问题:如下,我定义了一个对象,默认设置属性WindowSize ,WindowSize 为不可见,通过改变SaveOnClose的值,动态的改变不可见的属性的显示和隐藏。
[DefaultPropertyAttribute("SaveOnClose")] public class AppSettings{ private bool saveOnClose = false; private Size windowSize = new Size(100,100); private Font windowFont = new Font("宋体", 9, FontStyle.Regular); [CategoryAttribute("文档设置"), DefaultValueAttribute(true)] public bool SaveOnClose { get { return saveOnClose; } set { saveOnClose = value;} } [CategoryAttribute("文档设置"), Browsable(false)] public Size WindowSize { get { return windowSize; } set { windowSize = value;} } [CategoryAttribute("文档设置"), Browsable(false),] public Font WindowFont { get {return windowFont; } set { windowFont = value;} } }
那么,现在,既然有属性的特性Browsable,可以设置属性的显示和隐藏,我们就可以通过改变这个参数的值,从而达到我们想要的效果。如下:
void SetPropertyVisibility(object obj, string propertyName, bool visible) { Type type = typeof(BrowsableAttribute); PropertyDescriptorCollection props = TypeDescriptor.GetProperties(obj); AttributeCollection attrs = props[propertyName].Attributes; FieldInfo fld = type.GetField("browsable", BindingFlags.Instance | BindingFlags.NonPublic); fld.SetValue(attrs[type], visible); } void SetPropertyReadOnly(object obj, string propertyName, bool readOnly) { Type type = typeof(System.ComponentModel.ReadOnlyAttribute); PropertyDescriptorCollection props = TypeDescriptor.GetProperties(obj); AttributeCollection attrs = props[propertyName].Attributes; FieldInfo fld = type.GetField("isReadOnly", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.CreateInstance); fld.SetValue(attrs[type], readOnly); }
以上方法,不用我说。一看就知道用途了吧,通过如下方法去调用:
private void propertyGrid1_PropertyValueChanged(object s, PropertyValueChangedEventArgs e) { var item = propertyGrid1.SelectedObject; bool b = (bool)e.ChangedItem.Value; if (b) { SetPropertyVisibility(item, "WindowSize", b);//WindowSize必须是自定义属性中的属性名,如下也是 SetPropertyVisibility(item, "WindowFont", b); //SetPropertyReadOnly(item, "WindowFont", b); } else { SetPropertyVisibility(item, "WindowSize", b); SetPropertyVisibility(item, "WindowFont", b); //SetPropertyReadOnly(item, "WindowFont", b); } propertyGrid1.SelectedObject = item; }
通过以上方法就可以达到效果了。 需要注意几点:
1.SetPropertyVisibility方法,SetPropertyReadOnly方法中的参数分别指:(item,’自定义属性对象中的某个属性名‘,值)
2.上述方法调用完后,记得需要再次 propertyGrid1.SelectedObject = item; 否则,是没有效果的
参考文献:http://bbs.csdn.net/topics/350150747