qlineedit.3qt

linux下GUI编程工具qt的在线连接帮助手册

See also text and maxLength.
.SH "QLineEdit::QLineEdit ( const QString & contents, QWidget * parent, const char * name = 0 )"
Constructs a line edit containing the text \fIcontents\fR.
.PP
The cursor position is set to the end of the line and the maximum text length to 32767 characters.
.PP
The \fIparent\fR and \fIname\fR arguments are sent to the QWidget constructor.
.PP
See also text and maxLength.
.SH "QLineEdit::~QLineEdit ()"
Destroys the line edit.
.SH "int QLineEdit::alignment () const"
Returns the alignment of the line edit. See the "alignment" property for details.
.SH "void QLineEdit::backspace ()"
Deletes the character to the left of the text cursor and moves the cursor one position to the left. If any text has been selected by the user (e.g. by clicking and dragging), the cursor will be put at the beginning of the selected text and the selected text will be removed.
.PP
See also del().
.SH "int QLineEdit::characterAt ( int xpos, QChar * chr ) const"
Returns the index position of the character which is at \fIxpos\fR (in logical coordinates from the left). If \fIchr\fR is not 0, \fC*<em>chr</em>\fR is populated with the character at this position.
.SH "void QLineEdit::clear ()\fC [virtual slot]\fR"
Syntactic sugar for setText( "" ), provided to match no-argument signals.
.SH "void QLineEdit::clearValidator ()\fC [virtual slot]\fR"
This slot is equivalent to setValidator( 0 ).
.SH "void QLineEdit::copy () const\fC [virtual slot]\fR"
Copies the selected text to the clipboard, if there is any, and if echoMode() is Normal.
.PP
See also cut() and paste().
.SH "QPopupMenu * QLineEdit::createPopupMenu ()\fC [virtual protected]\fR"
This function is called to create the popup menu which is shown when the user clicks on the lineedit with the right mouse button. If you want to create a custom popup menu, reimplement this function and return the popup menu you create. The popup menu's ownership is transferred to the caller.
.SH "void QLineEdit::cursorBackward ( bool mark, int steps = 1 )"
Moves the cursor back \fIsteps\fR characters. If \fImark\fR is TRUE each character moved over is added to the selection; if \fImark\fR is FALSE the selection is cleared.
.PP
See also cursorForward().
.SH "void QLineEdit::cursorForward ( bool mark, int steps = 1 )"
Moves the cursor forward \fIsteps\fR characters. If \fImark\fR is TRUE each character moved over is added to the selection; if \fImark\fR is FALSE the selection is cleared.
.PP
See also cursorBackward().
.SH "void QLineEdit::cursorLeft ( bool mark, int steps = 1 )"
\fBThis function is obsolete.\fR It is provided to keep old source working. We strongly advise against using it in new code.
.PP
For compatibilty with older applications only. Use cursorBackward() instead.
.PP
See also cursorBackward().
.SH "int QLineEdit::cursorPosition () const"
Returns the current cursor position for this line edit. See the "cursorPosition" property for details.
.SH "void QLineEdit::cursorRight ( bool mark, int steps = 1 )"
\fBThis function is obsolete.\fR It is provided to keep old source working. We strongly advise against using it in new code.
.PP
Use cursorForward() instead.
.PP
See also cursorForward().
.SH "void QLineEdit::cursorWordBackward ( bool mark )"
Moves the cursor one word backward. If \fImark\fR is TRUE, the word is also selected.
.PP
See also cursorWordForward().
.SH "void QLineEdit::cursorWordForward ( bool mark )"
Moves the cursor one word forward. If \fImark\fR is TRUE, the word is also selected.
.PP
See also cursorWordBackward().
.SH "void QLineEdit::cut ()\fC [virtual slot]\fR"
Copies the selected text to the clipboard and deletes it, if there is any, and if echoMode() is Normal.
.PP
If the current validator disallows deleting the selected text, cut() will copy it but not delete it.
.PP
See also copy() and paste().
.SH "void QLineEdit::del ()"
Deletes the character on the right side of the text cursor. If any text has been selected by the user (e.g. by clicking and dragging), the cursor will be put at the beginning of the selected text and the selected text will be removed.
.PP
See also backspace().
.SH "void QLineEdit::deselect ()\fC [virtual slot]\fR"
De-selects all text (i.e. removes highlighting) and leaves the cursor at the current position.
.PP
See also setSelection() and selectAll().
.SH "QString QLineEdit::displayText () const"
Returns the text that is displayed. See the "displayText" property for details.
.SH "bool QLineEdit::dragEnabled () const"
Returns TRUE if the lineedit starts a drag if the user presses and moves the mouse on some selected text; otherwise returns FALSE. See the "dragEnabled" property for details.
.SH "EchoMode QLineEdit::echoMode () const"
Returns the echo mode of the line edit. See the "echoMode" property for details.
.SH "bool QLineEdit::edited () const"
Returns the edited flag of the line edit. See the "edited" property for details.
.SH "void QLineEdit::end ( bool mark )"
Moves the text cursor to the end of the line. If \fImark\fR is TRUE, text is selected towards the last position; otherwise, any selected text is unselected if the cursor is moved.
.PP
See also home().
.SH "bool QLineEdit::frame () const"
Returns TRUE if the line edit draws itself with a frame; otherwise returns FALSE. See the "frame" property for details.
.SH "bool QLineEdit::getSelection ( int * start, int * end )"
This function sets \fC*<em>start</em>\fR to the position in the text where the selection starts and \fC*<em>end</em>\fR to the position where the selection ends. Returns TRUE if \fIstart\fR and \fIend\fR are not null and if there is some selected text; otherwise returns FALSE.
.PP
See also setSelection().
.SH "bool QLineEdit::hasMarkedText () const"
Returns TRUE if part of the text has been selected by the user (e.g. by clicking and dragging); otherwise returns FALSE. See the "hasMarkedText" property for details.
.SH "bool QLineEdit::hasSelectedText () const"
Returns TRUE if there is any text selected; otherwise returns FALSE. See the "hasSelectedText" property for details.
.SH "void QLineEdit::home ( bool mark )"
Moves the text cursor to the beginning of the line. If \fImark\fR is TRUE, text is selected towards the first position; otherwise, any selected text is unselected if the cursor is moved.
.PP
See also end().
.SH "void QLineEdit::insert ( const QString & newText )\fC [virtual slot]\fR"
Removes any selected text, inserts \fInewText\fR, and validates the result. If it is valid, it sets it as the new contents of the line edit.
.SH "bool QLineEdit::isReadOnly () const"
Returns TRUE if the line edit is read only; otherwise returns FALSE. See the "readOnly" property for details.
.SH "bool QLineEdit::isRedoAvailable () const"
Returns TRUE if redo is available; otherwise returns FALSE. See the "redoAvailable" property for details.
.SH "bool QLineEdit::isUndoAvailable () const"
Returns TRUE if undo is available; otherwise returns FALSE. See the "undoAvailable" property for details.
.SH "void QLineEdit::keyPressEvent ( QKeyEvent * e )\fC [virtual protected]\fR"
Converts key press event \fIe\fR into a line edit action.
.PP
If Return or Enter is pressed and the current text is valid (or can be made valid by the validator), the signal returnPressed is emitted.
.PP
The default key bindings are listed in the detailed description.
.PP
Reimplemented from QWidget.
.SH "QString QLineEdit::markedText () const"
Returns the text selected by the user (e.g. by clicking and dragging), or QString::null if no text is selected. See the "markedText" property for details.
.SH "int QLineEdit::maxLength () const"
Returns the maximum permitted length of the text in the editor. See the "maxLength" property for details.
.SH "QSize QLineEdit::minimumSizeHint () const\fC [virtual]\fR"
Returns a minimum size for the line edit.
.PP
The width returned is enough for at least one character.
.PP
Reimplemented from QWidget.
.SH "void QLineEdit::paste ()\fC [virtual slot]\fR"
Inserts the clipboard's text at the cursor position, deleting any selected text.
.PP
If the end result is not acceptable for the current validator, nothing happens.
.PP
See also copy() and cut().
.SH "void QLineEdit::redo ()\fC [virtual slot]\fR"
Redoes the last operation
.SH "void QLineEdit::repaintArea ( int from, int to )\fC [protected]\fR"
\fBThis function is obsolete.\fR It is provided to keep old source working. We strongly advise against using it in new code.
.PP
Repaints all characters from \fIfrom\fR to \fIto\fR. If cursorPos is between from and to, ensures that cursorPos is visible.
.SH "void QLineEdit::returnPressed ()\fC [signal]\fR"
This signal is emitted when the Return or Enter key is pressed.
.PP
Example: popup/popup.cpp.
.SH "void QLineEdit::selectAll ()\fC [virtual slot]\fR"
Selects all the text (i.e. highlights it) and moves the cursor to the end. This is useful when a default value has been inserted because if the user types before clicking on the widget, the selected text will be erased.
.PP
See also setSelection() and deselect().
.SH "QString QLineEdit::selectedText () const"
Returns any text selected by the user or QString::null. See the "selectedText" property for details.
.SH "void QLineEdit::selectionChanged ()\fC [signal]\fR"
This signal is emitted whenever the selection changes.
.PP
See also hasSelectedText and selectedText.
.SH "void QLineEdit::setAlignment ( int flag )\fC [virtual slot]\fR"
Sets the alignment of the line edit to \fIflag\fR. See the "alignment" property for details.
.SH "void QLineEdit::setCursorPosition ( int )\fC [virtual slot]\fR"
Sets the current cursor position for this line edit. See the "cursorPosition" property for details.
.SH "void QLineEdit::setDragEnabled ( bool b )\fC [virtual slot]\fR"
Sets whether the lineedit starts a drag if the user presses and moves the mouse on some selected text to \fIb\fR. See the "dragEnabled" property for details.
.SH "void QLineEdit::setEchoMode ( EchoMode )\fC [virtual slot]\fR"
Sets the echo mode of the line edit. See the "echoMode" property for details.
.SH "void QLineEdit::setEdited ( bool )"
Sets the edited flag of the line edit. See the "edited" property for details.
.SH "void QLineEdit::setFrame ( bool )\fC [virtual slot]\fR"
Sets whether the line edit draws itself with a frame. See the "frame" property for details.
.SH "void QLineEdit::setMaxLength ( int )\fC [virtual slot]\fR"
Sets the maximum permitted length of the text in the editor. See the "maxLength" property for details.
.SH "void QLineEdit::setReadOnly ( bool )\fC [virtual slot]\fR"
Sets whether the line edit is read only. See the "readOnly" property for details.
.SH "void QLineEdit::setSelection ( int start, int length )\fC [virtual slot]\fR"
Sets the selected area of this line edit to start at position \fIstart\fR and be \fIlength\fR characters long.
.PP
See also deselect(), selectAll() and getSelection().
.SH "void QLineEdit::setText ( const QString & )\fC [virtual slot]\fR"
Sets the text in the line. See the "text" property for details.
.SH "void QLineEdit::setValidator ( const QValidator * v )\fC [virtual slot]\fR"
Sets this line edit to accept input only as accepted by the validator, \fIv\fR, allowing arbitrary constraints on the text which may be entered.
.PP
If \fIv\fR == 0, setValidator() removes the current input validator. The initial setting is to have no input validator (i.e. any input is accepted up to maxLength()).
.PP
See also validator() and QValidator.
.PP
Examples:
.)l lineedits/lineedits.cpp and wizard/wizard.cpp.
.SH "QSize QLineEdit::sizeHint () const\fC [virtual]\fR"
Returns a recommended size for the widget.
.PP
The width returned, in pixels, is usually enough for about 15 to 20 characters.
.PP
Example: addressbook/centralwidget.cpp.
.SH "QString QLineEdit::text () const"
Returns the text in the line. See the "text" property for details.
.SH "void QLineEdit::textChanged ( const QString & )\fC [signal]\fR"
This signal is emitted whenever the text changes. The argument is the new text.
.PP
Examples:
.)l wizard/wizard.cpp and xform/xform.cpp.
.SH "void QLineEdit::undo ()\fC [virtual slot]\fR"
Undoes the last operation
.SH "bool QLineEdit::validateAndSet ( const QString & newText, int newPos, int newMarkAnchor, int newMarkDrag )"
Validates and perhaps sets this line edit to contain \fInewText\fR with the cursor at position \fInewPos\fR, with selected text from \fInewMarkAnchor\fR to \fInewMarkDrag\fR. Returns TRUE if it changes the line edit; otherwise returns FALSE.
.PP
Linebreaks in \fInewText\fR are converted to spaces, and the text is truncated to maxLength() before its validity is tested.
.PP
Repaints and emits textChanged() if appropriate.
.SH "const QValidator * QLineEdit::validator () const"
Returns a pointer to the current input validator, or 0 if no validator has been set.
.PP
See also setValidator().
.PP
Example: wizard/wizard.cpp.
.SS "Property Documentation"
.SH "Alignment alignment"
This property holds the alignment of the line edit.
.PP
Possible Values are Qt::AlignAuto, Qt::AlignLeft, Qt::AlignRight and Qt::AlignHCenter.
.PP
Attempting to set the alignment to an illegal flag combination does nothing.
.PP
See also Qt::AlignmentFlags.
.PP
Set this property's value with setAlignment() and get this property's value with alignment().
.SH "int cursorPosition"
This property holds the current cursor position for this line edit.
.PP
Setting the cursor position causes a repaint when appropriate.
.PP
Set this property's value with setCursorPosition() and get this property's value with cursorPosition().
.SH "QString displayText"
This property holds the text that is displayed.
.PP
If EchoMode is Normal this returns the same as text(); if EchoMode is Password it returns a string of asterisks the text().length() characters long, e.g. "******"; if EchoMode is NoEcho returns an empty string, "".
.PP
See also echoMode, text and EchoMode.
.PP
Get this property's value with displayText().
.SH "bool dragEnabled"
This property holds whether the lineedit starts a drag if the user presses and moves the mouse on some selected text.
.PP
Set this property's value with setDragEnabled() and get this property's value with dragEnabled().
.SH "EchoMode echoMode"
This property holds the echo mode of the line edit.
.PP
The initial setting is Normal, but QLineEdit also supports NoEcho and Password modes.
.PP
The widget's display and the ability to copy or drag the text is affected by this setting.
.PP
See also EchoMode and displayText.
.PP
Set this property's value with setEchoMode() and get this property's value with echoMode().
.SH "bool edited"
This property holds the edited flag of the line edit.
.PP
The edited flag is never read by QLineEdit; it has a default value of FALSE and is changed to TRUE whenever the user changes the line edit's contents.
.PP
This is useful for things that need to provide a default value but cannot find the default at once. Just start the line edit without the best default; when the default is known, check the edited() return value and set the line edit's contents if the user has not started editing the line edit.
.PP
Calling setText() resets the edited flag to FALSE.
.PP
Set this property's value with setEdited() and get this property's value with edited().
.SH "bool frame"
This property holds whether the line edit draws itself with a frame.
.PP
If enabled (the default) the line edit draws itself inside a two-pixel frame, otherwise the line edit draws itself without any frame.
.PP
Set this property's value with setFrame() and get this property's value with frame().
.SH "bool hasMarkedText"
\fBThis function is obsolete.\fR It is provided to keep old source working. We strongly advise against using it in new code.
.PP
This property holds whether part of the text has been selected by the user (e.g. by clicking and dragging).
.PP
Get this property's value with hasMarkedText().
.PP
See also selectedText.
.SH "bool hasSelectedText"
This property holds whether there is any text selected.
.PP
hasSelectedText() returns TRUE if some or all of the text has been selected by the user (e.g. by clicking and dragging); otherwise returns FALSE.
.PP
See also selectedText.
.PP
Get this property's value with hasSelectedText().
.SH "QString markedText"
\fBThis function is obsolete.\fR It is provided to keep old source working. We strongly advise against using it in new code.
.PP
This property holds the text selected by the user (e.g. by clicking and dragging), or QString::null if no text is selected.
.PP
Get this property's value with markedText().
.PP
See also hasSelectedText.
.SH "int maxLength"
This property holds the maximum permitted length of the text in the editor.
.PP
If the text is too long, it is truncated at the limit.
.PP
If truncation occurs any selected text will be unselected, the cursor position is set to 0 and the first part of the string is shown.
.PP
Set this property's value with setMaxLength() and get this property's value with maxLength().
.SH "bool readOnly"
This property holds whether the line edit is read only.
.PP
In read-only mode, the user can still copy the text to the clipboard or drag-and-drop the text, but cannot edit it.
.PP
QLineEdit does not show a cursor in read-only mode.
.PP
See also enabled.
.PP
Set this property's value with setReadOnly() and get this property's value with isReadOnly().
.SH "bool redoAvailable"
This property holds whether redo is available.
.PP
Get this property's value with isRedoAvailable().
.SH "QString selectedText"
This property holds any text selected by the user or QString::null.
.PP
Get this property's value with selectedText().
.PP
See also hasSelectedText.
.SH "QString text"
This property holds the text in the line.
.PP
Setting this property clears the selection and moves the cursor to the end of the line.
.PP
The text is truncated to maxLength() length.
.PP
Set this property's value with setText() and get this property's value with text().
.SH "bool undoAvailable"
This property holds whether undo is available.
.PP
Get this property's value with isUndoAvailable().

.SH "SEE ALSO"
.BR http://doc.trolltech.com/qlineedit.html
.BR http://www.trolltech.com/faq/tech.html
.SH COPYRIGHT
Copyright 1992-2001 Trolltech AS, http://www.trolltech.com.  See the
license file included in the distribution for a complete license
statement.
.SH AUTHOR
Generated automatically from the source code.
.SH BUGS
If you find a bug in Qt, please report it as described in
.BR http://doc.trolltech.com/bughowto.html .
Good bug reports help us to help you. Thank you.
.P
The definitive Qt documentation is provided in HTML format; it is
located at $QTDIR/doc/html and can be read using Qt Assistant or with
a web browser. This man page is provided as a convenience for those
users who prefer man pages, although this format is not officially
supported by Trolltech. 
.P
If you find errors in this manual page, please report them to
.BR [e-mail] .
Please include the name of the manual page (qlineedit.3qt) and the Qt
version (3.0.0).