Správa vlastností prezentace v .NET

Úvod

Aspose.Slides for .NET supports two types of document properties: Built-in and Custom. Both of these property types can easily be accessed and managed using the Aspose.Slides for .NET API.

Aspose.Slides allows you to work with presentation document properties through the IDocumentProperties interface. An instance of this interface is returned by the Presentation.DocumentProperties property. The following examples show how to read, modify, and manage these properties.

Please note that the Application and Producer fields cannot be modified, as these fields will always display “Aspose Ltd.” and “Aspose.Slides for .NET x.x.x”.

Správa vlastností prezentace

Microsoft PowerPoint provides a feature for adding properties to presentation files. These document properties allow useful information to be stored along with the files. There are two types of document properties:

• System-defined (built-in) properties
• User-defined (custom) properties

Built-in properties contain general information about the document, such as the document title, author’s name, document statistics, and more.

Custom properties are defined by users as Name/Value pairs, where both the name and the value are user-specified.

Using Aspose.Slides for .NET, developers can access and modify both built-in and custom properties.

Microsoft PowerPoint allows users to manage document properties by clicking the Office icon, then selecting File → Info → Properties. After choosing Advanced Properties, a dialog appears where you can manage all document properties of the presentation file.

In the Properties dialog, there are several tabs, such as General, Summary, Statistics, Contents, and Custom. Each tab provides options for configuring specific types of information related to the PowerPoint file. The Custom tab is used to manage user-defined properties.

Přístup k vestavěným vlastnostem

These properties, as exposed by the IDocumentProperties interface, include: Creator (Author), Description, Keywords, Created (Creation Date), Modified (Modification Date), Printed (Last Print Date), LastModifiedBy, SharedDoc (indicates whether the document is shared between different producers), PresentationFormat, Subject, Title, and more.

// Vytvořte instanci třídy Presentation, která představuje soubor prezentace.
using Presentation presentation = new Presentation("AccessBuiltInProperties.pptx");

// Get a reference to the object of type IDocumentProperties associated with the presentation.
IDocumentProperties documentProperties = presentation.DocumentProperties;

// Display the Built-in properties.
Console.WriteLine("Category : " + documentProperties.Category);
Console.WriteLine("Content status : " + documentProperties.ContentStatus);
Console.WriteLine("Creation date : " + documentProperties.CreatedTime);
Console.WriteLine("Author : " + documentProperties.Author);
Console.WriteLine("Comments : " + documentProperties.Comments);
Console.WriteLine("Key words : " + documentProperties.Keywords);
Console.WriteLine("Last modified by : " + documentProperties.LastSavedBy);
Console.WriteLine("Manager : " + documentProperties.Manager);
Console.WriteLine("Modified date : " + documentProperties.LastSavedTime);
Console.WriteLine("Presentation format : " + documentProperties.PresentationFormat);
Console.WriteLine("Last print date : " + documentProperties.LastPrinted);
Console.WriteLine("Is shared between producers : " + documentProperties.SharedDoc);
Console.WriteLine("Subject : " + documentProperties.Subject);
Console.WriteLine("Title : " + documentProperties.Title);

Úprava vestavěných vlastností

Modifying the built-in properties of presentation files is just as easy as accessing them. You can simply assign a string value to any desired property, and the property’s value will be updated. In the example below, we demonstrate how to modify the built-in document properties of a presentation file.

// Vytvořte instanci třídy Presentation, která představuje soubor prezentace.
using Presentation presentation = new Presentation("ModifyBuiltInProperties.pptx");

// Získejte referenci na objekt typu IDocumentProperties spojený s prezentací.
IDocumentProperties documentProperties = presentation.DocumentProperties;

// Nastavte vestavěné vlastnosti.
documentProperties.Author = "Aspose.Slides for .NET";
documentProperties.Title = "Manage PowerPoint Presentation Properties";
documentProperties.Subject = "Modify Built-in Properties";
documentProperties.Comments = "Aspose description";
documentProperties.Manager = "Aspose manager";

// Uložte prezentaci do souboru.
presentation.Save("DocumentProperties_output.pptx", SaveFormat.Pptx);

Přidání vlastních vlastností prezentace

Custom presentation properties enable developers to store additional metadata or specific information within a presentation file. Aspose.Slides makes it easy to create and manage these custom properties programmatically. The following examples demonstrate how to add custom properties to your presentations.

// Vytvořte instanci třídy Presentation.
using Presentation presentation = new Presentation();

// Získejte referenci na objekt typu IDocumentProperties spojený s prezentací.
IDocumentProperties documentProperties = presentation.DocumentProperties;

// Přidejte vlastní vlastnosti.
documentProperties["Reviewed by"] = "John Smith";
documentProperties["Confidentiality level"] = "Internal";
documentProperties["Document version"] = 2;

// Uložte prezentaci do souboru.
presentation.Save("CustomDocumentProperties_output.pptx", SaveFormat.Pptx);

Přístup a úprava vlastních vlastností

Aspose.Slides also allows developers to access existing custom properties and modify their values easily. This functionality helps maintain accurate metadata and supports dynamic updates based on user input or business logic. The examples below illustrate how to retrieve and update custom property values within a presentation.

// Vytvořte instanci třídy Presentation, která představuje soubor PPTX.
using Presentation presentation = new Presentation("AccessAndModifyProperties.pptx");

// Get a reference to the object of type IDocumentProperties associated with the presentation.
IDocumentProperties documentProperties = presentation.DocumentProperties;

// Access and modify the custom properties.
for (int i = 0; i < documentProperties.CountOfCustomProperties; i++)
{
    string propertyName = documentProperties.GetCustomPropertyName(i);
    object propertyValue = documentProperties[propertyName];

    // Zobrazte název a hodnotu vlastní vlastnosti.
    Console.WriteLine("Custom property name : " + propertyName);
    Console.WriteLine("Custom property value : " + propertyValue);

    // Upravit hodnotu vlastní vlastnosti.
    documentProperties[propertyName] = "New Value " + (i + 1);
}

// Save the presentation to a file.
presentation.Save("CustomProperties_output.pptx", SaveFormat.Pptx);

Ukázkový příklad

Try the View & Edit PowerPoint Metadata online app to see how to work with document properties using the Aspose.Slides API:

*FAQ

Jak mohu odstranit vestavěnou vlastnost z prezentace?

Built-in properties are an integral part of the presentation and cannot be removed entirely. However, you can either change their values or set them to empty if allowed by the specific property.

Co se stane, pokud přidám vlastní vlastnost, která již existuje?

If you add a custom property that already exists, its existing value will be overwritten with the new one. You do not need to remove or check the property beforehand, as Aspose.Slides automatically updates the property’s value.

Mohu přistupovat k vlastnostem prezentace bez úplného načtení prezentace?

Yes, you can access presentation properties without fully loading the presentation by using the GetPresentationInfo method from the PresentationFactory class. Then, utilize the ReadDocumentProperties method provided by the IPresentationInfo interface to read the properties efficiently, saving memory and improving performance.