我对delphi开发非常陌生，我有一个自定义的CheckTreeList组件，该组件继承自cxTreeList Devexpress组件。当我检查列表中的某些节点时，这些值以如下所示的格式存储到字符串中String Format for selected nodes as image问题是我无法通过遍历字符串中的节点和值来检查清单树的节点。我尝试了下面的代码来保存和加载选中和未选中的节点。将已检查的节点键值保存为字符串是可行的，但是无法加载节点并对其进行检查。以下是组件源代码
unit DXCheckTreelist;
interface
uses
System.Classes, cxTL, cxLookAndFeelPainters;
type
TdxUnboundTreeListNode = class(TcxUnboundTreeListNode)
protected
procedure SetCheckState(AValue: TcxCheckBoxState); override;
end;
TdxCheckTreeList = class(TcxTreeList)
Private
FEnableStdTreebehaviour : Boolean;
protected
function CreateNode: TcxTreeListNode; override;
Published
Property EnableStdTreebehaviour: Boolean read FEnableStdTreebehaviour write FEnableStdTreebehaviour default False;
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('DX Components', [TdxCheckTreeList]);
end;
{ TdxCheckTreeList }
function TdxCheckTreeList.CreateNode: TcxTreeListNode;
begin
Result := TdxUnboundTreeListNode.Create(Self);
Changes := Changes + [tcStructure];
end;
{ TdxUnboundTreeListNode }
procedure TdxUnboundTreeListNode.SetCheckState(AValue: TcxCheckBoxState);
var
ParentNode : TdxUnboundTreeListNode;
PrevCheckState: TcxCheckBoxState;
const
AState: array[TcxCheckBoxState] of TcxTreeListNodeCheckInfos = ([], [nciChecked], [nciGrayed]);
AParentCheckState: array[Boolean] of TcxCheckBoxState = (cbsGrayed, cbsChecked);
begin
if TdxCheckTreeList(TreeList).FEnableStdTreebehaviour then
begin
inherited;
Exit;
end;
if not CanChecked then
begin
State := State - [nsCheckStateInvalid];
Exit;
end;
PrevCheckState := CheckState;
CheckInfo := CheckInfo - [nciChecked, nciGrayed] + AState[AValue] + [nciChangeCheck];
try
if (CheckState in [cbsChecked, cbsUnchecked]) and HasChildren then
begin
LoadChildren;
if AValue = cbsUnchecked then
SetChildrenCheckState(CheckState, nil);
end;
ParentNode := TdxUnboundTreeListNode(Parent);
if ParentNode <> nil then
begin
if ParentNode.IsRadioGroup and Checked then
ParentNode.SetChildrenCheckState(cbsUnchecked, Self);
if not (nciChangeCheck in ParentNode.CheckInfo) and (ParentNode <> Root) then
ParentNode.CheckState := cbsChecked;
end;
finally
CheckInfo := CheckInfo - [nciChangeCheck];
State := State - [nsCheckStateInvalid];
if CanChecked then
Repaint(True);
if (PrevCheckState <> CheckState) and Assigned(TcxTreeList(TreeList).OnNodeCheckChanged) then
TcxTreeList(TreeList).OnNodeCheckChanged(TreeList, Self, CheckState);
end;
end;
end.
在我的情况下，属性EnableStdTreebehaviour设置为true。
用于保存所选节点键值的代码为
procedure TfrmTreeList.btnSaveDataClick(Sender: TObject);
var
I, J: Integer;
node, cnode: TcxTreeListNode;
Result: String;
begin
result:= '';
for i := 0 to ctvMandatory.Count - 1 do
begin
node := TcxTreeListNode(ctvMandatory.Items[i]);
if ctvMandatory.Items[i].CheckState in [cbsChecked, cbsGrayed] then
begin
if node.Level = 0 then Result:= Result + '[' + node.Values[1] + ']' + ',';
for J := 0 to ctvMandatory.Items[i].Count - 1 do
begin
cnode := ctvMandatory.Items[i].Items[J];
if (cnode.Checked) and (cnode.Level = 1) then
begin
Result:= Result + cnode.Values[2] + ',';
end;
end;
end;
end;
if (Result <> '') and (Result[Length(result)] = ',') then
result:= Copy(Result, 1, length(Result) -1 );
Memo.Clear;
if result <> '' then
begin
Memo.Lines.Add(Trim(Result));
csv := result;
end;
for i := 0 to ctvMandatory.count - 1 do
begin
node := TcxTreeListNode(ctvMandatory.Items[i]);
ctvMandatory.Items[i].Checked := False;
end;
end;
我尝试加载并检查节点的代码取决于字符串的键值是
procedure TfrmTreeList.btnLoadDataClick(Sender: TObject);
var
i, j, X: integer;
node, cnode: TcxTreeListNode;
sl,s2: TStringList;
str: string;
key, value, val: string;
begin
chbAll.Checked:= csv = 'All';
ctvMandatory.BeginUpdate;
if chbAll.Checked then
begin
for i:= 0 to ctvMandatory.AbsoluteCount - 1 do
ctvMandatory.Items[I].Checked := True;
ctvMandatory.EndUpdate;
SetMandatoryText;
Exit;
end;
for i:= 0 to ctvMandatory.Count - 1 do
ctvMandatory.Items[I].Checked := False;
if csv = 'All' then
begin
for i:= 0 to ctvMandatory.AbsoluteCount - 1 do
ctvMandatory.Items[I].Checked := True;
end
else
if (length(csv) > 0) and (Pos(']', csv) = 0) then
begin
for i := 0 to ctvMandatory.Count - 1 do
begin
node:= TcxTreeListNode(ctvMandatory.Items[i]);
if node.Level = 0 then
ctvMandatory.Items[i].Checked:= True
else
if (node.Level = 1) and IsValueInCSV(csv, node.Values[1]) then
begin
ctvMandatory.Items[i].Checked := True;
end;
end;
end
else
begin
sl:= TStringList.Create;
sl.Delimiter:= ',';
sl.DelimitedText:= csv;
node:= nil;
s2:= TStringList.Create;
s2.Delimiter:= ',';
for str in sl do
begin
if (pos('[', str) > 0) then
begin
if (value <> '') and (value[Length(value)] = ',') then
value := Copy(value, 1, length(value) -1);
s2.DelimitedText:= value;
if (node <> nil) and (value <> '') and (node.HasChildren) then
begin
for I := 0 to ctvMandatory.Count - 1 do
begin
while Node <> Nil do
begin
node:= TcxTreeListNode(ctvMandatory.Items[I]);
node:= node.getFirstChild;
if not node.Checked then
begin
val := '';
for val in s2 do
begin
node.Checked := true;
node.getNextSibling;
end;
end;
s2.Clear;
end;
end;
end;
value:= '';
val := '';
key:= ReplaceStr(str, '[', '');
key:= ReplaceStr(key, ']', '');
for I := 0 to ctvMandatory.Count - 1 do
begin
if (TcxTreeListNode(ctvMandatory.Items[i]).Values[1] = key) and ((ctvMandatory.Items[i]).Level = 0) then
begin
node:= TcxTreeListNode(ctvMandatory.Items[i]);
Break;
end;
end;
end
else
begin
value:= value + str + ',';
end;
end;
if (value <> '') and (value[Length(value)] = ',') then
value := Copy(value, 1, length(value) -1);
s2.DelimitedText:= value;
if (node <> nil) and (value <> '') and (node.HasChildren) then
begin
for I := 0 to ctvMandatory.Count - 1 do
begin
while Node <> Nil do
begin
node:= TcxTreeListNode(ctvMandatory.Items[I]);
node:= node.getFirstChild;
if not node.Checked then
begin
val := '';
for val in s2 do
begin
node.Checked := true;
node.getNextSibling;
end;
end;
s2.Clear;
end;
end;
end;
sl.Free;
s2.Free;
end;
ctvMandatory.EndUpdate;
SetMandatoryText;
end;
function TfrmTreeList.IsValueInCSV(const CSV, Value: string): Boolean;
begin
Result := IsValueInCSV(CSV, Value, False);
end;
function TfrmTreeList.IsValueInCSV(const CSV, Value: string; ResultIfBothEmpty: Boolean): Boolean;
begin
if Trim(CSV) = Trim(Value) then
begin
if Trim(Value) = '' then
Result := ResultIfBothEmpty
else
Result := True;
end
else
Result := MatchStr(Value, SplitString(CSV, ','));
end;
有人可以在这个问题上检查并帮助我吗？
Update我已经更新了此答案，以提供一个完整且自包含的示例，该示例将TcxTreeList的复选标记保存到字符串（或TStringList），然后重新加载它们，两者都使用Q的屏幕截图。我已经忽略了Q中的代码，并从头开始编写了所有代码，因为这比尝试猜测您打算在代码中确切执行的操作要容易得多-如果我自己这样做，则不会使用Q的方法而是将树节点的状态保存到TClientDataSet或等效的Devex。
该示例仅需要几个实用程序例程即可完成工作，并且所有这些例程都将TcxTreeList或TcxTreeListNode作为输入参数，因此可以将它们移动到另一个单元并以其他形式重新使用。
这些例程如下：
function RootNodeToString(RootNode : TcxTreeListNode) : String;
// This saves a Root node and its subkeys in the format show in the Q's screenshot
// Note: This does NOT save the RootNode's checked state because the q did not define
// whether it should
function TreeListNodesToString(TreeList : TcxTreeList) : String;
// This saves all the TreeList's Root nodes and their subkeys
// in the format show in the Q's screenshot
function RootNodeFromName(TreeList : TcxTreeList; AName : String) : TcxTreeListNode;
// Finds the RootNode having a given name or NIL if not found
function ChildNodeFromName(RootNode : TcxTreeListNode; const AName : String) : TcxTreeListNode;
// Finds the ChildNode (of a RootNode) having a given name or NIL if not found
function TreeListNodesToString(TreeList : TcxTreeList) : String;
// This saves all the TreeList's Root nodes and their subkeys
// in the format show in the Q's screenshot
function RootNodeFromName(TreeList : TcxTreeList; AName : String) : TcxTreeListNode;
// Finds the RootNode having a given name or NIL if not found
function ChildNodeFromName(RootNode : TcxTreeListNode; const AName : String) : TcxTreeListNode;
// Finds the ChildNode (of a RootNode) having a given name or NIL if not found
procedure ClearChecks(TreeList : TcxTreeList; ClearChildren : Boolean);
// Clears all the checkmark in a cxTreeList
希望这些都是不言而喻的。示例的实现部分是
const
iCheckCol = 0; // the number of the checkbox column
iNameCol = 1; // the number of the name column
function RootNodeToString(RootNode : TcxTreeListNode) : String;
// This saves a Root node and its subkeys in the format show in the Q's screenshot
// Note: This does NOT save the RootNode's checked state because the q did not define
// whether it should
var
j : Integer;
ANode : TcxTreeListNode;
begin
Result := '[' + RootNode.Values[iNameCol] + ']';
for j := 0 to RootNode.Count - 1 do begin
ANode := RootNode.Items[j];
if ANode.Values[iCheckCol] then
Result := Result + ',' + ANode.Values[iNameCol];
end;
end;
function TreeListNodesToString(TreeList : TcxTreeList) : String;
// This saves all the TreeList's Root nodes and their subkeys
// in the format show in the Q's screenshot
var
i : Integer;
begin
Result := '';
for i := 0 to TreeList.Count - 1 do begin
if Result <> '' then
Result := Result + ',';
Result := Result + RootNodeToString(TreeList.Items[i]);
end;
end;
function RootNodeFromName(TreeList : TcxTreeList; AName : String) : TcxTreeListNode;
// Finds the RootNode having a given name or NIL if not found
var
i : Integer;
begin
// First remove the square brackets, if any
if AName[1] = '[' then
Delete(AName, 1, 1);
if AName[Length(AName)] = ']' then
Delete(AName, Length(AName), 1);
// Next, look for AName in TreeList
for i := 0 to TreeList.Count - 1 do begin
Result := TreeList.Items[i];
if CompareText(Result.Values[iNameCol], AName) = 0 then exit; //CompareText is case-insensitive
end;
Result := Nil; // if we get to here, we didn't find it
end;
function ChildNodeFromName(RootNode : TcxTreeListNode; const AName : String) : TcxTreeListNode;
// Finds the ChildNode (of a RootNode) having a given name or NIL if not found
var
i : Integer;
begin
for i := 0 to RootNode.Count - 1 do begin
Result := RootNode.Items[i];
if CompareText(Result.Values[iNameCol], AName) = 0 then exit; //CompareText is case-insensitive
end;
Result := Nil; // if we get to here, we didn't find it
end;
procedure ClearChecks(TreeList : TcxTreeList; ClearChildren : Boolean);
// Clears all the checkmark in a cxTreeList
var
i,
j : Integer;
RootNode,
ANode : TcxTreeListNode;
begin
// This clears the checkmarks from all the Root nodes and, optionally,
// their children
TreeList.BeginUpdate;
try
for i := 0 to TreeList.Count - 1 do begin
RootNode := TreeList.Items[i];
RootNode.Values[iCheckCol] := False;
for j := 0 to RootNode.Count - 1 do begin
ANode := RootNode.Items[j];
ANode.Values[iCheckCol] := False;
end;
end;
finally
TreeList.EndUpdate;
end;
end;
procedure LoadTreeListChecksFromString(TreeList : TcxTreeList; const Input : String);
// This clears the TreeList's checkmarks and then sets the checkmarks
// from the Input string.
var
RootKey,
SubKey : String;
RootNode,
ChildNode : TcxTreeListNode;
TL : TStringList;
i : Integer;
begin
TreeList.BeginUpdate;
try
// First, clear the treelist's checkmarks
ClearChecks(TreeList, True);
// Next load the Input string into a TStringList to split it into a series
// of Root keys and Child keys
TL := TStringList.Create;
try
TL.CommaText := Input;
// The i variable will be used to iterate through the contents of the StringList
i := 0;
while i <= TL.Count - 1 do begin
// The first string in TL should be Root key
RootKey := TL[i];
RootNode := RootNodeFromName(TreeList, RootKey);
Assert(RootNode <> Nil); // will raise exception if RootNode not found
// The question does not say what should happen about the checkmark on the root nodes
Inc(i);
// Now, scan down the entries below the Root key and process retrive each if its sub-keys;
// stop when we get to the next Root key or reach the end of the Stringlist
while (i <= TL.Count - 1) and (Pos('[', TL[i]) <> 1) do begin
SubKey := TL[i];
ChildNode := ChildNodeFromName(RootNode, SubKey);
ChildNode.Values[iCheckCol] := True;
Inc(i);
end;
end;
finally
TL.Free;
end;
finally
TreeList.EndUpdate;
end;
end;
procedure TForm1.SetUpTreeList;
// This sets up the form' cxTreeList with some Root nodes and Child nodes
// Some of the ChildNode's checkmarks are set to save having to click around
// to set things up manually
var
i,
j : Integer;
RootNode,
ANode : TcxTreeListNode;
begin
for i := 0 to 3 do begin
RootNode := cxTreeList1.Add;
RootNode.AssignValues([Odd(i), 'RT' + IntToStr(i + 1)]);
for j := 0 to 4 do begin
ANode := RootNode.AddChild;
ANode.AssignValues([Odd(i + j), Char(j + Ord('A'))]);
end;
RootNode.Expand(True);
end;
edSavedKeys.Text := TreeListNodesToString(cxTreeList1);
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
SetUpTreeList;
end;
procedure TForm1.btnClearClick(Sender: TObject);
begin
ClearChecks(cxTreeList1, True);
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
SetNodeChecked(cxTreeList1.FocusedNode, not cxTreeList1.FocusedNode.Values[iCheckCol]);
end;
procedure TForm1.SetNodeChecked(Node : TcxTreeListNode; Value : Boolean);
begin
if Node = Nil then exit; // do nothing
Node.Values[iCheckCol] := Value;
end;
procedure TForm1.btnLoadClick(Sender: TObject);
begin
ClearChecks(cxTreeList1, True);
LoadTreeListChecksFromString(cxTreeList1, edSavedKeys.Text);
end;
end.
原始答案
afaik设置未绑定cxTreeList的复选框列的最简单方法是将该列中的值设置为True或False。因此，假设您的CheckBox列cxTreeList是列0，您可以简单地执行此操作
procedure TForm1.SetNodeChecked(Node : TcxTreeListNode; Value : Boolean);
begin
if Node = Nil then exit; // do nothing
Node.Values[0] := Value;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
// toggle the checkbox of the focused node using code
SetNodeChecked(cxTreeList1.FocusedNode, not cxTreeList1.FocusedNode.Values[0]);
end;
我假设您可以将其编织到现有代码中。我还没有真正研究过，但是怀疑您可以简化很多。