TreeViewImageIndexConverter.cs source code in C# .NET

                        Code:
                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / WinForms / Managed / System / WinForms / TreeViewImageIndexConverter.cs / 1 / TreeViewImageIndexConverter.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

/* 
 */ 

 
namespace System.Windows.Forms {

    using System.Collections;
    using System.ComponentModel; 
    using System.Diagnostics;
    using System.Globalization; 
    using System.Collections.Specialized; 

    ///  
    /// 
    ///      TreeViewImageIndexConverter is a class that can be used to convert
    ///      image index values one data type to another.
    ///  
    public class TreeViewImageIndexConverter : ImageIndexConverter {
 
        ///  
        protected override bool IncludeNoneAsStandardValue {
            get { 
                return false;
            }
        }
 
        /// 
        ///  
        ///     
        ///       Converts the given value object to a 32-bit signed integer object.
        ///     
        /// 
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value) {

            string strValue = value as string; 
            if (strValue != null) {
 
               if (String.Compare(strValue, SR.GetString(SR.toStringDefault), true, culture) == 0) { 
                   return -1;
               } 
               else if (String.Compare(strValue, SR.GetString(SR.toStringNone), true, culture) == 0) {
                   return -2;
               }
            } 
 	    return base.ConvertFrom(context, culture, value);
        } 
 

        ///  
        /// 
        ///      Converts the given object to another type.  The most common types to convert
        ///      are to and from a string object.  The default implementation will make a call
        ///      to ToString on the object if the object is valid and if the destination 
        ///      type is string.  If this cannot convert to the desitnation type, this will
        ///      throw a NotSupportedException. 
        ///  
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) {
            if (destinationType == null) { 
                throw new ArgumentNullException("destinationType");
            }

 
            if (destinationType == typeof(string) && value is int) {
                int intValue = (int)value; 
                if (intValue == -1) { 
                    return SR.GetString(SR.toStringDefault);
                } 
                else if (intValue == -2) {
                    return SR.GetString(SR.toStringNone);
                }
            } 

            return base.ConvertTo(context, culture, value, destinationType); 
        } 

        ///  
        /// 
        ///      Retrieves a collection containing a set of standard values
        ///      for the data type this validator is designed for.  This
        ///      will return null if the data type does not support a 
        ///      standard set of values.
        ///  
        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context) { 
            if (context != null && context.Instance != null) {
                object instance = context.Instance; 

                PropertyDescriptor imageListProp = ImageListUtils.GetImageListProperty(context.PropertyDescriptor, ref instance);

                while (instance != null && imageListProp == null) { 
                    PropertyDescriptorCollection props = TypeDescriptor.GetProperties(instance);
 
                    foreach (PropertyDescriptor prop in props) { 
                        if (typeof(ImageList).IsAssignableFrom(prop.PropertyType)) {
                            imageListProp = prop; 
                            break;
                        }
                    }
 
                    if (imageListProp == null) {
                        // We didn't find the image list in this component.  See if the 
                        // component has a "parent" property.  If so, walk the tree... 
                        //
                        PropertyDescriptor parentProp = props[ParentImageListProperty]; 
                        if (parentProp != null) {
                            instance = parentProp.GetValue(instance);
                        }
                        else { 
                            // Stick a fork in us, we're done.
                            // 
                            instance = null; 
                        }
                    } 
                }

                if (imageListProp != null) {
                    ImageList imageList = (ImageList)imageListProp.GetValue(instance); 

                    if (imageList != null) { 
                        // Create array to contain standard values 
                        //
                        object[] values; 
                        int nImages = imageList.Images.Count+2;
                        values = new object[nImages];
			values[nImages-2] = -1;
			values[nImages-1] = -2; 

                        // Fill in the array 
                        // 
                        for (int i = 0; i < nImages-2; i++) {
                            values[i] = i; 
                        }
                        return new StandardValuesCollection(values);
                    }
                } 
            }
 
            return new StandardValuesCollection(new object[] { -1, -2 }); 
        }
    } 
} // Namespace system.windows.forms


// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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TreeViewImageIndexConverter.cs source code in C# .NET

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