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我試圖使用DataGridView來顯示對象列表。 在我想呈現屬性的類中，我有一些C＃屬性，並且我也想動態地創建屬性，原因有些。試圖將DataGridView與ICustomTypeDescriptor一起使用
這裏我有一個例子，它適用於C＃屬性（FeatureId），但動態創建的屬性（Name）返回所有實例的第一個實例的值。 爲什麼？
首先實現了ICustomPropertyDescriptor接口的類
public abstract class PropertyPresentationSubBase : ICustomTypeDescriptor
{
public String GetClassName()
{
return TypeDescriptor.GetClassName(this, true);
}
public AttributeCollection GetAttributes()
{
return TypeDescriptor.GetAttributes(this, true);
}
public String GetComponentName()
{
return TypeDescriptor.GetComponentName(this, true);
}
public TypeConverter GetConverter()
{
return TypeDescriptor.GetConverter(this, true);
}
public EventDescriptor GetDefaultEvent()
{
return TypeDescriptor.GetDefaultEvent(this, true);
}
public PropertyDescriptor GetDefaultProperty()
{
return TypeDescriptor.GetDefaultProperty(this, true);
}
public object GetEditor(Type editorBaseType)
{
return TypeDescriptor.GetEditor(this, editorBaseType, true);
}
public EventDescriptorCollection GetEvents(Attribute[] attributes)
{
return TypeDescriptor.GetEvents(this, attributes, true);
}
public EventDescriptorCollection GetEvents()
{
return TypeDescriptor.GetEvents(this, true);
}
public virtual PropertyDescriptorCollection GetProperties(Attribute[] attributes)
{
PropertyDescriptorCollection rtn = TypeDescriptor.GetProperties(this);
//rtn = FilterReadonly(rtn, attributes);
return new PropertyDescriptorCollection(rtn.Cast<PropertyDescriptor>().ToArray());
}
public virtual PropertyDescriptorCollection GetProperties()
{
return TypeDescriptor.GetProperties(this, true);
}
public object GetPropertyOwner(PropertyDescriptor pd)
{
return this;
}
[Browsable(false)]
public PropertyPresentationSubBase Parent
{
get
{
return m_Parent;
}
set
{
m_Parent = value;
}
}
PropertyPresentationSubBase m_Parent = null;
[Browsable(false)]
public Type ValueType
{
get
{
return valueType;
}
set
{
valueType = value;
}
}
private Type valueType = null;
[Browsable(false)]
public string Name
{
get
{
return sName;
}
set
{
sName = value;
}
}
public abstract object GetValue();
private string sName = string.Empty;
public abstract void Change(object value);
}
}
我還具有從的PropertyDescriptor
public class MyCustomPropertyDescriptor : PropertyDescriptor
{
PropertyPresentationSubBase m_Property;
public MyCustomPropertyDescriptor(PropertyPresentationSubBase myProperty, Attribute[] attrs, int propertyNo)
: base(myProperty.Name + propertyNo, attrs)
{
m_Property = myProperty;
}
#region PropertyDescriptor specific
public override bool CanResetValue(object component)
{
return false;
}
public override string Name
{
get
{
return "MyName";
}
}
public override Type ComponentType
{
get
{
return null;
}
}
public override object GetValue(object component)
{
return m_Property.GetValue();
}
public override string Description
{
get
{
return "Description";
}
}
public object Value
{
get
{
return m_Property;
}
}
public override string Category
{
get
{
return "Category";
}
}
public override string DisplayName
{
get
{
return m_Property.Name;
}
}
public override bool IsReadOnly
{
get
{
return false;
}
}
public override void ResetValue(object component)
{
//Have to implement
}
public override bool ShouldSerializeValue(object component)
{
return false;
}
public override void SetValue(object component, object value)
{
m_Property.Change(value);
}
public override Type PropertyType
{
get
{
if ((m_Property != null) && (m_Property.ValueType != null))
{
return m_Property.ValueType;
}
else
{
return System.Type.Missing.GetType();
}
}
}
#endregion
}
保存數據的小型類繼承的類：
public class QuadriFeatureItem
{
public QuadriFeatureItem(int featureId, string name)
{
m_featureId = featureId;
m_name = name;
}
public int m_featureId;
public string m_name;
}
我的類被髮送到網格（同時含有FEATUREID屬性和動態創建的屬性）
class FeaturePropertyPresentation : PropertyPresentationSubBase
{
public int FeatureId
{
get
{
return m_feature.m_featureId;
}
set { m_feature.m_featureId = value; }
}
public FeaturePropertyPresentation(QuadriFeatureItem item)
{
m_feature = item;
}
private QuadriFeatureItem m_feature;
public override PropertyDescriptorCollection GetProperties(Attribute[] attributes)
{
PropertyDescriptorCollection rtn = base.GetProperties(attributes);
CreateNameAttribute(ref rtn, attributes);
return rtn;
}
private void CreateNameAttribute(ref PropertyDescriptorCollection pdc, Attribute[] attributes)
{
NameProperty namePres = null;
namePres = new NameProperty(m_feature, this);
pdc.Add(new MyCustomPropertyDescriptor(namePres, attributes, pdc.Count));
}
public override void Change(object value)
{
throw new NotImplementedException();
}
public override object GetValue()
{
return this;
}
}
實現該nameproperty一類：
class NameProperty : PropertyPresentationSubBase
{
public NameProperty(QuadriFeatureItem feature, FeaturePropertyPresentation parent)
: base()
{
m_quadriFeatureItem = feature;
Parent = parent;
ValueType = typeof(string);
}
private QuadriFeatureItem m_quadriFeatureItem;
public override void Change(object value)
{
m_quadriFeatureItem.m_name = (string)value;
}
public override object GetValue()
{
return m_quadriFeatureItem.m_name;
}
}
而我的表單代碼：
public Form1()
{
InitializeComponent();
ShowGrid();
}
private void ShowGrid()
{
QuadriFeatureItem no1 = new QuadriFeatureItem(1, "Nummer1");
QuadriFeatureItem no2 = new QuadriFeatureItem(2, "Nummer2");
QuadriFeatureItem no3 = new QuadriFeatureItem(3, "Nummer3");
BindingSource source = new BindingSource();
FeaturePropertyPresentation no1Pres = new FeaturePropertyPresentation(no1);
FeaturePropertyPresentation no2Pres = new FeaturePropertyPresentation(no2);
FeaturePropertyPresentation no3Pres = new FeaturePropertyPresentation(no3);
source.Add(no1Pres);
source.Add(no2Pres);
source.Add(no3Pres);
dataGridView1.DataSource = source;
Show();
}
但網格對所有行顯示「Nummer1」。爲什麼？我在PropertyGrid中使用這個表示類，它工作正常。我也在PropertyGrid中使用這個MyCustomPropertyDescriptor。
我希望現在能夠在datagridview中重用這個presentationclasses和MyCustomPropertyDescriptor。是否可以在MyCustomPropertyDescriptor或PropertyPresentationSubBase中進行任何修改？
也許它與'ICustomTypeDescriptor'的實現有關，所以最好發佈你的實現。 –
這絕對是可能的，但你需要展示你的實現。 –
如何顯示「MyCustomPropertyDescriptor」的代碼？看，如果你需要幫助，你需要向我們提供足夠的信息。我只能說目前的問題在於你的代碼。 –