SerialPort.ReadTo Method (String)


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Reads a string up to the specified value in the input buffer.

Namespace:   System.IO.Ports
Assembly:  System (in System.dll)

public string ReadTo(
	string value


Type: System.String

A value that indicates where the read operation stops.

Return Value

Type: System.String

The contents of the input buffer up to the specified value.

Exception Condition

The length of the value parameter is 0.


The value parameter is null.


The specified port is not open.


The operation did not complete before the time-out period ended.

This method reads a string up to the specified value. While the returned string does not include the value, the value is removed from the input buffer.

If it is necessary to switch between reading text and reading binary data from the stream, select a protocol that carefully defines the boundary between text and binary data, such as manually reading bytes and decoding the data.


Because the SerialPort class buffers data, and the stream contained in the BaseStream property does not, the two might conflict about how many bytes are available to read. The BytesToRead property can indicate that there are bytes to read, but these bytes might not be accessible to the stream contained in the BaseStream property because they have been buffered to the SerialPort class.

.NET Framework
Available since 2.0
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