📄 inputverifier.html
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Frameset//EN""http://www.w3.org/TR/REC-html40/frameset.dtd"><!--NewPage--><HTML><HEAD><!-- Generated by javadoc on Thu Apr 27 23:38:24 PDT 2000 --><TITLE>Java 2 Platform SE v1.3: Class InputVerifier</TITLE><LINK REL ="stylesheet" TYPE="text/css" HREF="../../stylesheet.css" TITLE="Style"></HEAD><BODY BGCOLOR="white"><!-- ========== START OF NAVBAR ========== --><A NAME="navbar_top"><!-- --></A><TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0"><TR><TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"><A NAME="navbar_top_firstrow"><!-- --></A><TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3"> <TR ALIGN="center" VALIGN="top"> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD> <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="class-use/InputVerifier.html"><FONT CLASS="NavBarFont1"><B>Use</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../index-files/index-1.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD> </TR></TABLE></TD><TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM><b>Java<sup><font size=-2>TM</font></sup> 2 Platform<br>Std. Ed. v1.3</b></EM></TD></TR><TR><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../javax/swing/InputMap.html"><B>PREV CLASS</B></A> <A HREF="../../javax/swing/JApplet.html"><B>NEXT CLASS</B></A></FONT></TD><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../index.html" TARGET="_top"><B>FRAMES</B></A> <A HREF="InputVerifier.html" TARGET="_top"><B>NO FRAMES</B></A></FONT></TD></TR><TR><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> SUMMARY: INNER | FIELD | <A HREF="#constructor_summary">CONSTR</A> | <A HREF="#method_summary">METHOD</A></FONT></TD><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">DETAIL: FIELD | <A HREF="#constructor_detail">CONSTR</A> | <A HREF="#method_detail">METHOD</A></FONT></TD></TR></TABLE><!-- =========== END OF NAVBAR =========== --><HR><!-- ======== START OF CLASS DATA ======== --><H2><FONT SIZE="-1">javax.swing</FONT><BR>Class InputVerifier</H2><PRE><A HREF="../../java/lang/Object.html">java.lang.Object</A> | +--<B>javax.swing.InputVerifier</B></PRE><HR><DL><DT>public abstract class <B>InputVerifier</B><DT>extends <A HREF="../../java/lang/Object.html">Object</A></DL><P>The purpose of this class is to help clients support smooth focus navigation through GUIs with text fields. Such GUIs often need to ensure that the text entered by the user is valid (for example, that it's in the proper format) before allowing the user to navigate out of the text field. To do this, clients create a subclass of InputVerifier and, using JComponent's <code>setInputVerifier</code> method, attach an instance of their subclass to the JComponent whose input they want to validate. Before focus is transfered to another Swing component that requests it, the input verifier's <code>shouldYieldFocus</code> method is called. Focus is transfered only if that method returns <code>true</code>. <p> The following example has two text fields, with the first one expecting the string "pass" to be entered by the user. If that string is entered in the first text field, then the user can advance to the second text field either by clicking in it or by pressing TAB. However, if another string is entered in the first text field, then the user will be unable to transfer focus to the second text field. <p> <pre> import java.awt.*; import java.util.*; import java.awt.event.*; import javax.swing.*; // This program demonstrates the use of the Swing InputVerifier class. // It creates two text fields; the first of the text fields expects the // string "pass" as input, and will allow focus to advance out of it // only after that string is typed in by the user. class VerifierTest extends JFrame { public VerifierTest () { JTextField tf; tf = new JTextField ("TextField1"); getContentPane().add (tf, BorderLayout.NORTH); tf.setInputVerifier(new PassVerifier()); tf = new JTextField ("TextField2"); getContentPane().add (tf, BorderLayout.SOUTH); addWindowListener (new MyWAdapter ()); } public static void main (String [] args) { Frame f = new VerifierTest (); f.pack(); f.show(); } class MyWAdapter extends WindowAdapter { public void windowClosing(WindowEvent event) { System.exit (0); } } class PassVerifier extends InputVerifier { public boolean verify(JComponent input) { JTextField tf = (JTextField) input; String pass = tf.getText(); if (pass.equals("pass")) return true; else return false; } } } </pre><P><DL><DT><B>Since: </B><DD>1.3</DD></DL><HR><P><!-- ======== INNER CLASS SUMMARY ======== --><!-- =========== FIELD SUMMARY =========== --><!-- ======== CONSTRUCTOR SUMMARY ======== --><A NAME="constructor_summary"><!-- --></A><TABLE BORDER="1" CELLPADDING="3" CELLSPACING="0" WIDTH="100%"><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TD COLSPAN=2><FONT SIZE="+2"><B>Constructor Summary</B></FONT></TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD><CODE><B><A HREF="../../javax/swing/InputVerifier.html#InputVerifier()">InputVerifier</A></B>()</CODE><BR> </TD></TR></TABLE> <!-- ========== METHOD SUMMARY =========== --><A NAME="method_summary"><!-- --></A><TABLE BORDER="1" CELLPADDING="3" CELLSPACING="0" WIDTH="100%"><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TD COLSPAN=2><FONT SIZE="+2"><B>Method Summary</B></FONT></TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> boolean</CODE></FONT></TD><TD><CODE><B><A HREF="../../javax/swing/InputVerifier.html#shouldYieldFocus(javax.swing.JComponent)">shouldYieldFocus</A></B>(<A HREF="../../javax/swing/JComponent.html">JComponent</A> input)</CODE><BR> Calls <code>verify(input)</code> to ensure that the input is valid.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract boolean</CODE></FONT></TD><TD><CODE><B><A HREF="../../javax/swing/InputVerifier.html#verify(javax.swing.JComponent)">verify</A></B>(<A HREF="../../javax/swing/JComponent.html">JComponent</A> input)</CODE><BR> Checks whether the JComponent's input is valid.</TD></TR></TABLE> <A NAME="methods_inherited_from_class_java.lang.Object"><!-- --></A><TABLE BORDER="1" CELLPADDING="3" CELLSPACING="0" WIDTH="100%"><TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor"><TD><B>Methods inherited from class java.lang.<A HREF="../../java/lang/Object.html">Object</A></B></TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD><CODE><A HREF="../../java/lang/Object.html#clone()">clone</A>, <A HREF="../../java/lang/Object.html#equals(java.lang.Object)">equals</A>, <A HREF="../../java/lang/Object.html#finalize()">finalize</A>, <A HREF="../../java/lang/Object.html#getClass()">getClass</A>, <A HREF="../../java/lang/Object.html#hashCode()">hashCode</A>, <A HREF="../../java/lang/Object.html#notify()">notify</A>, <A HREF="../../java/lang/Object.html#notifyAll()">notifyAll</A>, <A HREF="../../java/lang/Object.html#toString()">toString</A>, <A HREF="../../java/lang/Object.html#wait()">wait</A>, <A HREF="../../java/lang/Object.html#wait(long)">wait</A>, <A HREF="../../java/lang/Object.html#wait(long, int)">wait</A></CODE></TD></TR></TABLE> <P><!-- ============ FIELD DETAIL =========== --><!-- ========= CONSTRUCTOR DETAIL ======== --><A NAME="constructor_detail"><!-- --></A><TABLE BORDER="1" CELLPADDING="3" CELLSPACING="0" WIDTH="100%"><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TD COLSPAN=1><FONT SIZE="+2"><B>Constructor Detail</B></FONT></TD></TR></TABLE><A NAME="InputVerifier()"><!-- --></A><H3>InputVerifier</H3><PRE>public <B>InputVerifier</B>()</PRE><DL></DL><!-- ============ METHOD DETAIL ========== --><A NAME="method_detail"><!-- --></A><TABLE BORDER="1" CELLPADDING="3" CELLSPACING="0" WIDTH="100%"><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TD COLSPAN=1><FONT SIZE="+2"><B>Method Detail</B></FONT></TD></TR></TABLE><A NAME="verify(javax.swing.JComponent)"><!-- --></A><H3>verify</H3><PRE>public abstract boolean <B>verify</B>(<A HREF="../../javax/swing/JComponent.html">JComponent</A> input)</PRE><DL><DD>Checks whether the JComponent's input is valid. This method should have no side effects. It returns a boolean indicating the status of the argument's input.<DD><DL><DT><B>Parameters:</B><DD><CODE>input</CODE> - the JComponent to verify<DT><B>Returns:</B><DD><code>true</code> when valid, <code>false</code> when invalid<DT><B>See Also: </B><DD><A HREF="../../javax/swing/JComponent.html#setInputVerifier(javax.swing.InputVerifier)"><CODE>JComponent.setInputVerifier(javax.swing.InputVerifier)</CODE></A>, <A HREF="../../javax/swing/JComponent.html#getInputVerifier()"><CODE>JComponent.getInputVerifier()</CODE></A></DL></DD></DL><HR><A NAME="shouldYieldFocus(javax.swing.JComponent)"><!-- --></A><H3>shouldYieldFocus</H3><PRE>public boolean <B>shouldYieldFocus</B>(<A HREF="../../javax/swing/JComponent.html">JComponent</A> input)</PRE><DL><DD>Calls <code>verify(input)</code> to ensure that the input is valid. This method can have side effects. In particular, this method is called when the user attempts to advance focus out of the argument component into another Swing component in this window. If this method returns <code>true</code>, then the focus is transfered normally; if it returns <code>false</code>, then the focus remains in the argument component.<DD><DL><DT><B>Parameters:</B><DD><CODE>input</CODE> - the JComponent to verify<DT><B>Returns:</B><DD><code>true</code> when valid, <code>false</code> when invalid<DT><B>See Also: </B><DD><A HREF="../../javax/swing/JComponent.html#setInputVerifier(javax.swing.InputVerifier)"><CODE>JComponent.setInputVerifier(javax.swing.InputVerifier)</CODE></A>, <A HREF="../../javax/swing/JComponent.html#getInputVerifier()"><CODE>JComponent.getInputVerifier()</CODE></A></DL></DD></DL><!-- ========= END OF CLASS DATA ========= --><HR><!-- ========== START OF NAVBAR ========== --><A NAME="navbar_bottom"><!-- --></A><TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0"><TR><TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"><A NAME="navbar_bottom_firstrow"><!-- --></A><TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3"> <TR ALIGN="center" VALIGN="top"> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD> <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="class-use/InputVerifier.html"><FONT CLASS="NavBarFont1"><B>Use</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../index-files/index-1.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD> </TR></TABLE></TD><TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM><b>Java<sup><font size=-2>TM</font></sup> 2 Platform<br>Std. Ed. v1.3</b></EM></TD></TR><TR><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../javax/swing/InputMap.html"><B>PREV CLASS</B></A> <A HREF="../../javax/swing/JApplet.html"><B>NEXT CLASS</B></A></FONT></TD><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../index.html" TARGET="_top"><B>FRAMES</B></A> <A HREF="InputVerifier.html" TARGET="_top"><B>NO FRAMES</B></A></FONT></TD></TR><TR><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> SUMMARY: INNER | FIELD | <A HREF="#constructor_summary">CONSTR</A> | <A HREF="#method_summary">METHOD</A></FONT></TD><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">DETAIL: FIELD | <A HREF="#constructor_detail">CONSTR</A> | <A HREF="#method_detail">METHOD</A></FONT></TD></TR></TABLE><!-- =========== END OF NAVBAR =========== --><HR><font size="-1"><a href="http://java.sun.com/cgi-bin/bugreport.cgi">Submit a bug or feature</a><br>For further API reference and developer documentation, see <a href="http://java.sun.com/products/jdk/1.3/devdocs-vs-specs.html">Java 2 SDK SE Developer Documentation</a>. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples. <p>Java, Java 2D, and JDBC are trademarks or registered trademarks of Sun Microsystems, Inc. in the US and other countries.<br>Copyright 1993-2000 Sun Microsystems, Inc. 901 San Antonio Road<br>Palo Alto, California, 94303, U.S.A. All Rights Reserved.</font></BODY></HTML>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -