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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><!-- /home/reggie/tmp/qt-3.0-reggie-5401/qt-x11-commercial-3.0.5/src/sql/qsqlform.cpp:61 --><html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>QSqlForm Class</title><style type="text/css"><!--h3.fn,span.fn { margin-left: 1cm; text-indent: -1cm; }a:link { color: #004faf; text-decoration: none }a:visited { color: #672967; text-decoration: none }body { background: #ffffff; color: black; }--></style></head><body><table border="0" cellpadding="0" cellspacing="0" width="100%"><tr bgcolor="#E5E5E5"><td valign=center> <a href="index.html"><font color="#004faf">Home</font></a> | <a href="classes.html"><font color="#004faf">All Classes</font></a> | <a href="mainclasses.html"><font color="#004faf">Main Classes</font></a> | <a href="annotated.html"><font color="#004faf">Annotated</font></a> | <a href="groups.html"><font color="#004faf">Grouped Classes</font></a> | <a href="functions.html"><font color="#004faf">Functions</font></a></td><td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QSqlForm Class Reference<br><small>[<a href="sql.html">sql module</a>]</small></h1><p>The QSqlForm class creates and manages data entry forms tied to SQLdatabases.<a href="#details">More...</a><p><tt>#include <<a href="qsqlform-h.html">qsqlform.h</a>></tt><p>Inherits <a href="qobject.html">QObject</a>.<p><a href="qsqlform-members.html">List of all member functions.</a><h2>Public Members</h2><ul><li><div class=fn><a href="#QSqlForm"><b>QSqlForm</b></a> ( QObject * parent = 0, const char * name = 0 )</div></li><li><div class=fn><a href="#~QSqlForm"><b>~QSqlForm</b></a> ()</div></li><li><div class=fn>virtual void <a href="#insert"><b>insert</b></a> ( QWidget * widget, const QString & field )</div></li><li><div class=fn>virtual void <a href="#remove-2"><b>remove</b></a> ( const QString & field )</div></li><li><div class=fn>uint <a href="#count"><b>count</b></a> () const</div></li><li><div class=fn>QWidget * <a href="#widget"><b>widget</b></a> ( uint i ) const</div></li><li><div class=fn>QSqlField * <a href="#widgetToField"><b>widgetToField</b></a> ( QWidget * widget ) const</div></li><li><div class=fn>QWidget * <a href="#fieldToWidget"><b>fieldToWidget</b></a> ( QSqlField * field ) const</div></li><li><div class=fn>void <a href="#installPropertyMap"><b>installPropertyMap</b></a> ( QSqlPropertyMap * pmap )</div></li><li><div class=fn>virtual void <a href="#setRecord"><b>setRecord</b></a> ( QSqlRecord * buf )</div></li></ul><h2>Public Slots</h2><ul><li><div class=fn>virtual void <a href="#readField"><b>readField</b></a> ( QWidget * widget )</div></li><li><div class=fn>virtual void <a href="#writeField"><b>writeField</b></a> ( QWidget * widget )</div></li><li><div class=fn>virtual void <a href="#readFields"><b>readFields</b></a> ()</div></li><li><div class=fn>virtual void <a href="#writeFields"><b>writeFields</b></a> ()</div></li><li><div class=fn>virtual void <a href="#clear"><b>clear</b></a> ()</div></li><li><div class=fn>virtual void <a href="#clearValues"><b>clearValues</b></a> ( bool nullify = FALSE )</div></li></ul><h2>Protected Members</h2><ul><li><div class=fn>virtual void <a href="#insert-2"><b>insert</b></a> ( QWidget * widget, QSqlField * field )</div></li><li><div class=fn>virtual void <a href="#remove"><b>remove</b></a> ( QWidget * widget )</div></li></ul><hr><a name="details"></a><h2>Detailed Description</h2>The QSqlForm class creates and manages data entry forms tied to SQLdatabases.<p> <p> Typical use of a QSqlForm consists of the following steps:<p> <ol><li>Create the widgets you want to appear in the form.<li>Create a cursor and navigate to the record to be edited.<li>Create the QSqlForm.<li>Set the form's record buffer to the cursor's update buffer.<li>Insert each widget and the field it is to edit into the form.<li>Use <a href="#readFields">readFields</a>() to update the editor widgets with values from the database's fields.<li>Display the form and let the user edit values etc.<li>Use <a href="#writeFields">writeFields</a>() to update the database's field values with the values in the editor widgets.</ol><p> Note that a QSqlForm does not access the database directly, butmost often via QSqlFields which are part of a <a href="qsqlcursor.html">QSqlCursor</a>. A<a href="qsqlcursor.html#insert">QSqlCursor::insert</a>(), <a href="qsqlcursor.html#update">QSqlCursor::update</a>() or <a href="qsqlcursor.html#del">QSqlCursor::del</a>() callis needed to actually write values to the database.<p> Some sample code to initialize a form successfully:<p> <pre> <a href="qlineedit.html">QLineEdit</a> myEditor( this ); QSqlForm myForm( this ); <a href="qsqlcursor.html">QSqlCursor</a> myCursor( "mytable" ); // Execute a query to make the cursor valid myCursor.<a href="qsqlcursor.html#select">select</a>(); // Move the cursor to a valid record (the first record) myCursor.<a href="qsqlquery.html#next">next</a>(); // Set the form's record pointer to the cursor's edit buffer (which // contains the current record's values) myForm.<a href="#setRecord">setRecord</a>( myCursor.<a href="qsqlcursor.html#primeUpdate">primeUpdate</a>() ); // Insert a field into the form that uses myEditor to edit the // field 'somefield' in 'mytable' myForm.<a href="#insert">insert</a>( &myEditor, "somefield" ); // Update myEditor with the value from the mapped database field myForm.<a href="#readFields">readFields</a>(); ... // Let the user edit the form ... // Update the database myForm.<a href="#writeFields">writeFields</a>(); // Update the cursor's edit buffer from the form myCursor.<a href="qsqlcursor.html#update">update</a>(); // Update the database from the cursor's buffer </pre> <p> If you want to use custom editors for displaying/editing datafields, you need to install a custom <a href="qsqlpropertymap.html">QSqlPropertyMap</a>. The formuses this object to get or set the value of a widget.<p> Note that <em>Qt Designer</em> provides a visual means of creatingdata-aware forms.<p> <p>See also <a href="#installPropertyMap">installPropertyMap</a>(), <a href="qsqlpropertymap.html">QSqlPropertyMap</a> and <a href="database.html">Database Classes</a>.<hr><h2>Member Function Documentation</h2><h3 class=fn><a name="QSqlForm"></a>QSqlForm::QSqlForm ( <a href="qobject.html">QObject</a> * parent = 0, const char * name = 0 )</h3>Constructs a QSqlForm with parent <em>parent</em> and name <em>name</em>.<h3 class=fn><a name="~QSqlForm"></a>QSqlForm::~QSqlForm ()</h3> Destroys the object and frees any allocated resources.<h3 class=fn>void <a name="clear"></a>QSqlForm::clear ()<tt> [virtual slot]</tt></h3>Removes every widget, and the fields they're mapped to, from the form.<h3 class=fn>void <a name="clearValues"></a>QSqlForm::clearValues ( bool nullify = FALSE )<tt> [virtual slot]</tt></h3>Clears the values in all the widgets, and the fields they are mappedto, in the form. If <em>nullify</em> is TRUE (the default is FALSE), eachfield is also set to null.<h3 class=fn>uint <a name="count"></a>QSqlForm::count () const</h3>Returns the number of widgets in the form.<h3 class=fn><a href="qwidget.html">QWidget</a> * <a name="fieldToWidget"></a>QSqlForm::fieldToWidget ( <a href="qsqlfield.html">QSqlField</a> * field ) const</h3>Returns the widget that field <em>field</em> is mapped to.<h3 class=fn>void <a name="insert"></a>QSqlForm::insert ( <a href="qwidget.html">QWidget</a> * widget, const <a href="qstring.html">QString</a> & field )<tt> [virtual]</tt></h3> Inserts a <em>widget</em>, and the name of the <em>field</em> it is to be mappedto, into the form. To actually associate inserted widgets with anedit buffer, use <a href="#setRecord">setRecord</a>().<p> <p>See also <a href="#setRecord">setRecord</a>().<p>Examples: <a href="sql.html#x2224">sql/overview/form1/main.cpp</a> and <a href="sql.html#x2230">sql/overview/form2/main.cpp</a>.<h3 class=fn>void <a name="insert-2"></a>QSqlForm::insert ( <a href="qwidget.html">QWidget</a> * widget, <a href="qsqlfield.html">QSqlField</a> * field )<tt> [virtual protected]</tt></h3>This is an overloaded member function, provided for convenience. It behaves essentially like the above function.<p> Inserts a <em>widget</em>, and the <em>field</em> it is to be mapped to, intothe form.<h3 class=fn>void <a name="installPropertyMap"></a>QSqlForm::installPropertyMap ( <a href="qsqlpropertymap.html">QSqlPropertyMap</a> * pmap )</h3> Installs a custom <a href="qsqlpropertymap.html">QSqlPropertyMap</a>. This is useful if you plan tocreate your own custom editor widgets.<p> QSqlForm takes ownership of <em>pmap</em>, and <em>pmap</em> is thereforedeleted when QSqlForm goes out of scope.<p> <p>See also <a href="qdatatable.html#installEditorFactory">QDataTable::installEditorFactory</a>().<p>Example: <a href="sql.html#x2236">sql/overview/custom1/main.cpp</a>.<h3 class=fn>void <a name="readField"></a>QSqlForm::readField ( <a href="qwidget.html">QWidget</a> * widget )<tt> [virtual slot]</tt></h3>Updates the widget <em>widget</em> with the value from the SQL field it ismapped to. Nothing happens if no SQL field is mapped to the <em>widget</em>.<h3 class=fn>void <a name="readFields"></a>QSqlForm::readFields ()<tt> [virtual slot]</tt></h3>Updates the widgets in the form with current values from the SQLfields they are mapped to.<p>Examples: <a href="sql.html#x2225">sql/overview/form1/main.cpp</a> and <a href="sql.html#x2231">sql/overview/form2/main.cpp</a>.<h3 class=fn>void <a name="remove"></a>QSqlForm::remove ( <a href="qwidget.html">QWidget</a> * widget )<tt> [virtual protected]</tt></h3>Removes a <em>widget</em>, and hence the field it's mapped to, from the form.<h3 class=fn>void <a name="remove-2"></a>QSqlForm::remove ( const <a href="qstring.html">QString</a> & field )<tt> [virtual]</tt></h3> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.<p> Removes <em>field</em> from the form.<h3 class=fn>void <a name="setRecord"></a>QSqlForm::setRecord ( <a href="qsqlrecord.html">QSqlRecord</a> * buf )<tt> [virtual]</tt></h3> Sets <em>buf</em> as the record buffer for the form. To force thedisplay of the data from <em>buf</em>, use <a href="#readFields">readFields</a>().<p> <p>See also <a href="#readFields">readFields</a>() and <a href="#writeFields">writeFields</a>().<p>Examples: <a href="sql.html#x2237">sql/overview/custom1/main.cpp</a>, <a href="sql.html#x2226">sql/overview/form1/main.cpp</a> and <a href="sql.html#x2232">sql/overview/form2/main.cpp</a>.<h3 class=fn><a href="qwidget.html">QWidget</a> * <a name="widget"></a>QSqlForm::widget ( uint i ) const</h3>Returns the <em>i</em>-th widget in the form. Useful for traversing the widgetsin the form.<h3 class=fn><a href="qsqlfield.html">QSqlField</a> * <a name="widgetToField"></a>QSqlForm::widgetToField ( <a href="qwidget.html">QWidget</a> * widget ) const</h3>Returns the SQL field that widget <em>widget</em> is mapped to.<h3 class=fn>void <a name="writeField"></a>QSqlForm::writeField ( <a href="qwidget.html">QWidget</a> * widget )<tt> [virtual slot]</tt></h3>Updates the SQL field with the value from the <em>widget</em> it is mapped to.Nothing happens if no SQL field is mapped to the <em>widget</em>.<h3 class=fn>void <a name="writeFields"></a>QSqlForm::writeFields ()<tt> [virtual slot]</tt></h3>Updates the SQL fields with values from the widgets they are mappedto. To actually update the database with the contents of the recordbuffer, use <a href="qsqlcursor.html#insert">QSqlCursor::insert</a>(), <a href="qsqlcursor.html#update">QSqlCursor::update</a>() or<a href="qsqlcursor.html#del">QSqlCursor::del</a>() as appropriate.<p>Example: <a href="sql.html#x2233">sql/overview/form2/main.cpp</a>.<!-- eof --><hr><p>This file is part of the <a href="index.html">Qt toolkit</a>.Copyright © 1995-2002<a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center><table width=100% cellspacing=0 border=0><tr><td>Copyright © 2002 <a href="http://www.trolltech.com">Trolltech</a><td><a href="http://www.trolltech.com/trademarks.html">Trademarks</a><td align=right><div align=right>Qt version 3.0.5</div></table></div></address></body></html>⌨️ 快捷键说明
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