Nullreferenceexception which object

Handling an exception can make your code harder to maintain and understand, and can sometimes introduce other bugs. However, there are many situations where handling the error can be useful:. So only nullable reference types must be checked to avoid a NullReferenceException. Since this is a breaking change, it is launched as an opt-in feature.

Home C VB. Object reference not set to an instance of an object An Object is an instance of a Class , it is stored some where in memory. Reference Types Variables in. A NullReferenceException typically reflects developer error and is thrown in the following scenarios: Forgotten to instantiate a reference type. Forgotten to dimension an array before initializing it.

Is thrown by a method that is passed null. Get a null return value from a method, then call a method on the returned type. Using an expression to retrieve a value and, although checking whether the value is null. If the uninitialized object would corrupt the data record, you can remove the previous data before you close the app. You want to report the exception.

For example, if the error was caused by a mistake from the user of your app, you can generate a message to help them supply the correct information. You can also log information about the error to help you fix the problem. Some frameworks, like ASP. NET, have a high-level exception handler that captures all errors to that the app never crashes; in that case, logging the exception might be the only way you can know that it occurs.

Initializes a new instance of the NullReferenceException class, setting the Message property of the new instance to a system-supplied message that describes the error, such as "The value 'null' was found where an instance of an object was required. Initializes a new instance of the NullReferenceException class with serialized data. Initializes a new instance of the NullReferenceException class with a specified error message.

Initializes a new instance of the NullReferenceException class with a specified error message and a reference to the inner exception that is the cause of this exception. Gets the Exception instance that caused the current exception. When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions. When overridden in a derived class, sets the SerializationInfo with information about the exception.

Creates a shallow copy of the current Object. Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception. Feedback will be sent to Microsoft: By pressing the submit button, your feedback will be used to improve Microsoft products and services.

Privacy policy. Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. The exception that is thrown when there is an attempt to dereference a null object reference. SerializableAttribute ComVisibleAttribute. Is this page helpful?

Yes No. Any additional feedback? Skip Submit. NullReferenceException String. NullReferenceException String, Exception. Inherited from Exception. Gets or sets a link to the help file associated with this exception. Gets a message that describes the current exception. Gets or sets the name of the application or the object that causes the error. Do you need your password? Submit your solution! When answering a question please: Read the question carefully.

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