如何檢測文件是否要安裝（或替換）？

Question

我有一個Inno安裝腳本，我需要在安裝或替換特定文件之前執行自定義操作。

的documentation狀態：

如果安裝程序已經確定它不應該被處理記錄A BeforeInstall或AfterInstall函數沒有被調用。

所以我想我可以用BeforeInstall指定安裝文件之前，應當做什麼，但似乎Inno Setup的需要安裝的文件或不決定調用BeforeInstall功能後，所以這函數實際上每次都被調用。

如何在安裝文件之前執行操作，但如果文件未安裝（例如，因爲其版本未更改），該如何執行操作？

編輯：

下面的代碼的相關部分：

... 
[Files] 
... 
Source: "..\bin\{#BuildConfig}\FooBar.dll"; DestDir: "{app}"; Flags: uninsrestartdelete; BeforeInstall: PrepareInstallFooBar 

... 
[Code] 
... 
procedure PrepareInstallFooBar(); 
begin 
    Log(Format('BeforeInstall: %s', [CurrentFileName])); 
    ... 
end; 

... 

下面是該日誌中顯示：

... 
2014-03-28 10:40:46.778 BeforeInstall: {app}\FooBar.dll 
2014-03-28 10:40:46.778 -- File entry -- 
2014-03-28 10:40:46.778 Dest filename: C:\Users\tom\AppData\Local\MyApp\bin\FooBar.dll 
2014-03-28 10:40:46.778 Time stamp of our file: 2014-03-28 10:35:10.000 
2014-03-28 10:40:46.778 Dest file exists. 
2014-03-28 10:40:46.778 Time stamp of existing file: 2014-03-28 10:35:10.000 
2014-03-28 10:40:46.778 Version of our file: 1.0.0.0 
2014-03-28 10:40:46.778 Version of existing file: 1.0.0.0 
2014-03-28 10:40:46.778 Same version. Skipping. 
... 

Answer 1

因爲我不能讓Inno Setup的行爲方式我想，我最終自己在Check函數中檢查了自己的版本：

... 
[Files] 
Source: "..\bin\{#BuildConfig}\FooBar.dll"; DestDir: "{app}"; Flags: uninsrestartdelete; Check: ShouldInstallFooBar; BeforeInstall: BeforeInstallFooBar; 
... 

[Code] 
function ShouldInstallFooBar() : Boolean; 
var 
    fooBarTempPath: String; 
    installedFooBarPath: String; 
    newFooBarVersion: String; 
    installedFooBarVersion: String; 
begin 
    installedFooBarPath := ExpandConstant('{app}\FooBar.dll'); 
    if FileExists(installedFooBarPath) then begin 
    // Get version of currently installed file 
    if GetVersionNumbersString(installedFooBarPath, installedFooBarVersion) then begin 
     Log('File already exists; version = ' + installedFooBarVersion); 
     // Extract new file and get its version 
     ExtractTemporaryFile('FooBar.dll'); 
     fooBarTempPath := ExpandConstant('{tmp}\FooBar.dll'); 
     if GetVersionNumbersString(fooBarTempPath, newFooBarVersion) then begin 
     Log('New version = ' + newFooBarVersion); 
     if newFooBarVersion <> installedFooBarVersion then begin 
      fooBarShouldBeInstalled := true; 
     end else begin 
      fooBarShouldBeInstalled := false; 
     end; 
     end else begin 
     // Failed to get version for new file; assume it's different and install it 
     fooBarShouldBeInstalled := true; 
     end; 
    end else begin 
     // Failed to get version for existing file; assume it's different and install the new one 
     fooBarShouldBeInstalled := true; 
    end; 
    end else begin 
    // File doesn't exist, install it 
    fooBarShouldBeInstalled := true; 
    end; 
    Result := fooBarShouldBeInstalled; 
end; 

procedure BeforeInstallFooBar(); 
begin 
    // what I need to do before the file is installed... 
end; 

...