Using Type dynamic C Programming GuideC 4 introduces a new type, dynamic. The type is a static type, but an object of type dynamic bypasses static type checking. In most cases, it functions like it has type object. At compile time, an element that is typed as dynamic is assumed to support any operation. Download content for Azure, ASP. NET, Office, SQL Server, SharePoint Server and other Microsoft technologies in ebook formats. Reference, guide, and stepbystep. Interoperability enables you to preserve and take advantage of existing investments in unmanaged code. Code that runs under the control of the common language runtime. Therefore, you do not have to be concerned about whether the object gets its value from a COM API, from a dynamic language such as Iron. Python, from the HTML Document Object Model DOM, from reflection, or from somewhere else in the program. Programming Microsoft Office 365However, if the code is not valid, errors are caught at run time. For example, if instance method example. Method. 1 in the following code has only one parameter, the compiler recognizes that the first call to the method, ec. Method. 11. 0, 4, is not valid because it contains two arguments. The call causes a compiler error. The second call to the method, dynamicec. Method. 11. 0, 4, is not checked by the compiler because the type of dynamicec is dynamic. Therefore, no compiler error is reported. However, the error does not escape notice indefinitely. Note Many Microsoft Office programs use the term macro to refer to VBA code. This can be confusing to Access users because, in Access, the term macro refers to a. It is caught at run time and causes a run time exception. Mainstring args. Example. Class ec new Example. Class. The following call to example. Method. 1 causes a compiler error. Method. 1 has only one parameter. Uncomment the line. Method. 11. 0, 4. Example. Class. The following line is not identified as an error by the. Method. 11. 0, 4. The following calls also do not cause compiler errors, whether. Methodsome argument, 7, null. Method. class Example. Class. public Example. Class. public Example. Classint v. Method. 1int i. Method. 2string str. The role of the compiler in these examples is to package together information about what each statement is proposing to do to the object or expression that is typed as dynamic. At run time, the stored information is examined, and any statement that is not valid causes a run time exception. The result of most dynamic operations is itself dynamic. For example, if you rest the mouse pointer over the use of test. Sum in the following example, Intelli. Sense displays the type local variable dynamic test. Sum. dynamic d 1. Sum d 3. Rest the mouse pointer over test. Sum in the following statement. System. Console. Write. Linetest. Sum. Operations in which the result is not dynamic include conversions from dynamic to another type, and constructor calls that include arguments of type dynamic. For example, the type of test. Instance in the following declaration is Example. Class, not dynamic. Instance new Example. Classd. Conversion examples are shown in the following section, Conversions. Conversions Conversions between dynamic objects and other types are easy. This enables the developer to switch between dynamic and non dynamic behavior. Any object can be converted to dynamic type implicitly, as shown in the following examples. System. Date. Time. Today. dynamic d. System. Diagnostics. Process. Get. Processes. Conversely, an implicit conversion can be dynamically applied to any expression of type dynamic. Date. Time dt d. System. Diagnostics. Process procs d. Overload Resolution with Arguments of Type dynamic Overload resolution occurs at run time instead of at compile time if one or more of the arguments in a method call have the type dynamic, or if the receiver of the method call is of type dynamic. In the following example, if the only accessible example. Method. 2 method is defined to take a string argument, sending d. Overload resolution fails at run time because the run time type of d. Method. 2 requires a string. Valid. ec. example. Method. 2a string. The following statement does not cause a compiler error, even though ec is not. A run time exception is raised because the run time type of d. Method. 2d. 1. The following statement does cause a compiler error. Method. 27. Dynamic Language Runtime The dynamic language runtime DLR is a new API in. NET Framework 4. It provides the infrastructure that supports the dynamic type in C, and also the implementation of dynamic programming languages such as Iron. Python and Iron. Ruby. For more information about the DLR, see Dynamic Language Runtime Overview. C 4 includes several features that improve the experience of interoperating with COM APIs such as the Office Automation APIs. Among the improvements are the use of the dynamic type, and of named and optional arguments. Many COM methods allow for variation in argument types and return type by designating the types as object. This has necessitated explicit casting of the values to coordinate with strongly typed variables in C. If you compile by using the link C Compiler Options option, the introduction of the dynamic type enables you to treat the occurrences of object in COM signatures as if they were of type dynamic, and thereby to avoid much of the casting. For example, the following statements contrast how you access a cell in a Microsoft Office Excel spreadsheet with the dynamic type and without the dynamic type. Before the introduction of dynamic. Excel. Rangeexcel. App. Cells1, 1. Value. 2 Name. Excel. Range range. Excel. Rangeexcel. App. Cells1, 1. After the introduction of dynamic, the access to the Value property and. Excel. Range are handled by the run time COM binder. App. Cells1, 1. Value Name. Excel. Range range. 20. 10 excel. App. Cells1, 1. Free Microsoft Office Books PDF Download. Download free pdf e. Book Microsoft Office 2. Ultimate Tips Tricks by Matt Smith from Make. Use. Of. com. This guide will show you how to Get the most out of 2. Word with building blocks, present data at a glance with Excels new Sparklines, edit video from within Power. Point, broadcast a Power. Point presentation over the web, live, adding social functionality to Outlook.
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