{"id":2125,"date":"2026-06-15T07:48:54","date_gmt":"2026-06-14T23:48:54","guid":{"rendered":"https:\/\/xlwings.net\/blog\/?p=2125"},"modified":"2026-03-28T07:34:27","modified_gmt":"2026-03-28T07:34:27","slug":"how-to-use-applicationhinstanceptr-in-the-xlwings-api-way","status":"publish","type":"post","link":"https:\/\/xlwings.net\/blog\/how-to-use-applicationhinstanceptr-in-the-xlwings-api-way\/","title":{"rendered":"How to use Application.HinstancePtr in the xlwings API way"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">The Application.HinstancePtr member in Excel&#8217;s object model is a property that provides a handle to the instance of the Excel application. In xlwings, this is particularly useful for advanced Windows API interactions or when you need to obtain the window handle (HWND) of the Excel application for integration with other desktop applications or for performing low-level window operations. This property returns a LongPtr value, which is a pointer to the application instance, and it can be accessed to retrieve the window handle for the main Excel window.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Functionality:<\/strong><br>The primary function of HinstancePtr is to return the instance handle of the Excel application. This handle is essential for tasks such as:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Interacting with the Windows API to manipulate Excel windows (e.g., setting focus, resizing, or moving windows programmatically).<\/li>\n\n\n\n<li>Integrating Excel with other applications that require window handles for communication or automation.<\/li>\n\n\n\n<li>Debugging or monitoring Excel&#8217;s window messages in complex automation scenarios.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Syntax:<\/strong><br>In xlwings, you can access the HinstancePtr property through the <code>app<\/code> object, which represents the Excel application. The syntax is straightforward, as it is a read-only property. The call format is:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>instance_handle = app.api.HinstancePtr<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">This returns a Long integer representing the instance handle. Note that <code>app<\/code> is an xlwings App object, and <code>.api<\/code> is used to access the underlying Excel object model. There are no parameters for this property, as it simply retrieves the handle.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Example:<\/strong><br>Here is a practical example of using HinstancePtr in xlwings to obtain the Excel application&#8217;s instance handle and then use it with the Windows API via the <code>ctypes<\/code> library to perform a basic window operation, such as getting the window text. This example assumes you are running on Windows and have the necessary permissions.<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>import xlwings as xw\nimport ctypes\nfrom ctypes import wintypes\n\n# Connect to the active Excel application\napp = xw.apps.active\n\n# Get the instance handle using HinstancePtr\ninstance_handle = app.api.HinstancePtr\nprint(f\"Excel instance handle (HinstancePtr): {instance_handle}\")\n\n# To get the main window handle (HWND), you typically use the Windows API\n# First, define the FindWindowW function from user32.dll\nuser32 = ctypes.WinDLL('user32', use_last_error=True)\nFindWindowW = user32.FindWindowW\nFindWindowW.argtypes = &#91;wintypes.LPCWSTR, wintypes.LPCWSTR]\nFindWindowW.restype = wintypes.HWND\n\n# Use the instance handle to find the Excel window (class name is \"XLMAIN\")\n# Note: HinstancePtr is not directly the HWND, but you can use it in context\n# Here, we find the window by its class name, which is common for Excel\nexcel_hwnd = FindWindowW(\"XLMAIN\", None)\nif excel_hwnd:\n    print(f\"Excel main window handle (HWND): {excel_hwnd}\")\n\n    # Example: Get the window text length\n    GetWindowTextLengthW = user32.GetWindowTextLengthW\n    GetWindowTextLengthW.argtypes = &#91;wintypes.HWND]\n    GetWindowTextLengthW.restype = ctypes.c_int\n\n    text_length = GetWindowTextLengthW(excel_hwnd)\n    print(f\"Length of Excel window title: {text_length}\")\nelse:\n    print(\"Excel window not found.\")<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The Application.HinstancePtr member in Excel&apos;s object model is a property that provides a handle to &#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[25],"tags":[],"class_list":["post-2125","post","type-post","status-publish","format-standard","hentry","category-xlwings-api-reference"],"_links":{"self":[{"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/posts\/2125","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/comments?post=2125"}],"version-history":[{"count":1,"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/posts\/2125\/revisions"}],"predecessor-version":[{"id":3248,"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/posts\/2125\/revisions\/3248"}],"wp:attachment":[{"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/media?parent=2125"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/categories?post=2125"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/tags?post=2125"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}