I am writing an extended treeview, just with a few extra properties in my TreeNode class with designtime support.
The code is allmost ready, but at the moment I'm completely stuck with the following code. Everything I try at this point results in (another) exception...
Maybe anyone has an idea how to go futher? I don't know it anymore
using System; using System.ComponentModel; using System.ComponentModel.Design; using System.ComponentModel.Design.Serialization; using System.Drawing.Design; using System.Globalization; using System.Reflection; using System.Runtime.Serialization; using System.Windows.Forms;namespace MyProject.Forms { public class MenuTreeView : TreeView { public MenuTreeView() { // }
[Editor(typeof(MenuTreeNodeCollectionEditor), typeof(UITypeEditor))] //[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)] public new TreeNodeCollection Nodes { get { return base.Nodes; } } } [Serializable] [DefaultProperty("Text")] [TypeConverter(typeof(MenuTreeNodeConverter))] public class MenuTreeNode : TreeNode, ISerializable { private string description = ""; public MenuTreeNode() : base() { // } public MenuTreeNode(string text) : base(text) { // } public MenuTreeNode(string text, string description) : base(text) { this.description = description; } public MenuTreeNode(string text, MenuTreeNode[] children) : base(text, children) { // } public override object Clone() { object clone = base.Clone(); MenuTreeNode node = clone as MenuTreeNode; if (node != null) { node.Description = Description; return node; } else return clone; } void ISerializable.GetObjectData(SerializationInfo info, StreamingContext context) { Serialize(info, context); } protected override void Deserialize(SerializationInfo info, StreamingContext context) { Description = info.GetString("Description"); base.Deserialize(info, context); } protected override void Serialize(SerializationInfo info, StreamingContext context) { info.AddValue("Description", Description); base.Serialize(info, context); } [DefaultValue("")] public string Description { get { return description; } set { description = value; } } } public class MenuTreeNodeConverter : TypeConverter { public override bool CanConvertFrom(ITypeDescriptorContext context, Type type) { if (type == typeof(string)) { return true; } return base.CanConvertFrom(context, type); } public override bool CanConvertTo(ITypeDescriptorContext context, Type type) { if (type == typeof(InstanceDescriptor) || type == typeof(string)) { return true; } return base.CanConvertTo(context, type); } public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo info, object value) { if (value != null && value is string) { string[] items = ((string)value).Split(','); return new MenuTreeNode(items[0], items[1]); } return base.ConvertFrom(context, info, value); } public override object ConvertTo(ITypeDescriptorContext context, CultureInfo info, object value, Type type) { MenuTreeNode node = value as MenuTreeNode; if (value != null) { if (type == typeof(string)) { return node.Text + "," + node.Description; } else if (type == typeof(InstanceDescriptor)) { ConstructorInfo constructor = typeof(MenuTreeNode).GetConstructor(new Type[] { typeof(string), typeof(string) }); return new InstanceDescriptor(constructor, new object[] { node.Text, node.Description }, true); } } return base.ConvertTo(context, info, value, type); } } public class MenuTreeNodeCollectionEditor : CollectionEditor { public MenuTreeNodeCollectionEditor(Type t) : base(t) { // } protected override Type CreateCollectionItemType() { return typeof(MenuTreeNode); } protected override Type[] CreateNewItemTypes() { return new Type[] { typeof(MenuTreeNode) }; } protected override object CreateInstance(Type itemType) { if (itemType == typeof(MenuTreeNode)) { return new MenuTreeNode(); } return base.CreateInstance(itemType); } protected override string GetDisplayText(object value) { MenuTreeNode node = value as MenuTreeNode; if (node != null) { return "MenuTreeNode: " + node.Text; } return base.GetDisplayText(value); } }
}
[edit] After moving the Treeview to another project, all goes fine. Don't ask me why...
But: only the properties Text and Description are saved, because the designer does not create local variables for each added node. How can I achieve this?
[edit] Finally, I got it to work! thanks to this: http://netcode.ru/dotnet/?lang=&katID=30&skatID=283&artID=7827
The solution was to remove the typeof(string) from the TypeConvertor, and when the type is InstanceDescriptor, just return the default constructor.
Finally, I got it to work! thanks to this article: http://netcode.ru/dotnet/?lang=&katID=30&skatID=283&artID=7827
The solution was to remove the typeof(string) from the TypeConvertor, and when the type is InstanceDescriptor, just returning the default constructor does the job.