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READEME.md

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+GTK 练习代码 (MAC 系统)
+
+<h2>安装<h2>
+- 输入命令 `brew install gtk+3`
+- 查看安装结果 `pkg-config --list-all | grep gtk`, 出现下面结果，说明安装成功
+  ```shell
+    gtk+-3.0                            GTK+ - GTK+ Graphical UI Library
+    gtk+-unix-print-3.0                 GTK+ - GTK+ Unix print support
+    gtk+-quartz-3.0                     GTK+ - GTK+ Graphical UI Library
+```