xml - 如何在 Inno Setup 中读写 XML 文档节点值？

Question

我想读取 XML 文件的一些节点并在一些自定义输入字段中显示它们的值。然后，用户可以根据需要更改这些值，并通过单击 Next 按钮将这些值保存回 XML。

如何在 Inno Setup 脚本中执行此操作？

Answer 1

使用 CreateOleObject实例化标准的函数MSXML2.DOMDocument对象。以下脚本显示了如何从下面发布的 XML 文件加载和保存单个节点的文本值(脚本本身的灵感来自 MSDN 中的示例):

[Code]
var
  CustomEdit: TEdit;
  CustomPageID: Integer;

function LoadValueFromXML(const AFileName, APath: string): string;
var
  XMLNode: Variant;
  XMLDocument: Variant;  
begin
  Result := '';
  XMLDocument := CreateOleObject('Msxml2.DOMDocument.6.0');
  try
    XMLDocument.async := False;
    XMLDocument.load(AFileName);
    if (XMLDocument.parseError.errorCode <> 0) then
      MsgBox('The XML file could not be parsed. ' + 
        XMLDocument.parseError.reason, mbError, MB_OK)
    else
    begin
      XMLDocument.setProperty('SelectionLanguage', 'XPath');
      XMLNode := XMLDocument.selectSingleNode(APath);
      Result := XMLNode.text;
    end;
  except
    MsgBox('An error occured!' + #13#10 + GetExceptionMessage, mbError, MB_OK);
  end;
end;

procedure SaveValueToXML(const AFileName, APath, AValue: string);
var
  XMLNode: Variant;
  XMLDocument: Variant;  
begin
  XMLDocument := CreateOleObject('Msxml2.DOMDocument.6.0');
  try
    XMLDocument.async := False;
    XMLDocument.load(AFileName);
    if (XMLDocument.parseError.errorCode <> 0) then
      MsgBox('The XML file could not be parsed. ' + 
        XMLDocument.parseError.reason, mbError, MB_OK)
    else
    begin
      XMLDocument.setProperty('SelectionLanguage', 'XPath');
      XMLNode := XMLDocument.selectSingleNode(APath);
      XMLNode.text := AValue;
      XMLDocument.save(AFileName);
    end;
  except
    MsgBox('An error occured!' + #13#10 + GetExceptionMessage, mbError, MB_OK);
  end;
end;

procedure InitializeWizard;
var  
  CustomPage: TWizardPage;
begin
  CustomPage := CreateCustomPage(wpWelcome, 'Custom Page', 
    'Enter the new value that will be saved into the XML file');
  CustomPageID := CustomPage.ID;
  CustomEdit := TEdit.Create(WizardForm);
  CustomEdit.Parent := CustomPage.Surface;
end;

procedure CurPageChanged(CurPageID: Integer);
begin
  if CurPageID = CustomPageID then
    CustomEdit.Text := LoadValueFromXML('C:\Setup.xml', '//Setup/FirstNode');
end;

function NextButtonClick(CurPageID: Integer): Boolean;
begin
  Result := True;
  if CurPageID = CustomPageID then
    SaveValueToXML('C:\Setup.xml', '//Setup/FirstNode', CustomEdit.Text);
end;

这是脚本中使用的 XML 文件:

<?xml version="1.0" encoding="UTF-8"?>
<Setup>
    <FirstNode>First node value!</FirstNode>
    <SecondNode>Second node value!</SecondNode>
</Setup>