2.2.4.24.19 Layer::LT_evaluate

LT_evaluate

1 Description
2 Syntax
3 Parameters
4 Return
5 Examples
6 Remark
7 See Also
8 Header to Include
9 Reference

Description

Evaluate an expression with a specific layer as the active layer.

Syntax

BOOL LT_evaluate( LPCSTR lpcszLabTalkExpression, double * lpdbResult )

Parameters

lpcszLabTalkExpression: [input] Pointer to a string containing the expression in LabTalk syntax.
lpdbResult: [output] Pointer to a double value to receive the results.

Return

TRUE if expression is valid, FALSE if expression leads to missing value

Examples

EX1

//Check if the labtalk expression is right.
void Layer_LT_evaluate_ex1()
{
	double vv;
	bool bRet;
	GraphPage gp;
	gp.Create("Origin");
	GraphLayer gl = gp.Layers(0);
	bRet = gl.LT_evaluate("layer.height", &vv);
	if(bRet)
		out_str("The labtalk expression is valid");
	else
		out_str("The labtalk expression is not valid");
	
}