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所有的重载设置字段作为参数传递到指定的值,而属性提高INotifyPropertyChanged.PropertyChanged事件。
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如果一个字段已经成功地改变,setProperty方法中返回真。一些重载也需要一个回调方法作为参数。调用该回调后场已经改变。
- 手动设置一个基本的私有字段,然后调用的BindableBase.RaisePropertyChanged方法重载之一。
所有RaisePropertyChanged方法重载需要作为输入参数,这些属性提高INotifyPropertyChanged.PropertyChanged事件。
using System; using System.Collections.Generic; using System.Linq; using DevExpress.Xpf.Mvvm; public class BindableObject : BindableBase { //The property's setter below uses the SetProperty method, which does the following: //1. Changes the underlying private field. //2. Raises a change notification for the property, whose name is retrieved from the expression: () => StringProperty. //This is the preferable method for setting a property in most cases, because it provides strong typing. //The method is slightly slower than passing the property name as a string (see the declaration of StringProperty2). string stringProperty; public string StringProperty { get { return stringProperty; } set { SetProperty(ref stringProperty, value, () => StringProperty); } } //The property's setter below uses the SetProperty method, which does the following: //1. Changes the underlying private field. //2. Raises a change notification for the property with the specified name. //This method is slightly faster than the previous variant, but does not provide strong typing. string stringProperty2; public string StringProperty2 { get { return stringProperty2; } set { SetProperty(ref stringProperty2, value, "StringProperty2"); } } //The property's setter below uses the SetProperty method, which does the following: //1. Changes the underlying private field. //2. Invokes your callback method (OnStringProperty3Changed) if the property has been changed. //3. Raises a change notification for the property, whose name is retrieved from the expression: () => StringProperty3. string stringProperty3; public string StringProperty3 { get { return stringProperty3; } set { SetProperty(ref stringProperty3, value, () => StringProperty3, OnStringProperty3Changed); //An alternative form: SetProperty(ref stringProperty3, value, () => StringProperty3, () => OnStringProperty3Changed()); } } private void OnStringProperty3Changed() { } //The property's setter below uses the SetProperty method, which does the following: //1. Changes the underlying private field. //2. Raises a change notification for the property, whose name is retrieved from the expression: () => StringProperty4. //You can write additional code within the "if" statement, which will be executed after the property has changed. string stringProperty4; public string StringProperty4 { get { return stringProperty4; } set { if (SetProperty(ref stringProperty4, value, () => StringProperty4)) { //The SetProperty method returns true if the property has been changed. ///Do “something” after the property has changed. //... } } } //The following property's setter does the following: //1. Changes the underlying private field. //2. Raises a change notification via the RaisePropertyChanged method. string stringProperty5; public string StringProperty5 { get { return stringProperty5; } set { if (stringProperty5 == value) return; stringProperty5 = value; RaisePropertyChanged("StringProperty5"); //An alternative form using a lambda expression, which provides strong typing: RaisePropertyChanged(() => StringProperty5); //Do “something” after the property has changed. //... } } //The following property's setter changes a property, and raises change notifications for this property and its dependent properties: //1. Changes the underlying private field (stringProperty6). //2. Raises change notifications for StringProperty and StringProperty2. //3. Raises a change notification for StringProperty6. //This is the preferable variant in most cases, because it features strong typing. //The method is slightly slower than passing the property name as a string (see the implementation of StringProperty7). string stringProperty6; public string StringProperty6 { get { return stringProperty6; } set { SetProperty(ref stringProperty6, value, () => StringProperty6, () => RaisePropertiesChanged(() => StringProperty, () => StringProperty2)); //An alternative form that is easier to read: if (SetProperty(ref stringProperty6, value, () => StringProperty6)) { RaisePropertiesChanged(() => StringProperty, () => StringProperty2); } } } //The following property's setter changes the property and raises change notifications for this property and its dependent properties: //1. Changes the underlying private field (stringProperty7). //2. Raises a change notification for StringProperty7. //3. Raises change notifications for StringProperty and StringProperty2. //This is a quicker alternative to the previous example, but does not provide strong typing. string stringProperty7; public string StringProperty7 { get { return stringProperty7; } set { if (SetProperty(ref stringProperty7, value, () => StringProperty7)) { RaisePropertiesChanged("StringProperty", "StringProperty2"); } } } }
该代码来自官网