Operator Reference

HALCON Operator Reference / Graphics / Text

• HDevelop
• .NET
• Python
• C++
• C

ClassesClasses | | Operators

read_stringT_read_stringReadStringReadStringread_string (Operator)

read_stringT_read_stringReadStringReadStringread_string — Read a string in a text window.

Warning

This operator does not work in an HDevelop graphics window opened with dev_open_window.

Signature

read_string( : : WindowHandle, InString, Length : OutString)

Herror T_read_string(const Htuple WindowHandle, const Htuple InString, const Htuple Length, Htuple* OutString)

void ReadString(const HTuple& WindowHandle, const HTuple& InString, const HTuple& Length, HTuple* OutString)

HString HWindow::ReadString(const HString& InString, Hlong Length) const

HString HWindow::ReadString(const char* InString, Hlong Length) const

HString HWindow::ReadString(const wchar_t* InString, Hlong Length) const   ( Windows only)

static void HOperatorSet.ReadString(HTuple windowHandle, HTuple inString, HTuple length, out HTuple outString)

string HWindow.ReadString(string inString, int length)

def read_string(window_handle: HHandle, in_string: str, length: int) -> str

Description

read_stringread_stringReadStringReadStringread_string reads a string with a predetermined maximum length (LengthLengthLengthlengthlength) from the keyboard in the input window (= output window). The string is read from the current position of the text cursor using the current font. The maximum length has to be small enough to keep the string within the right window boundary. A default string which can be edited or simply accepted by the user may be provided. After text input the text cursor is positioned at the end of the edited string. Commands for editing:

RETURN

finish input

BACKSPACE

delete the character on the left side of the cursor and move the cursor to this position.

The length is stated as number of characters. If 'filename_encoding'"filename_encoding""filename_encoding""filename_encoding""filename_encoding" is set to 'locale'"locale""locale""locale""locale" with set_systemset_systemSetSystemSetSystemset_system, the length is stated in number of bytes.

Execution Information

• Multithreading type: reentrant (runs in parallel with non-exclusive operators).
• Multithreading scope: global (may be called from any thread).
• Processed without parallelization.

Parameters

WindowHandleWindowHandleWindowHandlewindowHandlewindow_handle (input_control)  window → HWindow, HTupleHHandleHTupleHtuple (handle) (IntPtr) (HHandle) (handle)

Window handle.

InStringInStringInStringinStringin_string (input_control)  string → HTuplestrHTupleHtuple (string) (string) (HString) (char*)

Default string (visible before input).

Default: '' "" "" "" ""

LengthLengthLengthlengthlength (input_control)  integer → HTupleintHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

Maximum number of characters.

Default: 32

Restriction: Length > 0 && Length <= 1024

OutStringOutStringOutStringoutStringout_string (output_control)  string → HTuplestrHTupleHtuple (string) (string) (HString) (char*)

Read string.

Result

read_stringread_stringReadStringReadStringread_string returns 2 ( H_MSG_TRUE) if the text window is valid and a string of maximal length fits within the right window boundary. Otherwise an exception is raised.

Possible Predecessors

open_windowopen_windowOpenWindowOpenWindowopen_window, set_fontset_fontSetFontSetFontset_font

Alternatives

read_charread_charReadCharReadCharread_char, fread_stringfread_stringFreadStringFreadStringfread_string, fread_charfread_charFreadCharFreadCharfread_char

See also

set_tpositionset_tpositionSetTpositionSetTpositionset_tposition, new_linenew_lineNewLineNewLinenew_line, open_windowopen_windowOpenWindowOpenWindowopen_window, set_fontset_fontSetFontSetFontset_font, set_colorset_colorSetColorSetColorset_color

Module

Foundation

---

ClassesClasses | | Operators