Question

我希望你做得很好。

正如标题中所提到的，我的问题是：如何使用C语言将SQLite数据库中的数据显示到GTK + 3.0 TreeView中？

我有两个问题要做：

1）如何使用Glade 3正确设计TreeView，让它看起来像桌子？

2）如何将从SQLite接收的数据显示到TreeView中。

提前谢谢。

Answer 1

在没有代码的情况下，我将展示一个虚拟数据的小例子：

#include <sqlite3.h>
#include <gtk/gtk.h>
#include <stdio.h>


int callback(void *, int, char **, char **);


enum {
  LIST_ID,
  LIST_BRAND,
  LIST_PRICE,
  N_COLUMNS
};


int main(int argc, char** argv) {
   GtkCellRenderer *renderer;
   GtkTreeViewColumn *column;
   GtkListStore *store; 
   GtkWidget *window;
   GtkWidget *list;

   GtkWidget *vbox;
   GtkWidget *label;
   GtkTreeSelection *selection;

   gtk_init(&argc, &argv);


   // THIS IS THE MODEL: 3 Columns of Type String

   store = gtk_list_store_new(N_COLUMNS, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING);

   // CREATE A SQLITE FILE WITH TABLE CARS AND POPULATE WITH DATA

   sqlite3 *db;
   char *err_msg = 0;

   int rc = sqlite3_open("test.db", &db);

   if (rc != SQLITE_OK) {

       fprintf(stderr, "Cannot open database: %s\n", 
               sqlite3_errmsg(db));
       sqlite3_close(db);

       return 1;
   }

   char *sql = "DROP TABLE IF EXISTS Cars;" 
                "CREATE TABLE Cars(Id INT, Name TEXT, Price INT);" 
                "INSERT INTO Cars VALUES(1, 'Audi', 52642);" 
                "INSERT INTO Cars VALUES(2, 'Mercedes', 57127);" 
                "INSERT INTO Cars VALUES(3, 'Skoda', 9000);" 
                "INSERT INTO Cars VALUES(4, 'Volvo', 29000);" 
                "INSERT INTO Cars VALUES(5, 'Bentley', 350000);" 
                "INSERT INTO Cars VALUES(6, 'Citroen', 21000);" 
                "INSERT INTO Cars VALUES(7, 'Hummer', 41400);" 
                "INSERT INTO Cars VALUES(8, 'Volkswagen', 21600);";

    rc = sqlite3_exec(db, sql, 0, 0, &err_msg);

   sql = "SELECT * FROM Cars";

   rc = sqlite3_exec(db, sql, callback, store, &err_msg);

   if (rc != SQLITE_OK ) {

      fprintf(stderr, "Failed to select data\n");
      fprintf(stderr, "SQL error: %s\n", err_msg);

      sqlite3_free(err_msg);
      sqlite3_close(db);

      return 1;
   } 

   sqlite3_close(db);

   window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
   list = gtk_tree_view_new();

   // CREATE 3 COLUMNS WITH TEXT CELL RENDERERS

   renderer = gtk_cell_renderer_text_new ();
   column = gtk_tree_view_column_new_with_attributes("ID",
          renderer, "text", LIST_ID, NULL);
   gtk_tree_view_append_column(GTK_TREE_VIEW(list), column);

   renderer = gtk_cell_renderer_text_new ();
   column = gtk_tree_view_column_new_with_attributes("BRAND",
          renderer, "text", LIST_BRAND, NULL);
   gtk_tree_view_append_column(GTK_TREE_VIEW(list), column);

   renderer = gtk_cell_renderer_text_new ();
   column = gtk_tree_view_column_new_with_attributes("PRICE",
          renderer, "text", LIST_PRICE, NULL);
   gtk_tree_view_append_column(GTK_TREE_VIEW(list), column);


   // SET THE TREE VIEW MODEL 
   gtk_tree_view_set_model(GTK_TREE_VIEW(list), GTK_TREE_MODEL(store));

   // TREEVIEW WILL KEEP A REFERENCE SO DECREASE REFCOUNT
   g_object_unref(store);

   // SETUP THE UI
   gtk_window_set_title(GTK_WINDOW(window), "List view");
   gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
   gtk_container_set_border_width(GTK_CONTAINER(window), 10);
   gtk_window_set_default_size(GTK_WINDOW(window), 270, 250);

   gtk_tree_view_set_headers_visible(GTK_TREE_VIEW(list), FALSE);

   vbox = gtk_vbox_new(FALSE, 0);

   gtk_box_pack_start(GTK_BOX(vbox), list, TRUE, TRUE, 5);

   label = gtk_label_new("");
   gtk_box_pack_start(GTK_BOX(vbox), label, FALSE, FALSE, 5);

   gtk_container_add(GTK_CONTAINER(window), vbox);

   g_signal_connect(G_OBJECT (window), "destroy",
      G_CALLBACK(gtk_main_quit), NULL);

   gtk_widget_show_all(window);

   gtk_main();

   return 0;
}

int callback(void *model, int argc, char **argv, char **azColName) {
   GtkTreeIter iter;

   for (int i = 0; i < argc; i++) {

      printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");

   }

   printf("\n");

   // AFTER PRINTING TO CONSOLE FILL THE MODEL WITH THE DATA

   gtk_list_store_append (GTK_LIST_STORE(model), &iter);
   gtk_list_store_set (GTK_LIST_STORE(model), &iter, LIST_ID, argv[0],
         LIST_BRAND, argv[1],
         LIST_PRICE, argv[2],
         -1);

   return 0;
}

此示例不使用GLADE，因为在尝试设置单元格渲染器时存在错误。可以创建树视图和列，但单元格渲染器必须以编程方式完成。

最重要的部分是sqlite3回调，它将GtkTreeModel / GtkListStore作为第一个参数，然后填充数据，也称为填充。

然后将模型设置为树视图模型，树视图将显示查询数据。

希望它有所帮助。

PS：编译：

cc -o sqlview sqlview.c -lsqlite3 `pkg-config --cflags --libs gtk+-3.0`

结果：

如何将SQLite数据库中的数据显示到GTK TreeView中？

1 个答案: