I'm tryng to port a winforms app created in Visual Studio to Mac with monodevelop. After resolving compiling errors, when I run the program, the application outputs these exceptions:
System.NullReferenceException: Object reference not set to an instance of an object
at System.Windows.Forms.TextBoxBase.set_Lines (System.String[] value) [0x00000] in <filename unknown>:0
at (wrapper remoting-invoke-with-check) System.Windows.Forms.TextBoxBase:set_Lines (string[])
at WindowsFormsApplication1.Main_Form.amp_portante_ValueChanged (System.Object Sender) [0x00025] in /Users/giuseppe/Desktop/CRUZER/Csound Converter/WindowsFormsApplication1/Main_Form.cs:381
at KnobControl.KnobControl.OnValueChanged (System.Object sender) [0x00000] in <filename unknown>:0
at KnobControl.KnobControl.set_Value (Int32 value) [0x00000] in <filename unknown>:0
at (wrapper remoting-invoke-with-check) KnobControl.KnobControl:set_Value (int)
at WindowsFormsApplication1.Main_Form.textb2_TextChanged (System.Object sender, System.EventArgs e) [0x00085] in /Users/giuseppe/Desktop/CRUZER/Csound Converter/WindowsFormsApplication1/Main_Form.cs:1023
at System.Windows.Forms.Control.OnTextChanged (System.EventArgs e) [0x00000] in <filename unknown>:0
at System.Windows.Forms.TextBoxBase.OnTextChanged (System.EventArgs e) [0x00000] in <filename unknown>:0
at System.Windows.Forms.TextBoxBase.set_Text (System.String value) [0x00000] in <filename unknown>:0
at System.Windows.Forms.TextBox.set_Text (System.String value) [0x00000] in <filename unknown>:0
at WindowsFormsApplication1.Main_Form.SimpleFM_Conf () [0x00058] in /Users/giuseppe/Desktop/CRUZER/Csound Converter/WindowsFormsApplication1/Main_Form.cs:45
at WindowsFormsApplication1.Main_Form.Main_Form_Load (System.Object sender, System.EventArgs e) [0x00012] in /Users/giuseppe/Desktop/CRUZER/Csound Converter/WindowsFormsApplication1/Main_Form.cs:359
at System.Windows.Forms.Form.OnLoad (System.EventArgs e) [0x00000] in <filename unknown>:0
at System.Windows.Forms.Form.OnLoadInternal (System.EventArgs e) [0x00000] in <filename unknown>:0
The application works perfectly in Visual Studio and I have no idea what I should do.
You probably have a custom control (KnobControl) which you can't instantiate.
Maybe you don't have this control or this control doesn't compile with mono.
Take a look at line 381 in Main_Form.cs
Regards,
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