如何读写XML文档节点值？

I want to read some nodes of a XML file and show their values in some custom input fields. User can then change the values if needed, and by clicking the Next button these values should be saved back to the XML.

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值，单击“下一步”按钮，这些值应保存回XML。

How to do this in InnoSetup script ?

如何在InnoSetup脚本中执行此操作？

1 个解决方案

#1

Use the CreateOleObject function to instantiate the standard MSXML2.DOMDocument COM object. The following script shows how to load and save a text value for a single node from the XML file posted below (the script itself was inspired by the examples from MSDN):

使用CreateOleObject函数来实例化标准MSXML2.DOMDocument COM对象。以下脚本显示如何从下面发布的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）：

[Setup]
AppName=My Program
AppVersion=1.5
DefaultDirName={pf}\My Program
DefaultGroupName=My Program
UninstallDisplayIcon={app}\MyProg.exe
Compression=lzma2
SolidCompression=yes
OutputDir=userdocs:Inno Setup Examples Output

[Files]
Source: "MyProg.exe"; DestDir: "{app}"
Source: "MyProg.chm"; DestDir: "{app}"

[Icons]
Name: "{group}\My Program"; Filename: "{app}\MyProg.exe"

[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;

Here is the XML file used in the script:

以下是脚本中使用的XML文件：

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