AdsBinaryWriter.WritePlcUnicodeString Method
Writes a (unicode) string as a PLC string to the current stream.
Namespace: TwinCAT.Ads
Assembly: TwinCAT.Ads (in TwinCAT.Ads.dll)
Version: 4.3.0.0
Syntax
C#
public void WritePlcUnicodeString(
string value,
int length
)
VB
Public Sub WritePlcUnicodeString (
value As String,
length As Integer
)
Parameters
|
value |
Type: System.String |
|
length |
Type: System.Int32 |
Remarks
This method is meant for writing single string variables defined in the PlcControl format. E.g. to write a 'WSTRING(80)' (byte size is 162) a length of '80' must be given to the 'length' parameter. If the string length is larger or equal than the length parameter, then only length characters are written to the AdsStream (without terminating character). If the string value character count is shorter than the specified length parameter, the string + a terminating \0 will be added to the AdsStream. This method cannot be used for marshalling purposes, for example several fields of a struct, because no filling bytes will be written to the stream. In that case use the WritePlcUnicodeStringFixedLength(String, Int32) method.
Examples
The following code shows how to Read/Write UNICODE string values..
Read/Write Unicode Strings
using (TcAdsClient client = new TcAdsClient())
{
client.Connect(851); // Connect to local port 851 (PLC)
int handle = client.CreateVariableHandle("MAIN.wstring"); // Symbol "wstring" defined in MAIN as WSTRING
try
{
// Read UNICODE String wstring[80]
int byteSize = 2 * 81; // Size of 80 UNICODE chars + /0 (WSTRING[80])
AdsStream readStream = new AdsStream(byteSize);
AdsBinaryReader reader = new AdsBinaryReader(readStream);
client.Read(handle, readStream, 0, byteSize); // Read 2*81 bytes
string value = reader.ReadPlcString(byteSize,Encoding.Unicode);
// Write ANSI String string[80]
AdsStream writeStream = new AdsStream(byteSize);
AdsBinaryWriter writer = new AdsBinaryWriter(writeStream);
value = "Changed";
writer.WritePlcString(value, 80,Encoding.Unicode);
client.Write(handle, writeStream, 0, byteSize);
}
finally
{
client.DeleteVariableHandle(handle);
}
}