刷新容器中的子项 - GTK [英] Refresh child-items in a container - GTK
问题描述
我正在用图形用户界面开发某种金融计算器。我正在使用gtk-lib，我遇到了一个无法解决的问题。它关于如何动态更新（刷新）窗口及其子项 - 更具体地说 - 容器中有一个子项是文本标签。我希望根据在textinputfield中输入的内容来更改此标签。
我习惯于使用java来轻松调用名为invalidate（）的方法。 c中是否有类似的解决方案？或者是一个解决方案，删除这个chidlitem，并添加一个新的？
提前致谢
#include< gtk / gtk.h>
static GtkWidget * txt;
static GtkWidget * window;
static GtkWidget * vbox，* assetPrice，* strikePrice;
static GtkWidget * asset_label;
static GtkWidget * frame;
static void entry_Submit（GtkWidget * widget，GtkWidget * entry）
{
const gchar * text = gtk_entry_get_text（GTK_ENTRY（txt））;
printf（Result：％s\\\
，text）;
$ b static void CreateTextBox（GtkWidget ** entry，GtkWidget * vbox）
{
* entry = gtk_entry_new（）;
gtk_entry_set_text（GTK_ENTRY（* entry），）;
gtk_box_pack_start（GTK_BOX（vbox），* entry，TRUE，TRUE，0）;
}
int main（int argc，char * argv []）
{
GtkWidget * button;
gtk_init（& argc，& argv）;
window = gtk_window_new（GTK_WINDOW_TOPLEVEL）;
gtk_widget_set_size_request（GTK_WIDGET（window），300，300）;
gtk_window_set_title（GTK_WINDOW（window），金融计算器）;
g_signal_connect（window，destroy，G_CALLBACK（gtk_main_quit），NULL）;
g_signal_connect_swapped（窗口，delete-event，G_CALLBACK（gtk_widget_destroy），窗口）;
vbox = gtk_vbox_new（FALSE，0）;
gtk_container_add（GTK_CONTAINER（window），vbox）;
gtk_widget_show（vbox）;
frame = gtk_frame_new（ASSET PRICE）;
asset_label = gtk_label_new（股票价格，stockmarketindex ...）;
gtk_container_add（GTK_CONTAINER（frame），asset_label）;
gtk_box_pack_start（GTK_BOX（vbox），frame，FALSE，FALSE，0）;
assetPrice = gtk_hbox_new（FALSE，0）;
gtk_container_add（GTK_CONTAINER（vbox），assetPrice）;
gtk_widget_show（assetPrice）;
frame = gtk_frame_new（RESULT：）;
asset_label = gtk_label_new（... new value）;
gtk_container_add（GTK_CONTAINER（frame），asset_label）;
gtk_box_pack_start（GTK_BOX（vbox），frame，FALSE，FALSE，0）;
CreateTextBox（& txt，assetPrice）;
button = gtk_button_new_with_label（Calculate）;
g_signal_connect_swapped（button，clicked，G_CALLBACK（entry_Submit），window）;
gtk_box_pack_start（GTK_BOX（vbox），button，TRUE，TRUE，0）;
gtk_widget_set_can_default（button，TRUE）;
gtk_widget_grab_default（button）;
gtk_widget_show_all（window）;
gtk_main（）;
$ b $ / code>
对preedit-changed和/或改变和/或 激活信号。然后通过 gtk_label_set_text（yourlabel，gtk_entry_get_text（yourentry））; 设置您的标签文本，如果您想直接复制/粘贴它。
注意：
$ b $ gtk_entry_get_text（yourentry）给你一个指向内部存储的指针，所以不要直接修改它，使用 g_strdup 并对副本进行操作。在上面它是好的（afaik），因为 gtk_label_set_text 会反正复制文本。 （另外不要忘记释放你的东西）
请参阅 https://developer.gnome.org/gtk3/3.4/GtkEntry.html 和 https://developer.gnome.org/gtk3/3.4/GtkLabel.html 以获取详细信息。
I am developing some kind of financial calculator in c with a graphical userinterface. I am using the gtk-lib and I have encountered one problem that right that could not be solved. Its about how to dynamically update (refresh) the window and its childs - more specifically - there is one child item in the container that is a text-label. I want this label to be changed according to what is entered in the textinputfield.
I am used to java where one easily can call a method named invalidate(). Is there a similar solution in c? Or is a solution to delete this chidlitem and and add a new one?
Thanks in advance
#include <gtk/gtk.h>
static GtkWidget *txt;
static GtkWidget *window;
static GtkWidget *vbox, *assetPrice, *strikePrice;
static GtkWidget *asset_label;
static GtkWidget *frame;
static void entry_Submit(GtkWidget *widget, GtkWidget *entry)
{
const gchar *text = gtk_entry_get_text(GTK_ENTRY (txt));
printf ("Result: %s\n", text);
}
static void CreateTextBox(GtkWidget **entry, GtkWidget *vbox)
{
*entry = gtk_entry_new();
gtk_entry_set_text (GTK_ENTRY (*entry), "");
gtk_box_pack_start (GTK_BOX (vbox), *entry, TRUE, TRUE, 0);
}
int main(int argc, char *argv[] )
{
GtkWidget *button;
gtk_init (&argc, &argv);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_widget_set_size_request (GTK_WIDGET (window), 300, 300);
gtk_window_set_title (GTK_WINDOW (window), "FINANCIAL CALCULATOR");
g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
g_signal_connect_swapped (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);
frame = gtk_frame_new ("ASSET PRICE");
asset_label = gtk_label_new ("stock price, stockmarketindex ...");
gtk_container_add (GTK_CONTAINER (frame), asset_label);
gtk_box_pack_start (GTK_BOX (vbox), frame, FALSE, FALSE, 0);
assetPrice = gtk_hbox_new (FALSE, 0);
gtk_container_add (GTK_CONTAINER (vbox), assetPrice);
gtk_widget_show(assetPrice);
frame = gtk_frame_new ("RESULT: ");
asset_label = gtk_label_new ("... new value");
gtk_container_add (GTK_CONTAINER (frame), asset_label);
gtk_box_pack_start (GTK_BOX (vbox), frame, FALSE, FALSE, 0);
CreateTextBox(&txt, assetPrice);
button = gtk_button_new_with_label("Calculate");
g_signal_connect_swapped (button, "clicked", G_CALLBACK (entry_Submit), window);
gtk_box_pack_start (GTK_BOX (vbox), button, TRUE, TRUE, 0);
gtk_widget_set_can_default (button, TRUE);
gtk_widget_grab_default (button);
gtk_widget_show_all (window);
gtk_main ();
}
Hook up a callbacke to the "preedit-changed" and/or "changed" and/or "activate" signal(s). Then set your label's text in the callback via gtk_label_set_text (yourlabel, gtk_entry_get_text (yourentry)); if you want to copy/paste it directly.
Note:
gtk_entry_get_text (yourentry) gives you a pointer to internal storage, so DO NOT modify it directly, use g_strdup and operate on a copy. In the above it is ok (afaik) as gtk_label_set_text will copy the text anyways. (Also don't forget to free your stuff you alocated.)
See https://developer.gnome.org/gtk3/3.4/GtkEntry.html and https://developer.gnome.org/gtk3/3.4/GtkLabel.html for details.
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