GTK+，基于 C 的软件，图像损坏
GTK+, C-based software, corruption with Images
我正在为家用 CNC 铣床的 digital-read-out/controller 编写一些代码，目标是带有 TFT/LCD 的 Pi，我选择使用 C，我知道，和 GTK+3，我知道的比较少（在黑暗中摸索，突然想到）。
控制器的一个页面（通过主 application/GTK 计时器事件的更新调用来安排，具体取决于活动页面）应该显示 3 个（或其他）按钮，并带有按钮的视觉指示器状态。按钮图像从 .png 文件加载。
创建时，我加载 selected/de-selected 图像并存储在每个按钮的结构中。刷新时，我更改 selected/de-selected 图像的状态并使用适当的图像更新按钮图像。或者这就是理论。在初始化时，我将图像默认为 de-selected。我可以很容易地更改为 selected，但随后调用 deselected 图像会导致出现 GTK 错误消息。
函数 play_init() 被调用以创建页面内容（前缀“play...” - 这将是一个模板 'page' 来测试不同的 GTK 方法 - 这是为了在不破坏主代码库的情况下以不同的方式解决同样的问题。
每个 'page' 创建一个 main() 附加到 GTK notebook 的容器，因此此启动代码不用担心 window 设置 - 那在别处。
在下面的代码部分，我进行了相当多的修改，并添加了调试代码以默认为 de-selected，然后更改为 selected，返回 de-selected 等等，都带有“我在这里”调试语句。这是为了避免指针超出范围等任何问题，以试图了解我哪里出错了。我 知道 它与设置按钮图像有关，但无法弄清楚我在这里错过了什么。确实，图像 selection 应该在包含的事件框事件处理程序中进行管理...但是在此处转储调试代码有助于将事情放在一起。
所有调试文本（1、2、3、4、5 等）只是为了让我可以找到代码开始失败的地方。我最近添加了 gtk_button_set_image(.., NULL) 以尝试在设置新图像之前“卸载”图像。 Nada，没有变化。
/****************************************************
* Local type definitions
****************************************************/
enum buttons {START, PAUSE, STOP};
typedef enum buttons button_t;
struct play_eb_buttons
{
GtkWidget *button; // Button holding the button image
GtkWidget *im_selc; // "Selected" image
GtkWidget *im_deselc; // "De-selected" image
GtkWidget *eb; // Event box containing button
GtkWidget *parent; // Points to the parent of the event box
bool selc; // New selection state
bool last_selc; // Previous selection state
};
typedef struct play_eb_buttons play_eb_button_t;
/****************************************************
* Code Implementation ** INTERNALS **
****************************************************/
void playSetSelcState(play_eb_button_t *button, bool selc_state)
{
button->selc = selc_state;
if ((button->selc == true ) && (button->last_selc == false ))
{
printf("Setting image (selc) 0x%llX\n", button->im_selc);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_selc);
}
else if ((button->selc == false ) && (button->last_selc == true))
{
printf("Setting image (deselc) 0x%llX\n", button->im_deselc);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_deselc);
}
button->last_selc = button->selc;
}
gint playgreen_press_callback( GtkWidget *widget, GdkEvent *event, gpointer callback_data )
{
printf("Green callback invoked\n");
playSetSelcState(&play_eb_button[START], true);
playSetSelcState(&play_eb_button[PAUSE], false);
playSetSelcState(&play_eb_button[STOP], false);
return TRUE;
}
gint playyellow_press_callback( GtkWidget *widget, GdkEvent *event, gpointer callback_data )
{
printf("Yellow callback invoked\n");
playSetSelcState(&play_eb_button[START], false);
playSetSelcState(&play_eb_button[PAUSE], true);
playSetSelcState(&play_eb_button[STOP], false);
return TRUE;
}
gint playred_press_callback( GtkWidget *widget, GdkEvent *event, gpointer callback_data )
{
printf("Red callback invoked\n");
playSetSelcState(&play_eb_button[START], false);
playSetSelcState(&play_eb_button[PAUSE], false);
playSetSelcState(&play_eb_button[STOP], true);
return TRUE;
}
void playCreateButton( GtkWidget *parent, char *selc, char *deselc, char *name, int col, int row, GCallback func, play_eb_button_t *button )
{
GtkWidget *label;
button->button = gtk_button_new();
button->eb = gtk_event_box_new();
button->parent = parent;
button->selc = false;
button->last_selc = false;
button->im_selc = gtk_image_new_from_file(selc);
button->im_deselc = gtk_image_new_from_file(deselc);
gtk_widget_set_vexpand(button->im_selc, TRUE);
gtk_widget_set_vexpand(button->im_deselc, TRUE);
printf("1\n");
gtk_button_set_image(GTK_BUTTON(button->button), NULL);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_deselc);
printf("2\n");
gtk_button_set_image(GTK_BUTTON(button->button), NULL);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_selc);
printf("3\n");
gtk_button_set_image(GTK_BUTTON(button->button), NULL);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_deselc);
printf("4\n");
gtk_button_set_image(GTK_BUTTON(button->button), NULL);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_selc);
printf("5\n");
gtk_button_set_image(GTK_BUTTON(button->button), NULL);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_deselc);
printf("6\n");
gtk_button_set_image(GTK_BUTTON(button->button), NULL);
gtk_container_add(GTK_CONTAINER(button->eb), button->button);
gtk_grid_attach(GTK_GRID(parent), button->eb, col,row, 1, 1);
g_signal_connect (button->eb, "button_press_event", G_CALLBACK (func), NULL);
// eb = gtk_event_box_new();
// label = gtk_label_new(name);
// gtk_container_add(GTK_CONTAINER(eb), label);
// gtk_widget_set_name(label, "buttons");
// gtk_grid_attach(GTK_GRID(parent), eb, col+1, row, 1, 1);
// g_signal_connect (eb, "button_press_event", G_CALLBACK (func), NULL);
printf("'%s' at 0x%16llX and 0x%16llX\n", name, button->im_selc, button->im_deselc);
}
/****************************************************
* Code Implementation ** EXTERNALS **
****************************************************/
/*
* play_init()
*
* Setup for the complete DRO page for the GUI
*/
void play_init()
{
GtkWidget *grid;
play_container = gtk_event_box_new();
grid = gtk_grid_new();
gtk_container_add(GTK_CONTAINER(play_container), grid);
gtk_widget_modify_bg(grid, GTK_STATE_NORMAL, &colour_black);
playCreateButton(grid, "push-button-green.png" ,"push-button-green-dselc.png", "Run!", 0, 1, (GCallback)playgreen_press_callback, &play_eb_button[START]);
playCreateButton(grid, "push-button-yellow.png","push-button-yellow-dselc.png", "Pause", 0, 2, (GCallback)playyellow_press_callback, &play_eb_button[PAUSE]);
playCreateButton(grid, "push-button-red.png" ,"push-button-red-dselc.png", "STOP", 0, 3, (GCallback)playred_press_callback, &play_eb_button[STOP]);
playSetSelcState(&play_eb_button[START], true);
playSetSelcState(&play_eb_button[START], false);
}
我机器的输出（主机：HP Z600，运行ning Ubuntu 20.04）
Hostname = 'mike-HP-Z600-Workstation'
Initialising
State = Connecting
1
2
3
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.182: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
4
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.182: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
5
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.182: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
6
'Run!' at 0x 56446A49E2B0 and 0x 56446A49E420
1
2
3
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.185: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
4
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.185: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
5
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.185: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
6
'Pause' at 0x 56446A49E700 and 0x 56446A49E870
1
2
3
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.187: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
4
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.187: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
5
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.187: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
6
'STOP' at 0x 56446A49E870 and 0x 56446A49E2B0
Setting image (selc) 0x56446A49E2B0
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.187: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (deselc) 0x56446A49E420
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.188: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (selc) 0x56446A49E2B0
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:26.806: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Graphics terminated
Closing
我已经通过这个尝试了 GDB 并观察到 eb_button 数组预期损坏或其他东西，但该结构保持良好。错误消息表明图像在调用“3”之前受到影响（图像指针保持非空）
如果我让事件处理程序代码 运行 我可以得到其他 GTK 错误，所有围绕相同的调用结构来设置按钮图像...
(SiegDROsGtk3:556962): Gtk-CRITICAL **: 19:48:22.637: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (selc) 0x558A215F72B0
(SiegDROsGtk3:556962): Gtk-CRITICAL **: 19:48:25.225: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (deselc) 0x558A215F7420
Setting image (selc) 0x558A215F72B0
(SiegDROsGtk3:556962): Gtk-CRITICAL **: 19:48:30.341: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (deselc) 0x558A215F7420
(SiegDROsGtk3:556962): GLib-GObject-CRITICAL **: 19:48:32.898: g_object_ref: assertion 'G_IS_OBJECT (object)' failed
(SiegDROsGtk3:556962): Gtk-CRITICAL **: 19:48:32.898: gtk_widget_get_parent: assertion 'GTK_IS_WIDGET (widget)' failed
Setting image (selc) 0x558A215F72B0
(SiegDROsGtk3:556962): Gtk-CRITICAL **: 19:48:35.458: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (deselc) 0x558A215F7420
(SiegDROsGtk3:556962): Gtk-CRITICAL **: 19:48:38.022: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (selc) 0x558A215F72B0
运行 这个没有初始化调试的东西，按钮都是 de-selected，我可以 select 例如绿色，并以正确选择的图像突出显示；选择例如黄色按钮绿色没有 de-select （得到那个错误），黄色成功 selects。按 Reg 和黄色不会 deselect （得到错误）但红色会。在某些时候，我要么完全丢失按钮图像，要么有时会得到一个未加载图像的默认图像。
看起来连续调用 gtk_button_set_image 正在破坏预加载的图像。
显然我在做一些愚蠢的事情，但我找不到一个明智的 google 来判断我做错了什么。
求助？！
那是因为引用计数。详细描述可以在下面找到 here，简短版本。
所有的GObject都以rc(reference count, refcount)设置为1开始，但是所有的widgets都是GInitiallyUnowned（它们有特殊的flag，表明它还没有一个owner）
当您第一次将小部件打包到容器中时 g_object_ref_sink 被调用，它会取得小部件的所有权，将 rc 设置为 1 并删除标志。因此，当您用新图像替换图像时，将取消引用先前的图像。当取消引用时，它的 rc 降为 0，对象自动销毁。
您可以通过将任何对象转换为 (GObject*) 并查看它的 ref_count 字段来检查 GDB 中的此行为。
可以做什么：
- 手动参考图像。如果您调用
_ref_sink，您将获得对象所有权。当它被添加到容器中时，它将被引用（rc 将为 2）并在移除时取消引用（rc 将为 1，因此对象将仍然存在）。您还需要在程序结束时取消引用图像。
- 存储图标名称而不是小部件并在
playSetSelcState 中创建新图像
我正在为家用 CNC 铣床的 digital-read-out/controller 编写一些代码，目标是带有 TFT/LCD 的 Pi，我选择使用 C，我知道，和 GTK+3，我知道的比较少（在黑暗中摸索，突然想到）。
控制器的一个页面（通过主 application/GTK 计时器事件的更新调用来安排，具体取决于活动页面）应该显示 3 个（或其他）按钮，并带有按钮的视觉指示器状态。按钮图像从 .png 文件加载。
创建时，我加载 selected/de-selected 图像并存储在每个按钮的结构中。刷新时，我更改 selected/de-selected 图像的状态并使用适当的图像更新按钮图像。或者这就是理论。在初始化时，我将图像默认为 de-selected。我可以很容易地更改为 selected，但随后调用 deselected 图像会导致出现 GTK 错误消息。
函数 play_init() 被调用以创建页面内容（前缀“play...” - 这将是一个模板 'page' 来测试不同的 GTK 方法 - 这是为了在不破坏主代码库的情况下以不同的方式解决同样的问题。
每个 'page' 创建一个 main() 附加到 GTK notebook 的容器，因此此启动代码不用担心 window 设置 - 那在别处。
在下面的代码部分，我进行了相当多的修改，并添加了调试代码以默认为 de-selected，然后更改为 selected，返回 de-selected 等等，都带有“我在这里”调试语句。这是为了避免指针超出范围等任何问题，以试图了解我哪里出错了。我 知道 它与设置按钮图像有关，但无法弄清楚我在这里错过了什么。确实，图像 selection 应该在包含的事件框事件处理程序中进行管理...但是在此处转储调试代码有助于将事情放在一起。
所有调试文本（1、2、3、4、5 等）只是为了让我可以找到代码开始失败的地方。我最近添加了 gtk_button_set_image(.., NULL) 以尝试在设置新图像之前“卸载”图像。 Nada，没有变化。
/****************************************************
* Local type definitions
****************************************************/
enum buttons {START, PAUSE, STOP};
typedef enum buttons button_t;
struct play_eb_buttons
{
GtkWidget *button; // Button holding the button image
GtkWidget *im_selc; // "Selected" image
GtkWidget *im_deselc; // "De-selected" image
GtkWidget *eb; // Event box containing button
GtkWidget *parent; // Points to the parent of the event box
bool selc; // New selection state
bool last_selc; // Previous selection state
};
typedef struct play_eb_buttons play_eb_button_t;
/****************************************************
* Code Implementation ** INTERNALS **
****************************************************/
void playSetSelcState(play_eb_button_t *button, bool selc_state)
{
button->selc = selc_state;
if ((button->selc == true ) && (button->last_selc == false ))
{
printf("Setting image (selc) 0x%llX\n", button->im_selc);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_selc);
}
else if ((button->selc == false ) && (button->last_selc == true))
{
printf("Setting image (deselc) 0x%llX\n", button->im_deselc);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_deselc);
}
button->last_selc = button->selc;
}
gint playgreen_press_callback( GtkWidget *widget, GdkEvent *event, gpointer callback_data )
{
printf("Green callback invoked\n");
playSetSelcState(&play_eb_button[START], true);
playSetSelcState(&play_eb_button[PAUSE], false);
playSetSelcState(&play_eb_button[STOP], false);
return TRUE;
}
gint playyellow_press_callback( GtkWidget *widget, GdkEvent *event, gpointer callback_data )
{
printf("Yellow callback invoked\n");
playSetSelcState(&play_eb_button[START], false);
playSetSelcState(&play_eb_button[PAUSE], true);
playSetSelcState(&play_eb_button[STOP], false);
return TRUE;
}
gint playred_press_callback( GtkWidget *widget, GdkEvent *event, gpointer callback_data )
{
printf("Red callback invoked\n");
playSetSelcState(&play_eb_button[START], false);
playSetSelcState(&play_eb_button[PAUSE], false);
playSetSelcState(&play_eb_button[STOP], true);
return TRUE;
}
void playCreateButton( GtkWidget *parent, char *selc, char *deselc, char *name, int col, int row, GCallback func, play_eb_button_t *button )
{
GtkWidget *label;
button->button = gtk_button_new();
button->eb = gtk_event_box_new();
button->parent = parent;
button->selc = false;
button->last_selc = false;
button->im_selc = gtk_image_new_from_file(selc);
button->im_deselc = gtk_image_new_from_file(deselc);
gtk_widget_set_vexpand(button->im_selc, TRUE);
gtk_widget_set_vexpand(button->im_deselc, TRUE);
printf("1\n");
gtk_button_set_image(GTK_BUTTON(button->button), NULL);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_deselc);
printf("2\n");
gtk_button_set_image(GTK_BUTTON(button->button), NULL);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_selc);
printf("3\n");
gtk_button_set_image(GTK_BUTTON(button->button), NULL);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_deselc);
printf("4\n");
gtk_button_set_image(GTK_BUTTON(button->button), NULL);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_selc);
printf("5\n");
gtk_button_set_image(GTK_BUTTON(button->button), NULL);
gtk_button_set_image(GTK_BUTTON(button->button), button->im_deselc);
printf("6\n");
gtk_button_set_image(GTK_BUTTON(button->button), NULL);
gtk_container_add(GTK_CONTAINER(button->eb), button->button);
gtk_grid_attach(GTK_GRID(parent), button->eb, col,row, 1, 1);
g_signal_connect (button->eb, "button_press_event", G_CALLBACK (func), NULL);
// eb = gtk_event_box_new();
// label = gtk_label_new(name);
// gtk_container_add(GTK_CONTAINER(eb), label);
// gtk_widget_set_name(label, "buttons");
// gtk_grid_attach(GTK_GRID(parent), eb, col+1, row, 1, 1);
// g_signal_connect (eb, "button_press_event", G_CALLBACK (func), NULL);
printf("'%s' at 0x%16llX and 0x%16llX\n", name, button->im_selc, button->im_deselc);
}
/****************************************************
* Code Implementation ** EXTERNALS **
****************************************************/
/*
* play_init()
*
* Setup for the complete DRO page for the GUI
*/
void play_init()
{
GtkWidget *grid;
play_container = gtk_event_box_new();
grid = gtk_grid_new();
gtk_container_add(GTK_CONTAINER(play_container), grid);
gtk_widget_modify_bg(grid, GTK_STATE_NORMAL, &colour_black);
playCreateButton(grid, "push-button-green.png" ,"push-button-green-dselc.png", "Run!", 0, 1, (GCallback)playgreen_press_callback, &play_eb_button[START]);
playCreateButton(grid, "push-button-yellow.png","push-button-yellow-dselc.png", "Pause", 0, 2, (GCallback)playyellow_press_callback, &play_eb_button[PAUSE]);
playCreateButton(grid, "push-button-red.png" ,"push-button-red-dselc.png", "STOP", 0, 3, (GCallback)playred_press_callback, &play_eb_button[STOP]);
playSetSelcState(&play_eb_button[START], true);
playSetSelcState(&play_eb_button[START], false);
}
我机器的输出（主机：HP Z600，运行ning Ubuntu 20.04）
Hostname = 'mike-HP-Z600-Workstation'
Initialising
State = Connecting
1
2
3
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.182: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
4
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.182: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
5
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.182: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
6
'Run!' at 0x 56446A49E2B0 and 0x 56446A49E420
1
2
3
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.185: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
4
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.185: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
5
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.185: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
6
'Pause' at 0x 56446A49E700 and 0x 56446A49E870
1
2
3
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.187: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
4
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.187: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
5
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.187: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
6
'STOP' at 0x 56446A49E870 and 0x 56446A49E2B0
Setting image (selc) 0x56446A49E2B0
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.187: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (deselc) 0x56446A49E420
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:24.188: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (selc) 0x56446A49E2B0
(SiegDROsGtk3:556896): Gtk-CRITICAL **: 19:42:26.806: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Graphics terminated
Closing
我已经通过这个尝试了 GDB 并观察到 eb_button 数组预期损坏或其他东西，但该结构保持良好。错误消息表明图像在调用“3”之前受到影响（图像指针保持非空）
如果我让事件处理程序代码 运行 我可以得到其他 GTK 错误，所有围绕相同的调用结构来设置按钮图像...
(SiegDROsGtk3:556962): Gtk-CRITICAL **: 19:48:22.637: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (selc) 0x558A215F72B0
(SiegDROsGtk3:556962): Gtk-CRITICAL **: 19:48:25.225: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (deselc) 0x558A215F7420
Setting image (selc) 0x558A215F72B0
(SiegDROsGtk3:556962): Gtk-CRITICAL **: 19:48:30.341: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (deselc) 0x558A215F7420
(SiegDROsGtk3:556962): GLib-GObject-CRITICAL **: 19:48:32.898: g_object_ref: assertion 'G_IS_OBJECT (object)' failed
(SiegDROsGtk3:556962): Gtk-CRITICAL **: 19:48:32.898: gtk_widget_get_parent: assertion 'GTK_IS_WIDGET (widget)' failed
Setting image (selc) 0x558A215F72B0
(SiegDROsGtk3:556962): Gtk-CRITICAL **: 19:48:35.458: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (deselc) 0x558A215F7420
(SiegDROsGtk3:556962): Gtk-CRITICAL **: 19:48:38.022: gtk_button_set_image: assertion 'image == NULL || GTK_IS_WIDGET (image)' failed
Setting image (selc) 0x558A215F72B0
运行 这个没有初始化调试的东西，按钮都是 de-selected，我可以 select 例如绿色，并以正确选择的图像突出显示；选择例如黄色按钮绿色没有 de-select （得到那个错误），黄色成功 selects。按 Reg 和黄色不会 deselect （得到错误）但红色会。在某些时候，我要么完全丢失按钮图像，要么有时会得到一个未加载图像的默认图像。
看起来连续调用 gtk_button_set_image 正在破坏预加载的图像。
显然我在做一些愚蠢的事情，但我找不到一个明智的 google 来判断我做错了什么。
求助？！
那是因为引用计数。详细描述可以在下面找到 here，简短版本。
所有的GObject都以rc(reference count, refcount)设置为1开始，但是所有的widgets都是GInitiallyUnowned（它们有特殊的flag，表明它还没有一个owner）
当您第一次将小部件打包到容器中时 g_object_ref_sink 被调用，它会取得小部件的所有权，将 rc 设置为 1 并删除标志。因此，当您用新图像替换图像时，将取消引用先前的图像。当取消引用时，它的 rc 降为 0，对象自动销毁。
您可以通过将任何对象转换为 (GObject*) 并查看它的 ref_count 字段来检查 GDB 中的此行为。
可以做什么：
- 手动参考图像。如果您调用
_ref_sink，您将获得对象所有权。当它被添加到容器中时，它将被引用（rc 将为 2）并在移除时取消引用（rc 将为 1，因此对象将仍然存在）。您还需要在程序结束时取消引用图像。 - 存储图标名称而不是小部件并在
playSetSelcState 中创建新图像