Declaration

Delphi

function SearchKeyString(SearchText, FontName: PAnsiChar; res: PFinderResult; var resLen: Cardinal) : LongBool; stdcall;

ActiveX

HRESULT _stdcall SearchKeyString([in] BSTR SearchString, [in] BSTR FontName, unsigned int* SearchResult, [in, out] unsigned long* ResultLen, [out, retval] VARIANT_BOOL* res);

Arguments

Return value

- will be added soon -

Description

This function is used to search strings in a PDF document. Such a string can be useful as anchor to help setting the correct signature position, for example in a dynamic document, where the content is always different and so the position of the signature does not have fixed coordinates. The function also works well with "invisible" text (white text on white background) or very small text sizes.

The struct, which you get back from the function, contains the coordinates of all positions, at which the search string was found in the document. The values are the coordinates of the top left and bottom right corners as well as the pagenumbers.

C# sample

//STRUCT
public struct SearchResult
{
	public int XmlFieldIndex;
	public int FieldType;
	public int PageNumber;
	public double Left;
	public double Top;
	public double Right;
	public double Bottom;
}
            
//resLen must not be zero
             
uint resLen = maxSearchResultLen;
int size =  Marshal.SizeOf(res[0]);
IntPtr ptr = Marshal.AllocHGlobal((int)resLen*size);
IntPtr tmpPtr = ptr;
uint pstruct = (uint)ptr;
            
bool result = false;
pageList.Items.Clear();
 
try
{
	result = SignAPIv4.SearchKeyString(textBox6.Text, "", ref pstruct, ref resLen);
                
	for (int i=0; i< resLen; i++)
	{
		res[i] = (SearchResult)Marshal.PtrToStructure((IntPtr)pstruct, typeof(SearchResult));
		tmpPtr = (IntPtr)((int)tmpPtr + Marshal.SizeOf(typeof(SearchResult)));
		pstruct = (uint)tmpPtr;
 		pageList.Items.Add(i+1);
	}
                
	x1 = res[0].Left();
	y1 = res[0].Top();
	x2 = res[0].Right();
	y2 = res[0].Bottom();
	page = res[0].PageNumber.ToString();
}