delphi - TListView 组件中的复选框不滚动

Question

我创建了 ListView 并添加了复选框来检查每一行(如果需要)。一切都很好，直到 ListView 中有很多项目，因此需要对其进行排序。我在线检查，然后发现如果滚动滚动条，复选框不会与其他内容一起滚动。

我的代码:

unit ShareCommissionDialog;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, sButton, ComCtrls, sListView, sCheckBox, DataManager;

type
  TdlgShareCommission = class(TForm)
    lvEmployees: TsListView;
    btnCancel: TsButton;
    btnDone: TsButton;
    procedure FormCreate(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure btnDoneClick(Sender: TObject);
    procedure btnCancelClick(Sender: TObject);

  private
    manager: TDataManager;
    ListViewCheckBoxList: TList;
    employeeIDs: TStringList;

    procedure ListViewCheckBoxCreate(List: TsListView; employeeID: string; R: TRect);
    procedure ListViewCheckBoxClick(Sender: TObject);
    procedure ListViewCheckBoxSelected(item: Integer; List: TsListView);
    procedure ListViewCheckBoxUnselected(item: Integer; List: TsListView);

    procedure PopulateEmployees;
    procedure ShowSelectedEmployees;
    procedure MarkRows;

  public
    property DataManager: TDataManager read manager write manager;
    property CommissionReceivers: TStringList read employeeIDs write employeeIDs;

  end;

var
  dlgShareCommission: TdlgShareCommission;

implementation

{$R *.dfm}

procedure TdlgShareCommission.btnCancelClick(Sender: TObject);
begin
  employeeIDs := employeeIDs;
end;

procedure TdlgShareCommission.btnDoneClick(Sender: TObject);
var
  i, j: Integer;

begin
  employeeIDs := TStringList.Create;

  for i := 0 to ListViewCheckBoxList.Count - 1 do
  begin
    if TsCheckBox(ListViewCheckBoxList[i]).Checked then
    begin
      for j := 0 to manager.Data.Employees.Count - 1 do
      begin
        if TsCheckBox(ListViewCheckBoxList[i]).Tag = StrToInt(manager.Data.Employees[j].ID) then
        begin
          employeeIDs.Add(manager.Data.Employees[j].ID);
          Break;
        end;
      end;
    end;
  end;
end;

procedure TdlgShareCommission.FormClose(Sender: TObject;
  var Action: TCloseAction);
begin
  manager.GetEmployees(manager.Data.SelectedPOS.ID);
end;

procedure TdlgShareCommission.FormCreate(Sender: TObject);
begin
  ListViewCheckBoxList := TList.Create;
end;

procedure TdlgShareCommission.ListViewCheckBoxCreate(List: TsListView; employeeID: string; R: TRect);
function NewViewCheckBox: TsCheckBox;
  begin
    Result := TsCheckBox.Create(Self);
    Result.Tag := StrToInt(employeeID);
    Result.Parent := List;
    Result.BoundsRect := R;
    Result.Checked := False;

    Result.OnClick := ListViewCheckBoxClick;
  end;
begin
  ListViewCheckBoxList.Add(NewViewCheckBox);
end;

procedure TdlgShareCommission.FormShow(Sender: TObject);
begin
  if employeeIDs <> nil then
  begin
    PopulateEmployees;
    ShowSelectedEmployees;
    MarkRows;
  end
  else
  begin
    PopulateEmployees;
    MarkRows;
  end;

  //PopulateEmployees;
  //MarkRows;
end;

procedure TdlgShareCommission.ListViewCheckBoxClick(Sender: TObject);
var
  i: Integer;

begin
  for i := 0 to ListViewCheckBoxList.Count - 1 do
  begin
    if (i+1) <= (ListViewCheckBoxList.Count - 1) then
      if not TsCheckBox(ListViewCheckBoxList[i+1]).Enabled then
      begin
        TsCheckBox(ListViewCheckBoxList[i+1]).Checked := TsCheckBox(ListViewCheckBoxList[i]).Checked;
      end;
  end;

  MarkRows;
end;

procedure TdlgShareCommission.MarkRows;
var
  j: Integer;

begin
  for j := 0 to lvEmployees.Items.Count - 1 do
  begin
    if not TsCheckBox(ListViewCheckBoxList[j]).Checked then
    begin
      ListViewCheckBoxSelected(j, lvEmployees);
    end
    else
    begin
      ListViewCheckBoxUnselected(j, lvEmployees);
    end;
  end;
end;

procedure TdlgShareCommission.ListViewCheckBoxSelected(item: Integer; List: TsListView);
begin
  with List do
  begin
    Items[item].Selected := False;
  end;
end;

procedure TdlgShareCommission.ListViewCheckBoxUnselected(item: Integer; List: TsListView);
begin
  with List do
  begin
    Items[item].Selected := False;
  end;
end;

procedure TdlgShareCommission.PopulateEmployees;
var
  i: Integer;
  R: TRect;
  employeeRow: TListItem;

begin
  with lvEmployees do
  try
    Items.BeginUpdate;
    Items.Clear;

    manager.GetEmployees(manager.Data.SelectedPOS.ID);

    for i := 0 to manager.Data.Employees.Count - 1 do
    begin
      employeeRow := Items.Add;

      R := Items[i].DisplayRect(drBounds);
      R.Left := 5;
      R.Top := R.Top + 1;
      ListViewCheckBoxCreate(lvEmployees, manager.Data.Employees[i].ID, R);
      Items[i].Data := TsCheckBox(ListViewCheckBoxList[i]);

      employeeRow.SubItems.Add(manager.Data.Employees[i].FirstName + ' ' + manager.Data.Employees[i].LastName);
    end;
  finally
    lvEmployees.Items.EndUpdate;
  end;
end;

procedure TdlgShareCommission.ShowSelectedEmployees;
var
  i, j: Integer;

begin
  for j := 0 to lvEmployees.Items.Count - 1 do
  begin
    for i := 0 to employeeIDs.Count - 1 do
    begin
      if TsCheckBox(ListViewCheckBoxList[j]).Tag = StrToInt(employeeIDs[i]) then
      begin
        TsCheckBox(ListViewCheckBoxList[j]).Checked := True;
      end;
    end;
  end;
end;
end.

我需要在代码中添加什么以使复选框也能与其他内容一起滚动？

Answer 1

标准 ListView 有一个名为 checkboxes 的属性，可以将其设置为 true。
如果您使用它，那么您就不必费力制作自己的复选框。
我从未遇到过复选框在此控件中无法正确显示的问题。

此属性在 ViewStyle:= vsList 或 ViewStyle:= vsReport 中效果最佳

或者，如果您想要某些项目上的复选框而不是其他项目上的复选框然后制作一个复选框的图片(1 个未选中，1 个选中)并将它们都添加到 ImageList 中。
如果某个项目需要复选框，请将其 ImageIndex 属性设置为未选中项目的 ImageIndex 属性。如果需要勾选，则将其ImageIndex属性设置为勾选的Image。
这适用于 ViewStyle:= vsReport 和 ViewStyle:= vsList。

您正在使用自定义 ListView(TsListView) 控件，请尝试使用标准 ListView 来代替，看看是否会出现奇怪的行为。