You can drag a data source from the Data Sources window onto a form design surface or control. This causes boilerplate code to be generated that displays the data from the data store. The following illustration shows a dataset that has been dropped onto a Windows form. If you select F5 on the application, the data from the underlying database appears in the form's controls. You can create a dataset or an Entity Framework model to use as a data source for a database or database file.
Choose the Database data-source type, and follow the prompts to specify either a new or existing database connection, or a database file. Run the Entity Data Model Wizard to create the entity classes. Add the model as a data source. The generated classes appear in the Data Source Configuration Wizard when you choose the Objects category. To create a data source from a service, run the Data Source Configuration Wizard and choose the Service data-source type.
This is just a shortcut to the Add Service Reference dialog box, which you can also access by right-clicking the project in Solution Explorer and selecting Add service reference. When you create a data source from a service, Visual Studio adds a service reference to your project. Visual Studio also creates proxy objects that correspond to the objects that the service returns.
For example, a service that returns a dataset is represented in your project as a dataset; a service that returns a specific type is represented in your project as the type returned. WCF Data Services.
WCF services. The items that appear in the Data Sources window are dependent on the data that the service returns. Some services might not provide enough information for the Data Source Configuration Wizard to create bindable objects. The resource file format of. For example:. Empty strings that is, a resource whose value is String. Empty are permitted in text files. Starting with. NET Framework 4. NET Core, text files support conditional compilation with the ifdef symbol Each resource requires its own ifdef symbol If you use an ifdef statement and symbol is defined, the associated resource is included in the.
If you use an if! Comments are optional in text files and are preceded either by a semicolon ; or by a pound sign at the beginning of a line. Lines that contain comments can be placed anywhere in the file.
Comments are not included in a compiled. If the text file contains duplicate occurrences of name , Resource File Generator resgen. In addition, an empty string is permitted. Save resources in text file format by using UTF-8 encoding or UTF encoding in either little-endian or big-endian byte order. However, Resource File Generator resgen. If you want Resgen. To embed a resource file in text format into a. NET assembly, you must convert the file to a binary resource. You can then embed the. NET assembly by using a language compiler or embed it in a satellite assembly by using Assembly Linker Al.
The following example uses a resource file in text format named GreetingResources. The text file defines two strings, prompt and greeting , that prompt the user to enter their name and display a greeting.
The following example shows the source code for a console application that uses the. If you are using Visual Basic, and the source code file is named Greeting. If you are using C , and the source code file is named Greeting. Unlike text files, which can only store string resources, XML resource. The resource file data follows the XML header. Its name attribute defines the resource name, and the nested value tag contains the resource value.
For string data, the value tag contains the string. For example, the following data tag defines a string resource named prompt whose value is "Enter your name:". For resource objects, the data tag includes a type attribute that indicates the data type of the resource.
For objects that consist of binary data, the data tag also includes a mimetype attribute, which indicates the base64 type of the binary data. For example, you can create an XML data source that reads the news from reuters. This lets you change the format of the incoming XML into a format more suitable for your application. For more information, use a web search page for??? XML style sheets???. Third, you can use the XPath attribute to provide an XPath expression that filters the data ion the XML file so only certain elements are retrieved.
The most common XPath expression selects the child elements that are immediately beneath the root element, so the root itself isn??? For example, the XPath expression in this figure selects the Category elements. For more information about the XPath expression, see the next figure.
Runat Must specify??? XPath An XPath expression that filters the data used by the data source. For more information about XPath expression. How to use XPath expression for data sources and data binding. You can also change the XPath expression at runtime by setting the data source??? And, finally you can use the XPath method as an alternative to the Eval method in a data binding expression.
The next two examples show how you can specify an attribute. In example 3, all of the products with Category attributes equal to??? The second set of examples show how you can use XPath expression for data binding.
And the expression in example 3 binds to an attribute named Name. Examples of XPath expressions for selecting data. Examples of XPath expressions for data binding.
Example 1: Bind to element content. Example 1: Bind to element content with formatting. Example 1: Bind to an attribute value.
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