在Gtktreeview中用C显示Mysql结果

Question

我尝试使用GtktreeView在C中显示mysql查询的结果，其中包含以下代码，该代码从gtkentry的更改处理程序中调用，以获得“输入时搜索”效果：

...
    result = mysql_store_result(conn);
if (result)
{
    while ((row = mysql_fetch_row(result)))
    {
    gtk_list_store_append(store, &iter);
    gtk_list_store_set(store, &iter, cID, row[0],
                                     cCity, row[1],
                                     cState, row[2],
                                     cPop, atoi(row[3]),
                                     cLast, "", -1);
   }
}
etc...

问题是，结果可能包含几千行数据，虽然mysql足够快，但这些数据量使GtkTreeView变得不可接受地慢(比打字慢得多，经常让计算机震惊)。当我在查询中输入LIMIT 20时，这段代码可以正常工作，但随后只能获得匹配数据的前20行。我认为这太慢了，因为gtktreeview的所有重绘都是活动的。在一些工具包中，可以在列表加载时关闭所有刷新，然后在加载完成时简单地显示结果。这样的事情在GtkTreeView中是可能的吗？

或者我能做点别的吗？比如把这个函数放在线程中？或任何其他解决方案？

感谢你对我的建议！

Answer 1

我不太清楚你的要求是什么。不幸的是，我之前也没有使用mysql的经验。但是考虑到结合使用GtkEntryCompletion和GtkEntry来实现“边输入边搜索”的效果，您必须创建一个GtkEntryCompletion并将其设置为GtkEntry。然后，您可以将模型设置为条目完成，从中选取完成数据。以下是基于gtk-demo源代码和coding.debuntu.org代码的示例代码：

#include <gtk/gtk.h>
#include <string.h>

static gboolean
on_match_select(GtkEntryCompletion *widget, GtkTreeModel *model,GtkTreeIter *iter, gpointer user_data)
{
    GValue value = {0, };
    GValue id = {0, };
    gtk_tree_model_get_value(model, iter, 1, &value);
    gtk_tree_model_get_value(model, iter, 0, &id);
    fprintf(stdout, "You have selected value=\"%s\" with id = %d\n",
        g_value_get_string(&value),
        g_value_get_int(&id));
    g_value_unset(&value);
    g_value_unset(&id);

    return FALSE;
}

/* Creates a tree model containing the completions */
static GtkTreeModel *
create_completion_model (void)
{
    GtkListStore *store;
    GtkTreeIter iter;
    int id = 0;
    char buffer[1024]={0,};

    store = gtk_list_store_new (2, G_TYPE_INT, G_TYPE_STRING);

    /* Here we add the data to be shown for completion */
    /* Add 10000 strings */
    for(id = 0; id < 10000; id++)
    {
        if(id%2)
            snprintf(buffer, sizeof buffer -1, "homer #%d with %d", id/2, id);
        else
            snprintf(buffer, sizeof buffer -1, "marge #%d with %d", id/2, id);

        gtk_list_store_append (store, &iter);
        gtk_list_store_set (store, &iter, 0, id, 1, buffer, -1);
    }
    return GTK_TREE_MODEL (store);
}


int main (void)
{
    GtkWidget *window;
    GtkWidget *vbox;
    GtkWidget *label;
    GtkWidget *entry;
    GtkEntryCompletion *completion;
    GtkTreeModel *completion_model;

    gtk_init (NULL, NULL);
    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(window),"Sample entry completion");
    g_signal_connect (window, "destroy", G_CALLBACK(gtk_main_quit), NULL);

    vbox = gtk_vbox_new (FALSE, 5);
    gtk_container_set_border_width (GTK_CONTAINER (window), 5);
    gtk_container_add(GTK_CONTAINER(window), vbox);

    label = gtk_label_new (NULL);
    gtk_label_set_markup (GTK_LABEL (label),
                        "Completion demo, try writing <b>homer/marge #...</b>; replace ... by a number b/w 0 &amp; 9999.");

    gtk_box_pack_start (GTK_BOX (vbox), label, FALSE, FALSE, 0);

    /* Create our entry */
    entry = gtk_entry_new ();
    gtk_box_pack_start (GTK_BOX (vbox), entry, FALSE, FALSE, 0);

    /* Create the completion object */
    completion = gtk_entry_completion_new ();

    /* Assign the completion to the entry */
    gtk_entry_set_completion (GTK_ENTRY (entry), completion);
    g_object_unref (completion);

    /* Create a tree model and use it as the completion model */
    completion_model = create_completion_model ();
    gtk_entry_completion_set_model (completion, completion_model);
    /* Connect callback for match selection */
    g_signal_connect(G_OBJECT (completion), "match-selected", G_CALLBACK (on_match_select), NULL);
    g_object_unref (completion_model);

    /* Use model column 1 (i.e. 2nd column) as the text column */
    /* Model currently used has int (id) in 1st column & string (data) in 2nd column */
    gtk_entry_completion_set_text_column (completion, 1);

    gtk_widget_show_all (window);
    gtk_main();

    return 0;
}

希望这比你当前的方法快一点。

希望这能有所帮助！