我是Linux（Slackware 14.2）用户，需要在我的计算机上为工作项目安装 mono 。安装slackbuild之后，我从https://www.mono-project.com/docs/getting-started/mono-basics/运行了代码，效果很好，直到我尝试如下使用' System.Windows.Forms '
using System;
using System.Windows.Forms;
public class HelloWorld : Form
{
static public void Main ()
{
Application.Run (new HelloWorld ());
}
public HelloWorld ()
{
Text = "Hello Mono World";
}
}
编译并运行后，我得到：
$ mono hello.exe
Unhandled Exception:
System.TypeInitializationException: The type initializer for 'System.Windows.Forms.WindowsFormsSynchronizationContext' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.Windows.Forms.ThemeEngine' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.Windows.Forms.ThemeWin32Classic' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.Drawing.KnownColors' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.Drawing.GDIPlus' threw an exception. ---> System.DllNotFoundException: libgdiplus.so.0
at (wrapper managed-to-native) System.Drawing.GDIPlus:GdiplusStartup (ulong&,System.Drawing.GdiplusStartupInput&,System.Drawing.GdiplusStartupOutput&)
at System.Drawing.GDIPlus..cctor () [0x000ab] in <ac0a7ab7ad9c4534aa7b9d68ccc688c1>:0
--- End of inner exception stack trace ---
at System.Drawing.KnownColors..cctor () [0x0001a] in <ac0a7ab7ad9c4534aa7b9d68ccc688c1>:0
--- End of inner exception stack trace ---
at System.Drawing.Color.get_Black () [0x00000] in <ac0a7ab7ad9c4534aa7b9d68ccc688c1>:0
at System.Windows.Forms.ThemeWin32Classic..cctor () [0x00000] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
--- End of inner exception stack trace ---
at System.Windows.Forms.ThemeEngine..cctor () [0x0002f] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
--- End of inner exception stack trace ---
at System.Windows.Forms.SystemInformation.get_MenuAccessKeysUnderlined () [0x00000] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
at System.Windows.Forms.Control..ctor () [0x000e4] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control:.ctor ()
at System.Windows.Forms.WindowsFormsSynchronizationContext..cctor () [0x00000] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
--- End of inner exception stack trace ---
at System.Windows.Forms.Control..ctor () [0x00014] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
at System.Windows.Forms.ScrollableControl..ctor () [0x00000] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
at System.Windows.Forms.ContainerControl..ctor () [0x0000e] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
at System.Windows.Forms.Form..ctor () [0x00012] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
at HelloWorld..ctor () [0x00000] in <ebd84f70eef34e1bac9228a36ebc3550>:0
at (wrapper remoting-invoke-with-check) HelloWorld:.ctor ()
at HelloWorld.Main () [0x00001] in <ebd84f70eef34e1bac9228a36ebc3550>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: The type initializer for 'System.Windows.Forms.WindowsFormsSynchronizationContext' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.Windows.Forms.ThemeEngine' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.Windows.Forms.ThemeWin32Classic' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.Drawing.KnownColors' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.Drawing.GDIPlus' threw an exception. ---> System.DllNotFoundException: libgdiplus.so.0
at (wrapper managed-to-native) System.Drawing.GDIPlus:GdiplusStartup (ulong&,System.Drawing.GdiplusStartupInput&,System.Drawing.GdiplusStartupOutput&)
at System.Drawing.GDIPlus..cctor () [0x000ab] in <ac0a7ab7ad9c4534aa7b9d68ccc688c1>:0
--- End of inner exception stack trace ---
at System.Drawing.KnownColors..cctor () [0x0001a] in <ac0a7ab7ad9c4534aa7b9d68ccc688c1>:0
--- End of inner exception stack trace ---
at System.Drawing.Color.get_Black () [0x00000] in <ac0a7ab7ad9c4534aa7b9d68ccc688c1>:0
at System.Windows.Forms.ThemeWin32Classic..cctor () [0x00000] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
--- End of inner exception stack trace ---
at System.Windows.Forms.ThemeEngine..cctor () [0x0002f] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
--- End of inner exception stack trace ---
at System.Windows.Forms.SystemInformation.get_MenuAccessKeysUnderlined () [0x00000] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
at System.Windows.Forms.Control..ctor () [0x000e4] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control:.ctor ()
at System.Windows.Forms.WindowsFormsSynchronizationContext..cctor () [0x00000] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
--- End of inner exception stack trace ---
at System.Windows.Forms.Control..ctor () [0x00014] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
at System.Windows.Forms.ScrollableControl..ctor () [0x00000] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
at System.Windows.Forms.ContainerControl..ctor () [0x0000e] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
at System.Windows.Forms.Form..ctor () [0x00012] in <cfc91f7a5a0243dda6f0da9f9f2bd749>:0
at HelloWorld..ctor () [0x00000] in <ebd84f70eef34e1bac9228a36ebc3550>:0
at (wrapper remoting-invoke-with-check) HelloWorld:.ctor ()
at HelloWorld.Main () [0x00001] in <ebd84f70eef34e1bac9228a36ebc3550>:0
我做错了（或没做过）吗？