blocks|key|2904403|text|您可以使用null+coalescing+operator。如果左操作数为空，则此运算符返回右操作数。因此，您可以在CheckBox处于状态时返回false+(当IsChecked属性的值设置为null时)：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2904404|if+(chkRevLoop.IsChecked+??+false)
{

}|code-block|syntax|javascript|2904405|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/null-conditional-operator^0|1M|8|21|5|29|9|5|O|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|F|3|G|5|H|7|12|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|13|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R]]]]

You can use <a href="https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/null-conditional-operator" rel="noreferrer">null coalescing operator</a>. This operator returns right-hand operand if the left-hand operand is null. So you can return <code>false</code> when the <code>CheckBox</code> is in <a href="https://msdn.microsoft.com/en-us/library/system.windows.controls.primitives.togglebutton.ischecked(v=vs.110).aspx" rel="noreferrer">indeterminate</a> state (when the value of <code>IsChecked</code> property is set to null):

<pre><code>if (chkRevLoop.IsChecked ?? false)
{

}
</code></pre>

blocks|key|129737|text|您必须完成从bool?到bool的转换，才能使其正常工作：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|129738|if((bool)(chkRevLoop.IsChecked)){}|code-block|syntax|javascript|129739|因为它已经是一个bool条件，所以你不需要放入true，false，因为如果它是true，那么只有它会进入这个if条件，否则就不是。因此，甚至不需要将chkRevLoop.IsChecked+==+true放在这里，默认情况下，您是通过将IsChecked放入==true来请求IsChecked的|129740|entityMap^0|6|5|C|4|0|0|8|4|23|S|3B|9|3M|6|3V|9|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]|$9|Z|A|10|B|C]|$9|11|A|12|B|C]|$9|13|A|14|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|N|$]]

You have to do this conversion from <code>bool?</code> to <code>bool</code>, to make it work:

<pre><code>if((bool)(chkRevLoop.IsChecked)){}
</code></pre>

Since it is already a <code>bool</code> condition you need not to put true false because if it is true then only it will come inside this if condition else not.
so, no need to even put <code>chkRevLoop.IsChecked == true</code> here, you are by default asking <code>==true</code> by puttin <code>IsChecked</code>

blocks|key|2904461|text|已经有多个答案了，但这里有另一个替代方案|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2904462|if+(chkRevLoop.IsChecked.GetValueOrDefault())+{}|code-block|syntax|javascript|2904463|来自MSDN|offset|length|2904464|entityMap|0|LINK|mutability|MUTABLE|url|https://msdn.microsoft.com/en-us/library/72cec0e0(v=vs.110).aspx^0|0|0|2|4|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

Multiple answers already but here is another alternative

<pre><code>if (chkRevLoop.IsChecked.GetValueOrDefault()) {}
</code></pre>

From <a href="https://msdn.microsoft.com/en-us/library/72cec0e0(v=vs.110).aspx" rel="nofollow noreferrer">MSDN</a>

blocks|key|2904448|text|bool?可以为true、false或null，bool只能为true或false。?使类型“可为空”，并在通常不能为空的情况下添加null作为可能性，因此您可能只需使用|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2904449|if+((bool)chkRevLoop.IsChecked+==+true){}|code-block|syntax|javascript|2904450|或|2904451|if+(chkRevLoop.IsChecked+==+(bool?)true){}|2904452|让它匹配并工作。第二种可能更好，因为我不知道如果IsChecked为null，转换会发生什么|2904453|entityMap^0|0|5|O|4|16|1|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|10|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|11|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|12|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|13|8|@]|D|@]|E|$]]]|R|$]]

A <code>bool?</code> can be true, false or null, while <code>bool</code> can only be true or false. <code>?</code> makes a type "nullable" and adds null as a possibility when it normally isn't, so you can probably just use

<pre><code>if ((bool)chkRevLoop.IsChecked == true){}
</code></pre>

or

<pre><code>if (chkRevLoop.IsChecked == (bool?)true){}
</code></pre>

to make it match up and work. The second is probably better, since I don't know what would happen in the cast if IsChecked is null

blocks|key|131332|text|考虑检查属性是否有值：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|131333|var+isChecked+=+chkRevLoop.IsChecked.HasValue+?+chkRevLoop.IsChecked+:+false;

if+(isChecked+==+true){}|code-block|syntax|javascript|131334|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Consider checking if the property has a value:

<pre><code>var isChecked = chkRevLoop.IsChecked.HasValue ? chkRevLoop.IsChecked : false;

if (isChecked == true){}
</code></pre>

blocks|key|2904416|text|CheckBox的IsChecked属性是可为空的布尔值。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2904417|public+bool?+IsChecked+{+get;+set;+}|code-block|syntax|javascript|2904418|创建一个可以为空的布尔值，并将其等同于您。|2904419|代码|2904420|bool?+NullableBool+=+chkRevLoop.IsChecked;
if(NullableBool+==+true)++++{++++}|2904421|entityMap^0|9|9|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|W|8|@]|D|@]|E|$]]|$1|M|3|N|5|6|7|X|8|@]|D|@]|E|$]]|$1|O|3|P|5|H|7|Y|8|@]|D|@]|E|$I|J]]|$1|Q|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|R|$]]

<code>IsChecked</code> property of CheckBox is Nullable boolean.

<pre><code>public bool? IsChecked { get; set; }
</code></pre>

Create a Nullable boolean and equate it will work for you.

<h2>Code</h2>

<pre><code>bool? NullableBool = chkRevLoop.IsChecked;
if(NullableBool == true) { }
</code></pre>

blocks|key|131886|text|一行代码就足以检查单选按钮是否被选中：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|131887|string+status+=+Convert.ToBoolean(RadioButton.IsChecked)+?+"Checked"+:+"Not+Checked";|code-block|syntax|javascript|131888|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

One line is enough to check if the radio button is checked or not:

<pre><code>string status = Convert.ToBoolean(RadioButton.IsChecked) ? "Checked" : "Not Checked";
</code></pre>

blocks|key|131403|text|您应该使用可以为空的对象。因为可以将IsChecked属性分配给三个不同的值:+Null、true和false|type|unstyled|depth|inlineStyleRanges|entityRanges|data|131404|Nullable<bool>+isChecked++=+new+Nullable<bool>();+
isChecked+=+chkRevLoop.IsChecked;+

if+(isChecked.HasValue+&&+isChecked.Value)
{


}|code-block|syntax|javascript|131405|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You should use Nullable object. Because IsChecked property can be assigned to three different value: Null, true and false 

<pre><code>Nullable&lt;bool&gt; isChecked = new Nullable&lt;bool&gt;(); 
isChecked = chkRevLoop.IsChecked; 

if (isChecked.HasValue &amp;&amp; isChecked.Value)
{


}
</code></pre>

I'm not talking about an event handler for this, but rather a simple <code>If Statement</code> checking if the <code>CheckBox</code> has been checked. So far I have:

<pre><code>if (chkRevLoop.IsChecked == true){}
</code></pre>

But that raises the error:

<blockquote>
 Cannot implicitly convert type 'bool?' to 'bool'. An explicit conversion exists (are you missing a cast?)
</blockquote>

Is there a way to do this that I'm missing?

WPF Checkbox check IsChecked

我讨论的不是一个事件处理程序，而是一个简单的If Statement检查CheckBox是否已经被检查。到目前为止，我有：if (chkRevLoop.IsChecked == true){}但这引发了错误：不能隐式转换类型'bool?‘为了“bool”。存在显式转换(是否缺少强制转换？)有没有办法解决我错过的这个问题？

问WPF复选框检查IsChecked
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