I'm using the IFilter interface to read the content of files such as .docx, .pdf, etc. For those two types (and others) this already works pretty well, but I was wondering if it is possible to use this mechanism to read the meta data of a jpg file as well.
I created a test image file and added some information to its details (Title, description, ...)
Interestingly, the Windows Indexer is able to find this file using the text that I specified as title. By using the IFilter interface, however, I retrieve only an empty string for my jpeg.
I also tested the command line tool filtdump.exe from here: https://msdn.microsoft.com/en-us/library/windows/desktop/dd940434(v=vs.85).aspx#command_line, which returned the same results as my implementation.
Does anyone know how the Windows indexer is able to see the content and how I couold use the same mechanism to achieve similar results?
I'm not able to save multiple files at a time in delphi save dialog box. Multiple files means I want save files without mentioning anything(or only asterisk) at "filename" field in delphi TsaveDialog. Please let me know how to achieve that.
Of course not, because that is not what it is intended for. You CANNOT obtain multiple filenames from a single save dialog. It only provides one filename at a time. That is by design.
I suspect what you really want is to prompt the user for just a folder path instead. Use the SelectDirectory() function (or the Win32 SHBrowseForFolder() function directly) for that, then you can create whatever files you need in that folder.
The save dialog doesn't save files. It allows the user to select file names. The save dialog doesn't support multiple selection so if you want to have a file dialog that allows multiple selections you need an open dialog. But an open dialog typically is used to select names of existing files, whereas a save dialog can specify a name of a file that does not yet exist.
Wildcards when entered into file dialogs are used to filter the displayed list of files. The file dialog won't return file names containing wildcards.
You imagine using wildcards, but how would you be able to do that and create new files? Wildcards are used to pattern match against existing files.
Maybe what you need is a folder selection dialog. Or perhaps you should ask the user for the name of the "master" file and then you generate the names of the "auxiliary" files using the master file name as a stem. I'm guessing because you've not told us any specifics behind your question.
My advice is to reconsider carefully what you are attempting to achieve. Think of all possible corner cases. Explore what UI idioms are used by other programs. Make sure you understand fully the capability of the file dialog controls. And then design your UI to fit with all of these constraints.
I am using Express Quantum Grid from developer express. From code i came to know that they are storing the user settings using TMemIniFile. I know the sections where they are storing but is there any way to open the Ini file and see the contents? If so where is the file located?
From code I came to know that they are storing the user settings using TMemIniFile.
The constructor of TMemIniFile receives the name of the file that stores the INI file. So, you simply need to find the call to TMemIniFile.Create and your answer will be revealed.
I would like to create a file type with a personal extension by combining two other file types, like .mp3 and .pdf.
Later I need to re-open the custom files I've made and be able to use the included files in my app.
How do I do that on iOS?
One option is to append the data of the two files together. Include a few bytes of data at the start that tell you the size of each and maybe their original filenames. Then when you want to recreate the two files from the one custom one, you read your header to get the sizes and names, then use that info to recreate the original files.
Another option would be to zip the two files together. Just give the zip file your own custom extension.
Another option would be to use an NSFileWrapper. Include the two regular files in the wrapper.
I'm wondering where's the best place to save some simple insensitive data? Like a few URLs and some settings.
Please advise.
If this is a per-user file, you should save it in the current user's profile. For example, on my Windows 7 system, you should use
C:\Users\Andreas Rejbrand\AppData\Local\Your Company Name\Your Product Name\Version
such as
C:\Users\Andreas Rejbrand\AppData\Local\Rejbrand\AlgoSim\2.0
To get the C:\Users\Andreas Rejbrand\AppData\Local path, you use the SHGetSpecialFolderPath function.
Settings, and specifically user-specific settings, can be stored in the registry. Have a look at the Registry unit and the TRegistry object.
Here's some demo code to get you going:
var
r:TRegistry
begin
r:=TRegistry.Create;
try
r.OpenKey('\Software\MyApplication',true);
r.WriteInteger('Setting1',Setting1);
r.WriteString('Setting2',Setting2);
finally
r.Free;
end;
end;
INI file or JSON file or XML file depending on your needs for local usage.
DB is for net usage.
It all depends on the purpose of those settings! If you want XCopy deployment, I would suggest an XML file next to the exe. But if you also need to write to this, you should find a suitable location in the current user's profile or the "all users" profile. The registry (local machine or current user) would also be a good option for simple settings.
Another question is the type of settings that you need to store. If it's simple settings, I generally start with Altova's XMLSpy to generate an XML schema, defining the structure of the settings. Then I use Delphi's XML import wizard to generate code from this schema and just use that generated code. It allows me to modify the structure in an easy way and also makes sure there's at least some documentation (the schema) telling others about the structure. It might sound complex at first, but once you're used to this, it's perfect! No more manual editing of registry settings or forgetting about the structure of your INI files. And no more thinking about writing code to read and write those settings, since Delphi will do that for you!The Registry would also be a good location for settings but not every user will have proper access rights to read from, or write to, the registry which could crash your application. Besides, the registry has some other limitations which makes it unsuitable if you need to store a lot of settings! It would be okay to store a connection string and maybe username and encrypted password for some user account, but if you need to store 40 settings or more, then the Registry becomes unsuitable.The same is true about INI files, which tend to be limited to a maximum size of 64 kilobytes. Of course, you could also store those settings in a regular text file or just some binary file. In the past, I even stored settings inside a ZIP file, because I needed to store dozens of grid-related settings. So each grid would read and write it's settings to some binary stream which would then be stored in an encrypted ZIP file.
There are many options like XML (structured data storage), ini files (simple data), databases or flat files.
I will go for XML's saved with ClientDatasets. They allow lot of options like searching, sorting, usage of the database controls and many more.