C# PropertyGrid使用案例详解
时间：2022-01-26 10:14:18|栏目：.NET代码|点击： 次
1. 只有public的property能显示出来，可以通过BrowsableAttribute来控制是否显示，通过CategoryAttribute设置分类，通过DescriptionAttribute设置描述，Attribute可以加在Class上，也可以加在属性上，属性上的Attribute优先级更高；
2. enum会自动使用列表框表示；
3. 自带输入有效性检查，如int类型输入double数值，会弹出提示对话框；
4. 基本类型Array：增加删除只能通过弹出的集合编辑器，修改可以直接展开，值为null时，可以通过集合编辑器创建；
5. 基本类型List：增删改都只能通过集合编辑器，值为null时，能打开集合编辑器，但不能保存结果，所以必须初始化；
6. ReadOnlyAttribute设置为true时，显示为灰色；对List无效，可以打开集合编辑器，在集合编辑器内可以进行增删改；应用于Array时，不能打开集合编辑器，即不能增删，但可以通过展开的方式修改Array元素；
7. 对象：值显示Object.ToString()；Class上加了[TypeConverter(typeof(ExpandableObjectConverter))]之后（也可以加在属性上），才能展开编辑，否则显示为灰色只读；不初始化什么也干不了；
8. 基类类型派生类对象：与普通对象没有区别，[TypeConverter(typeof(ExpandableObjectConverter))]加在基类上即可；
9. 对象Array：增加删除只能通过弹出的集合编辑器，修改可以直接展开，值为null时，可以通过集合编辑器创建；
10. 对象List：增加删除修改只能通过弹出的集合编辑器，值为null时，能打开集合编辑器，但不能保存结果，所以必须初始化；
11. Hashtable和Dictionary能打开集合编辑器，但不能编辑；
12. 通过MyDoubleConverter实现Double类型只显示小数点后两位：
public class MyDoubleConverter : DoubleConverter
{
public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
{
if (destinationType == typeof(string))
{
return string.Format("{0:0.00}", value);
}
return base.ConvertTo(context, culture, value, destinationType);
}
}
13. 通过TypeConverter实现用字符串表示对象
[TypeConverter(typeof(StudentConverter))]
public class Student
{
public Student(string name, int age)
{
Name = name;
Age = age;
}
public string Name { get; set; }
public int Age { get; set; }
public static Student FromString(string s)
{
string name = "Default";
int age = 0;
string[] splits = s.Split(',');
if (splits.Length == 2)
{
name = splits[0];
int.TryParse(splits[1], out age);
}
return new Student(name, age);
}
public override string ToString()
{
return string.Format("{0},{1}", Name, Age);
}
}
public class StudentConverter : TypeConverter
{
public override bool CanConvertFrom(System.ComponentModel.ITypeDescriptorContext context, Type sourceType)
{
if (sourceType == typeof(string))
{
return true;
}
return base.CanConvertFrom(context, sourceType);
}
public override object ConvertFrom(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value)
{
Student result = null;
if ((value as string) != null)
{
result = Student.FromString(value as string);
}
return result;
}
public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
{
if (destinationType == typeof(string))
{
return true;
}
return base.CanConvertTo(context, destinationType);
}
public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destinationType)
{
if (destinationType == typeof(string))
{
return value.ToString();
}
return base.ConvertTo(context, culture, value, destinationType);
}
}
14. 使用UITypeEditor实现文件或目录选择
// 需要在项目里添加引用：程序集|框架|System.Design
[Editor(typeof(FileNameEditor), typeof(UITypeEditor))]
public string FileName { get; set; }
[Editor(typeof(FolderNameEditor), typeof(UITypeEditor))]
public string FolderName { get; set; }
15. 使用自定义的下拉式编辑界面
public class MyAddress
{
public string Province { get; set; }
public string City { get; set; }
public override string ToString()
{
return string.Format("{0}-{1}", Province, City);
}
}
public class MyAddressEditor : UITypeEditor
{
public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
{
return UITypeEditorEditStyle.DropDown;
}
public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
{
IWindowsFormsEditorService service = provider.GetService(typeof(IWindowsFormsEditorService)) as IWindowsFormsEditorService;
if (service != null)
{
service.DropDownControl(new MyEditorControl(value as MyAddress));
}
return value;
}
}
// 实现两个ComboBox用来编辑MyAddress的属性
public partial class MyEditorControl : UserControl
{
private MyAddress _address;
public MyEditorControl(MyAddress address)
{
InitializeComponent();
_address = address;
comboBoxProvince.Text = _address.Province;
comboBoxCity.Text = _address.City;
}
private void comboBoxProvince_SelectedIndexChanged(object sender, EventArgs e)
{
_address.Province = comboBoxProvince.Text;
}
private void comboBoxCity_SelectedIndexChanged(object sender, EventArgs e)
{
_address.City = comboBoxCity.Text;
}
}
// MyAddress属性声明
[Editor(typeof(MyAddressEditor), typeof(UITypeEditor))]
public MyAddress Address { get; set; }
效果如图：
16. 实现弹出式编辑对话框，只要将UserControl改成Form，EditStyle改成Modal，service.DropDownControl改成service.ShowDialog
public partial class MyEditorForm : Form
{
private MyAddress _address;
public MyEditorForm(MyAddress address)
{
InitializeComponent();
_address = address;
comboBoxProvince.Text = _address.Province;
comboBoxCity.Text = _address.City;
}
private void comboBoxProvince_SelectedIndexChanged(object sender, EventArgs e)
{
_address.Province = comboBoxProvince.Text;
}
private void comboBoxCity_SelectedIndexChanged(object sender, EventArgs e)
{
_address.City = comboBoxCity.Text;
}
}
public class MyAddressEditor : UITypeEditor
{
public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
{
return UITypeEditorEditStyle.Modal;
}
public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
{
IWindowsFormsEditorService service = provider.GetService(typeof(IWindowsFormsEditorService)) as IWindowsFormsEditorService;
if (service != null)
{
service.ShowDialog(new MyEditorForm(value as MyAddress));
}
return value;
}
}
17. 密码表示：[PasswordPropertyText(true)]
18. 动态显示/隐藏属性
class MyData
{
public static void SetPropertyAttribute(object obj, string propertyName, Type attrType, string attrField, object value)
{
PropertyDescriptorCollection props = TypeDescriptor.GetProperties(obj);
Attribute attr = props[propertyName].Attributes[attrType];
FieldInfo field = attrType.GetField(attrField, BindingFlags.Instance | BindingFlags.NonPublic);
field.SetValue(attr, value);
}
private bool _ShowPassword = false;
public bool ShowPassword
{
get { return _ShowPassword; }
set
{
_ShowPassword = value;
SetPropertyAttribute(this, "Password", typeof(BrowsableAttribute), "browsable", _ShowPassword);
}
}
[PasswordPropertyText(true)]
[Browsable(true)]
public string Password { get; set; }
}
public partial class MainFrm : Form
{
// 不添加PropertyValueChanged事件，不能实现动态显示/隐藏
private void myData_PropertyValueChanged(object s, PropertyValueChangedEventArgs e)
{
this.myData.SelectedObject = this.myData.SelectedObject;
}
}
19. 提供下拉选项的string
public class ListStringConverter : StringConverter
{
public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
{
return true;
}
public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
{
return new StandardValuesCollection(new string[] { "A", "B" });
}
public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
{
return false;
}
}
[TypeConverter(typeof(ListStringConverter))]
public string Name { get; set; }
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