在 ViewModel 中创建一个新的 ICommand 对象
两个 ICommand 对象都绑定到 ViewModel。
第一种方法似乎经常使用。
但是第二个节省了一些代码行，但是当刷新 Binding 时它不会每次都创建一个新的 ICommand 对象，这样会浪费资源吗？！
private LightCommand _deleteDocumentCommand;
public LightCommand DeleteDocumentCommand
{
get { return _deleteDocumentCommand ?? (_deleteDocumentCommand = new LightCommand(() => DeleteDocument(), () => CanDeleteDocument)); }
}
public LightCommand DeleteDocumentCommand
{
get { return new LightCommand(() => DeleteDocument(), () => CanDeleteDocument); }
}
Both ICommand objects are bound to a ViewModel.
The first approach seems to be used often.
But the second one saves some lines of code but would it not create everytime a new ICommand object when the Binding is refreshed so its a waste of resources?!
private LightCommand _deleteDocumentCommand;
public LightCommand DeleteDocumentCommand
{
get { return _deleteDocumentCommand ?? (_deleteDocumentCommand = new LightCommand(() => DeleteDocument(), () => CanDeleteDocument)); }
}
public LightCommand DeleteDocumentCommand
{
get { return new LightCommand(() => DeleteDocument(), () => CanDeleteDocument); }
}
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评论（3）
是的，每次引用命令时，您的第二种方法都会创建一个新命令，但我也发现您的第一种方法很难阅读。
我在 ViewModel 中创建命令的首选方法是
它可能会包含更多行代码，但很容易阅读和理解。此外，通常我所有的公共属性/命令都是由宏生成的，并转储到
#region Properties区域中，该区域在我使用 ViewModel 的整个过程中都保持折叠状态，因此我不必滚动页面获取/设置方法。Yes your 2nd method creates a new command every time the command is referenced, but I also find your 1st method rather hard to read.
My preferred way to make a command in the ViewModel is
It might be more lines of code, but it is easy to read and understand. Besides, usually all my public Properties/Commands are generated by macros and dumped into a
#region Propertiesarea that stays collapsed the entire time I work with the ViewModel, so I don't have to scroll through pages of get/set methods.是的，会的。您最好将其实例化一次，这样您就可以得到如下所示的内容：
然后在我们的 VM 实例化中分配给它。或者你可以使用你的第一个例子。
yes it would. You are better off instantiating it once, so that you have something like this:
and then in our VM instantiation you assign to it. Or you could use your first example.
我假设您正在寻找验证，这是正确的：
每次刷新绑定（或调用命令）时，都会实例化一个新对象。这看起来明显是资源浪费。
I assume you're looking for verification, and that's correct:
Everytime the Binding is refreshed, (or the command is called), a new object is instantiated. It looks like a clear waste of resources.