How to Negotiate Capability with Different Capability Container Types

Topics included in this article that describe how to negotiate capability with different capability container types are:

  • Setting Capability with TWON_ONEVALUE
  • Setting Capability with TWON_ARRAY
  • Setting Capability with TWON_ENUMERATION
  • Setting Capability with TWON_RANGE
  • Reading Value(s) through Capability Negotiation

    •  

    Setting Capability with TWON_ONEVALUE

    TWON_ONEVALUE capability container type can be used to set or return a single value (item) of a capability.

    To set a capability with TWON_ONEVALUE container, the following steps are needed:

  • Call OpenSource() to bring Dynamic .NET TWAIN to the state for capability negotiation;
  • Set the Capability property to the capability to be negotiated;
  • Set the CapType property to TWON_ONEVALUE;
  • If the data type of the capability is String, set the value of CapValueString property. For any other data types, set the value of CapValue property;
  • Call CapSet() to actually set the value.
    •

        

    C# Sample: 
    	Twain.OpenSource();
		
	Twain.Capability = Dynamsoft.DotNet.TWAIN.Enums.TWCapability.ICAP_UNITS;
	Twain.CapType = Dynamsoft.DotNet.TWAIN.Enums.TWCapType.TWON_ONEVALUE;
	Twain.CapValue = (double)Dynamsoft.DotNet.TWAIN.Enums.TWICapUNits.TWUN_INCHES;  // TWUN_INCHES
	
	if (Twain.CapSet())
		MessageBox.Show("Successful.");
	else
		MessageBox.Show("Failed.\r\n" + Twain.ErrorString);

     

     

    Setting Capability with TWON_ARRAY

    TWON_ARRAY capability container type can be used to set or return a group of associated individual values.

    To set a capabilIty with TWON_ARRAY  container, the following steps are needed:

  • Call OpenSource() to bring Dynamic .NET TWAIN to the state for capability negotiation;
  • Set the Capability property to the capability to be negotiated;
  • Set the CapType property to TWON_ARRAY;
  • Set the CapNumItems property to indicate how many items are in the array;
  • If the data type of the capability is String, use the CapItemsString() method to set the values. For any other data types, use the SetCapItems() method to set the values;
  • Call href="../html/M_Dynamsoft_DotNet_TWAIN_DynamicDotNetTwain_CapSet.htm">CapSet() to actually set the value.
    •

       

    C# Sample:  
    	Twain.OpenSource();
	Twain.Capability = Dynamsoft.DotNet.TWAIN.Enums.TWCapability.ICAP_FILTER;
	Twain.CapType = Dynamsoft.DotNet.TWAIN.Enums.TWCapType.TWON_ARRAY;
	Twain.CapNumItems = 3;    //Set cap values count.
    

	// Set the cap's values
	Twain.SetCapItems(0, (double)Dynamsoft.DotNet.TWAIN.Enums.TWICapFilterType.TWFT_NONE);
	Twain.SetCapItems(1, (double)Dynamsoft.DotNet.TWAIN.Enums.TWICapFilterType.TWFT_GREEN);
	Twain.SetCapItems(2, (double)Dynamsoft.DotNet.TWAIN.Enums.TWICapFilterType.TWFT_BLUE);
	if (Twain.CapSet())
		MessageBox.Show("Successful.");
	else
		MessageBox.Show("Failed.\r\n" + Twain.ErrorString);

          

     

    Setting Capability with TWON_ENUMERATION

    TWON_ENUMERATION capability container type can be used to set or return a group of associated individual values describing a capability. The values are ordered from the lowest to highest values, but the step size between every two values is probably not uniform.

    To set a capability with TWON_ENUMERATION  container, the following steps are needed:

  • Call OpenSource() to bring Dynamic .NET TWAIN to the state for capability negotiation;
  • Set the Capability property to the capability to be negotiated;
  • Set the CapType property to TWON_ENUMERATION;
  • Set the CapNumItems property to indicate how many items are in the array;
  • If the data type of the capability is String, use the SetCapItemsString() method to set the values. For any other data types, use the SetCapItems() method to set the values;
  • Set the CapCurrentIndex to indicate the index of the current value;
  • Call CapSet() to actually set the value.
    •

       

    C# Sample: 
    	Twain.OpenSource();
	Twain.Capability = Dynamsoft.DotNet.TWAIN.Enums.TWCapability.ICAP_XRESOLUTION;
	Twain.CapType = Dynamsoft.DotNet.TWAIN.Enums.TWCapType.TWON_ENUMERATION;
	Twain.CapNumItems = 3;    //Set the cap values count.
    

	// Set the cap's values
	Twain.SetCapItems(0, 80);
	Twain.SetCapItems(1, 100);
	Twain.SetCapItems(2, 120);
	Twain.CapCurrentIndex = 2;    //Set the cap's current value's index in the ENEMERATION.
	
	if (Twain.CapSet())
		MessageBox.Show("Successful.");
	else
		MessageBox.Show("Failed.\r\n" + Twain.ErrorString);
     

     

    Setting Capability with TWON_RANGE

    TW_RANGE capability container type can be used to set or return a range of individual values describing a capability. The values are uniformly distributed between a minimum and a maximum value. The step size between every two values is constant.

    To set a capability with TW_RANGE  container, the following steps are needed:

  • Call OpenSource() to bring Dynamic .NET TWAIN to the state for capability negotiation;
  • Set the Capability property to the capability to be negotiated;
  • Set the CapType property to TW_RANGE;
  • Set the CapMinValue, CapMaxValue, CapStepSize and CapCurrentValue properties;
  • Call CapSet() to actually set the value.
    •

       

    C# Sample: 
    	Twain.OpenSource();
	Twain.Capability = Dynamsoft.DotNet.TWAIN.Enums.TWCapability.ICAP_XRESOLUTION;
	Twain.CapType = Dynamsoft.DotNet.TWAIN.Enums.TWCapType.TWON_RANGE;
    

	// Set the cap's values
	Twain.CapMinValue = 80;
	Twain.CapMaxValue = 200;
	Twain.CapStepSize = 20;
	Twain.CapCurrentValue = 120;
	
	if (Twain.CapSet())
		MessageBox.Show("Successful.");
	else
		MessageBox.Show("Failed.\r\n" + Twain.ErrorString);
     

     

    Reading Value(s) from Capability Negotiation

    To read values from a capability:

  • Call OpenSource() to bring Dynamic .NET TWAIN to the state for capability negotiation;
  • Set the Capability property to the capability to be negotiated;
  • Call CapGet() to get the data;
  • Get the data according to the returned capability container type.
    •

     

    C# Sample: 
    	Twain.OpenSource();
	
	Twain.Capability = Dynamsoft.DotNet.TWAIN.Enums.TWCapability.CAP_xxx;
	
	if (!Twain.CapGet())
	{
		MessageBox.Show("Failed.\r\n" + Twain.ErrorString);
		return;
	}
	
	string txtCap;
	
	if (Twain.CapType == Dynamsoft.DotNet.TWAIN.Enums.TWCapType.TWON_ONEVALUE)
	{                
		txtCap = "Container type is TWON_ONEVALUE\r\n";
		txtCap = txtCap + "Current Value:" + Twain.CapValue + "\r\n";
	}
	else if (Twain.CapType == Dynamsoft.DotNet.TWAIN.Enums.TWCapType.TWON_ARRAY)
	{
		txtCap = "Container type is TWON_ARRAY"+ "\r\n";
		txtCap = txtCap + "Available Values:";
	
		for (int lngIndex = 0; lngIndex < Twain.CapNumItems; lngIndex ++)
		{
			if (lngIndex < Twain.CapNumItems - 1)
				txtCap = txtCap + Twain.GetCapItems(lngIndex) + ",";
			else
				txtCap = txtCap + Twain.GetCapItems(lngIndex);
		}
	}
	else if (Twain.CapType == Dynamsoft.DotNet.TWAIN.Enums.TWCapType.TWON_ENUMERATION)
	{
		txtCap = "Container type is TWON_ENUMERATION" + "\r\n";
		txtCap = txtCap + "Current Value:" + Twain.GetCapItems(Twain.CapCurrentIndex)+ "\r\n";
		txtCap = txtCap + "Default Value:" + Twain.GetCapItems(Twain.CapDefaultIndex)+ "\r\n";
		txtCap = txtCap + "Available Values:";
	
		for (int lngIndex = 0; lngIndex < Twain.CapNumItems; lngIndex ++)
		{
			if (lngIndex < Twain.CapNumItems - 1)
				txtCap = txtCap + Twain.GetCapItems(lngIndex) + ",";
			else
				txtCap = txtCap + Twain.GetCapItems(lngIndex);
		}
	}
	else if (Twain.CapType == Dynamsoft.DotNet.TWAIN.Enums.TWCapType.TWON_RANGE)
	{
		txtCap = "Container type is TWON_RANGE"+ "\r\n";
		txtCap = txtCap + "Current Value:" + Twain.CapCurrentValue+ "\r\n";
		txtCap = txtCap + "Default Value:" + Twain.CapDefaultValue+ "\r\n";
		txtCap = txtCap + "Min Value:" + Twain.CapMinValue+ "\r\n";
		txtCap = txtCap + "Max Value:" + Twain.CapMaxValue+ "\r\n";
		txtCap = txtCap + "Step Size:" + Twain.CapStepSize;
	}

     

    See Also

    Capability Container Types