与gtk3一起使用cairo [英] using cairo with gtk3

问题描述

我试图在gtk3中用cairo绘制散点图。首先，我在这里使用示例： http://zetcode.com/tutorials/cairographicstutorial/

I am trying to draw a scatterplot with cairo in gtk3. To start, I am using the examples here: http://zetcode.com/tutorials/cairographicstutorial/

它们成功地用gtk2编译，但是没有显示图像。它们不使用gtk3进行编译，但是会出现以下错误：

They compile with gtk2 successfully but display no image. They do not compile with gtk3 but give the following error:

example.c: In function ‘on_expose_event’:
example.c:17:31: error: ‘GtkWidget’ has no member named ‘window’

任何

btw如果有帮助，我正在使用ArchLinux进行编写。

btw I am using writing using ArchLinux for this if that helps.

推荐答案

Gtk3进行了很多更改。 GtkWidget 的一部分没有成员 window ，成员已移至 GtkWidgetPrivate 这是一个不透明的结构，因此您不能直接从 GtkWidget 访问成员。您将必须使用访问器功能，在这种情况下，您需要 GtkWidget 的窗口成员，则可以使用 gtk_widget_get_window ，但这可能无法修复您正在使用的代码示例。请注意， expose_event 信号已替换为 draw 信号，因此您将需要更新实际绘制的函数适当（我认为您的情况是 on_expose_event ）。请参阅此链接以查看列表切换到Gtk3所需的更改。您可以从Gtk3源代码中引用 gtk-demo 应用程序提供的源或 demos / gtk-demo 提供的源代码来获取示例代码。 。

关于在Gtk2中未显示的图像，如果您正在处理图像样本，请确保在源代码中提到的路径中可以使用该图像文件。

希望这会有所帮助！

There have been quite a few changes in Gtk3. There is no member window exposed as part of GtkWidget anymore, the members have been moved to GtkWidgetPrivate which is an opaque structure so you cannot access the members directly from GtkWidget. You will have to use accessor function, in this case where you need window member of GtkWidget you can use gtk_widget_get_window, but that may not fix the code sample with which you are working. Please note that the expose_event signal has been replaced with draw signal so you will need to update the function which is actually drawing appropriately (on_expose_event in your case I think). Please refer this link to see the list of changes needed to switch to Gtk3. You can refer source provided by gtk-demo application or demos/gtk-demo from Gtk3 source code to get sample code.
Regarding image not being shown in case of Gtk2, if you are working with image sample, please make sure that the image file is available in the path mentioned in the source.
Hope this helps!

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