值时很容易定义单元格颜色,例如:

OnGetCellParams event: 
if DBGrid.Field.AsInteger = 0
then Background := clYellow;

但在我的情况下,用户可以定义哪个值将具有哪种颜色,即存储在单独的表中。我的问题是,有没有办法通过查找单元格值是否为其分配颜色来着色单元格?

感谢您对此事的任何帮助或指导,谢谢。

1 个答案:

答案 0 :(得分:2)

最简单的方法可能是使用表单OnCreate填充数组,然后在OnGetCellParams事件中访问该数组。数组应包含与可能值一样多的项目,如果尚未指定颜色,则应包含数组索引0的默认值。 (未经测试的袖口代码如下!)

type
  TForm1 = class(TForm)
    ...
    procedure FormCreate(Sender: TObject);
  private
    FColors: array of TColor;
  end;

implementation

procedure TForm1.FormCreate(Sender: TObject);
var
  NumRows, i: Integer;
begin
  // One row for each possible value for the integer column you're
  // trying to color the cell for (eg., if the table can hold a value
  // from 0-10, you need the same # of items in the array (array[0..10])
  NumRows := NumberOfPossibleValues;
  SetLength(FColors, NumberOfPossibleValues);

  // Pre-fill the array with the default clWindow color,
  // in case a custom color isn't assigned to a value
  // (for instance, the user doesn't set a color for a value
  // of 7).
  for i := 0 to High(FColors) do
    FColors[i] := clWindow;  

  // Assumes your color values are in a database called FieldColors,
  // in a datamodule called dmAppData, and that there's a
  // column named ColValue indicating the `Field.AsInteger`
  // value and the corresponding TColor stored as an integer.
  dmAppData.FieldColors.First;
  while not dmAppData.FieldColors.Eof do
  begin
    i := dmAppData.FieldColors.FieldByName('ColValue').AsInteger;

    // Might want to put a check here to make sure the value isn't
    // more than the number of items in the array!!!
    FColors[i] := TColor(dmAppData.FieldColors.FieldByName('Color').AsInteger);
    dmAppData.FieldColors.Next;
  end;
end;

OnGetCellParams事件中:

Background := FColors[DBGrid.Field.AsInteger];

您可能希望在OnGetCellParams中使用局部变量以确保保持在数组范围内:

Background := clWindow;
i := DBGrid.Field.AsInteger;
if (i > 0) and (i < Length(FColors)) then
  Background := FColors[i];

更慢的方法是在Locate事件中为每一行执行OnGetCellParams

OnGetCellParams

Background := clWindow;
if dmAppData.FieldColors.Locate('ColValue', DBGrid.Field.AsInteger, []) then
  Background := TColor(dmAppData.FieldColors.FieldByName('Color').AsInteger);