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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"><HTML><HEAD><TITLE>文本输入构件 Text Entries</TITLE><METANAME="GENERATOR"CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+"><LINKREL="HOME"TITLE="GTK+ 2.0 教程"HREF="book1.html"><LINKREL="UP"TITLE="杂项构件"HREF="c816.html"><LINKREL="PREVIOUS"TITLE="状态栏 Statusbars"HREF="x982.html"><LINKREL="NEXT"TITLE="微调按钮 Spin Buttons"HREF="x1030.html"></HEAD><BODYCLASS="SECT1"BGCOLOR="#FFFFFF"TEXT="#000000"LINK="#0000FF"VLINK="#840084"ALINK="#0000FF"><DIVCLASS="NAVHEADER"><TABLESUMMARY="Header navigation table"WIDTH="100%"BORDER="0"CELLPADDING="0"CELLSPACING="0"><TR><THCOLSPAN="3"ALIGN="center">GTK+ 2.0 教程</TH></TR><TR><TDWIDTH="10%"ALIGN="left"VALIGN="bottom"><AHREF="x982.html"ACCESSKEY="P"><<< Previous</A></TD><TDWIDTH="80%"ALIGN="center"VALIGN="bottom">杂项构件</TD><TDWIDTH="10%"ALIGN="right"VALIGN="bottom"><AHREF="x1030.html"ACCESSKEY="N">Next >>></A></TD></TR></TABLE><HRALIGN="LEFT"WIDTH="100%"></DIV><DIVCLASS="SECT1"><H1CLASS="SECT1"><ANAME="SEC-TEXTENTRIES">文本输入构件 Text Entries</H1><P>文本输入构件(Entry widget)允许在一个单行文本框里输入和显示一行文本。文本可以用函数进行操作，如将新的文本替换、前插、追加到文本输入构件的当前内容中。</P><P>用下面的函数创建一个文本输入构件：</P><TABLEBORDER="0"BGCOLOR="#E0E0E0"WIDTH="100%"><TR><TD><PRECLASS="PROGRAMLISTING">GtkWidget *gtk_entry_new( void );</PRE></TD></TR></TABLE><P>下面的函数改变文本输入构件当前的文本内容。</P><TABLEBORDER="0"BGCOLOR="#E0E0E0"WIDTH="100%"><TR><TD><PRECLASS="PROGRAMLISTING">void gtk_entry_set_text( GtkEntry *entry, const gchar *text );</PRE></TD></TR></TABLE><P>gtk_entry_set_text() 函数用新的内容(contents)取代文本输入构件当前的内容。你可以注意到文本输入构件的类(class Entry)体现了可编辑的接口(Editable interface)(是的,gobject提供了类似Java的接口),它包含更多的函数来操作内容。</P><P>文本输入构件的内容可以用下面的函数获取。这在下面介绍的回调函数中是很有用的。</P><TABLEBORDER="0"BGCOLOR="#E0E0E0"WIDTH="100%"><TR><TD><PRECLASS="PROGRAMLISTING">const gchar *gtk_entry_get_text( GtkEntry *entry );</PRE></TD></TR></TABLE><P>这个函数返回的值在其内部被使用，不要用free()或g_free()释放它。</P><P>如果我们不想用户通过输入文字改变文本输入构件的内容，我们可以改变它的可编辑状态。</P><TABLEBORDER="0"BGCOLOR="#E0E0E0"WIDTH="100%"><TR><TD><PRECLASS="PROGRAMLISTING">void gtk_editable_set_editable( GtkEditable *entry, gboolean editable );</PRE></TD></TR></TABLE><P>上面的函数可以让我们通过传递一个TRUE或 FALSE 值作为<TTCLASS="LITERAL">editable</TT>参数来改变文本输入构件的可编辑状态。</P><P>如果想让文本输入构件输入的文本不回显(比如用于接收口令)，可以使用下面的函数，它也是取一个布尔值作为参数</P><TABLEBORDER="0"BGCOLOR="#E0E0E0"WIDTH="100%"><TR><TD><PRECLASS="PROGRAMLISTING">void gtk_entry_set_visibility( GtkEntry *entry, gboolean visible );</PRE></TD></TR></TABLE><P>文本你的某一部分可以用下面的函数设置为被选中。这个常在为文本输入构件设置了一个缺省值时使用，以方便用户删除它。</P><TABLEBORDER="0"BGCOLOR="#E0E0E0"WIDTH="100%"><TR><TD><PRECLASS="PROGRAMLISTING">void gtk_editable_select_region( GtkEditable *entry, gint start, gint end );</PRE></TD></TR></TABLE><P>如果我们想在用户输入文本时进行响应，可以为<TTCLASS="LITERAL">activate</TT>或<TTCLASS="LITERAL">changed</TT>信号设置回调函数。当用户在文本输入构件内部按回车键时引发Activate信号；在每次文本输入构件的文本发生变化时引发Changed信号，比如，每输入或删除一个字符。</P><P>下面的代码是一个使用文本输入构件的示例。</P><P><SPANCLASS="INLINEMEDIAOBJECT"><IMGSRC="images/entry.png"></SPAN></P><TABLEBORDER="0"BGCOLOR="#E0E0E0"WIDTH="100%"><TR><TD><PRECLASS="PROGRAMLISTING"> #include <stdio.h>#include <stdlib.h>#include <gtk/gtk.h>void enter_callback( GtkWidget *widget, GtkWidget *entry ){ const gchar *entry_text; entry_text = gtk_entry_get_text (GTK_ENTRY (entry)); printf("Entry contents: %s\n", entry_text);}void entry_toggle_editable( GtkWidget *checkbutton, GtkWidget *entry ){ gtk_editable_set_editable (GTK_EDITABLE (entry), GTK_TOGGLE_BUTTON (checkbutton)->active);}void entry_toggle_visibility( GtkWidget *checkbutton, GtkWidget *entry ){ gtk_entry_set_visibility (GTK_ENTRY (entry), GTK_TOGGLE_BUTTON (checkbutton)->active);}int main( int argc, char *argv[] ){ GtkWidget *window; GtkWidget *vbox, *hbox; GtkWidget *entry; GtkWidget *button; GtkWidget *check; gint tmp_pos; gtk_init (&argc, &argv); /* 创建一个新窗口 */ window = gtk_window_new (GTK_WINDOW_TOPLEVEL); gtk_widget_set_size_request (GTK_WIDGET (window), 200, 100); gtk_window_set_title (GTK_WINDOW (window), "GTK Entry"); g_signal_connect (G_OBJECT (window), "destroy", G_CALLBACK (gtk_main_quit), NULL); g_signal_connect_swapped (G_OBJECT (window), "delete_event", G_CALLBACK (gtk_widget_destroy), window); vbox = gtk_vbox_new (FALSE, 0); gtk_container_add (GTK_CONTAINER (window), vbox); gtk_widget_show (vbox); entry = gtk_entry_new (); gtk_entry_set_max_length (GTK_ENTRY (entry), 50); g_signal_connect (G_OBJECT (entry), "activate", G_CALLBACK (enter_callback), entry); gtk_entry_set_text (GTK_ENTRY (entry), "hello"); tmp_pos = GTK_ENTRY (entry)->text_length; gtk_editable_insert_text (GTK_EDITABLE (entry), " world", -1, &tmp_pos); gtk_editable_select_region (GTK_EDITABLE (entry), 0, GTK_ENTRY (entry)->text_length); gtk_box_pack_start (GTK_BOX (vbox), entry, TRUE, TRUE, 0); gtk_widget_show (entry); hbox = gtk_hbox_new (FALSE, 0); gtk_container_add (GTK_CONTAINER (vbox), hbox); gtk_widget_show (hbox); check = gtk_check_button_new_with_label ("Editable"); gtk_box_pack_start (GTK_BOX (hbox), check, TRUE, TRUE, 0); g_signal_connect (G_OBJECT (check), "toggled", G_CALLBACK (entry_toggle_editable), entry); gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (check), TRUE); gtk_widget_show (check); check = gtk_check_button_new_with_label ("Visible"); gtk_box_pack_start (GTK_BOX (hbox), check, TRUE, TRUE, 0); g_signal_connect (G_OBJECT (check), "toggled", G_CALLBACK (entry_toggle_visibility), entry); gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (check), TRUE); gtk_widget_show (check); button = gtk_button_new_from_stock (GTK_STOCK_CLOSE); g_signal_connect_swapped (G_OBJECT (button), "clicked", G_CALLBACK (gtk_widget_destroy), window); gtk_box_pack_start (GTK_BOX (vbox), button, TRUE, TRUE, 0); GTK_WIDGET_SET_FLAGS (button, GTK_CAN_DEFAULT); gtk_widget_grab_default (button); gtk_widget_show (button); gtk_widget_show (window); gtk_main(); return 0;}</PRE></TD></TR></TABLE></DIV><DIVCLASS="NAVFOOTER"><HRALIGN="LEFT"WIDTH="100%"><TABLESUMMARY="Footer navigation table"WIDTH="100%"BORDER="0"CELLPADDING="0"CELLSPACING="0"><TR><TDWIDTH="33%"ALIGN="left"VALIGN="top"><AHREF="x982.html"ACCESSKEY="P"><<< Previous</A></TD><TDWIDTH="34%"ALIGN="center"VALIGN="top"><AHREF="book1.html"ACCESSKEY="H">Home</A></TD><TDWIDTH="33%"ALIGN="right"VALIGN="top"><AHREF="x1030.html"ACCESSKEY="N">Next >>></A></TD></TR><TR><TDWIDTH="33%"ALIGN="left"VALIGN="top">状态栏 Statusbars</TD><TDWIDTH="34%"ALIGN="center"VALIGN="top"><AHREF="c816.html"ACCESSKEY="U">Up</A></TD><TDWIDTH="33%"ALIGN="right"VALIGN="top">微调按钮 Spin Buttons</TD></TR></TABLE></DIV></BODY></HTML>⌨️ 快捷键说明
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