windows Inno Setup - 检查目标中是否存在文件，否则不会中止安装
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Inno Setup - Check if file exist in destination or else if doesn't abort the installation
提问by Dielo
I need my installer to check if a file exists in the destination location, and if is not there, then the installation aborts. My project is a update patch, so I want the installer to avoid installing the update files if the main exe of the application is not in the destination. How can I do this?
我需要我的安装程序检查目标位置中是否存在文件，如果不存在，则安装中止。我的项目是一个更新补丁，所以如果应用程序的主 exe 不在目标中，我希望安装程序避免安装更新文件。我怎样才能做到这一点？
Can someone give an example of code to check file version through the Windows registry?
有人可以举一个通过 Windows 注册表检查文件版本的代码示例吗？
[Files]
Source C:\filename.exe; DestDir {app}; Flags: ignoreversion; BeforeInstall: CheckForFile;
[code]
procedure CheckForFile(): Boolean;
begin
if (FileExists('c:\somefile.exe')) then
begin
MsgBox('File exists, install continues', mbInformation, MB_OK);
Result := True;
end
else
begin
MsgBox('File does not exist, install stops', mbCriticalError, MB_OK);
Result := False;
end;
end;
回答by Miral
Just don't let the user proceed until they pick the correct folder.
只是不要让用户继续，直到他们选择正确的文件夹。
function NextButtonClick(PageId: Integer): Boolean;
begin
Result := True;
if (PageId = wpSelectDir) and not FileExists(ExpandConstant('{app}\yourapp.exe')) then begin
MsgBox('YourApp does not seem to be installed in that folder. Please select the correct folder.', mbError, MB_OK);
Result := False;
exit;
end;
end;
Of course, it's also a good idea to try to automatically pick the correct folder for them, eg. by retrieving the correct location out of the registry.
当然，尝试自动为他们选择正确的文件夹也是一个好主意，例如。通过从注册表中检索正确的位置。
回答by Tanckom
Another solution would be the InitializeSetup():
另一个解决方案是InitializeSetup()：
Credit: Manfred
信用：曼弗雷德
[code]
function InitializeSetup(): Boolean;
begin
if (FileExists(ExpandConstant('{pf}\{#MyAppName}\somefile.exe'))) then
begin
MsgBox('Installation validated', mbInformation, MB_OK);
Result := True;
end
else
begin
MsgBox('Abort installation', mbCriticalError, MB_OK);
Result := False;
end;
end;
