blocks|key|737750|text|通常可以在运行时更改视图的属性：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|737751|(Button)+item+=+(Button)+findViewById(R.id.idBut);|code-block|syntax|javascript|737752|然后..。|737753|item.setVisibility(false)|737754|但|737755|如果要从ContextMenu修改选项的可见性，请在按下按钮时激活标志，然后在onCreateContextMenu中可以执行以下操作：|737756|+@Override
++++++++public+void+onCreateContextMenu(ContextMenu+menu,+
++++++++++++++++View+v,ContextMenu.ContextMenuInfo+menuInfo)+{

++++++++++++super.onCreateContextMenu(menu,+v,+menuInfo);

++++++++++++++++menu.setHeaderTitle(R.string.context_title);

++++++++++++++++if+(flagIsOn())+{
++++++++++++++++++++addMenuItem(menu,+"Option+available",+true);
++++++++++++++++}+else+{
++++++++++++++++++++Toast.makeText(this,+"Option+not+available",+500).show();
++++++++++++++++}

++++++++}|737757|我希望这能帮到你|737758|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|Y|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|Z|8|@]|9|@]|A|$]]|$1|O|3|P|5|D|7|10|8|@]|9|@]|A|$E|F]]|$1|Q|3|R|5|6|7|11|8|@]|9|@]|A|$]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

Generally can change the properties of your views in runtime:

<pre><code>(Button) item = (Button) findViewById(R.id.idBut);
</code></pre>

and then...

<pre><code>item.setVisibility(false)
</code></pre>

but

if you want to modify de visibility of the options from the ContextMenu, on press your button, you can activate a flag, and then in onCreateContextMenu you can do something like this:

<pre><code> @Override
 public void onCreateContextMenu(ContextMenu menu, 
 View v,ContextMenu.ContextMenuInfo menuInfo) {

 super.onCreateContextMenu(menu, v, menuInfo);

 menu.setHeaderTitle(R.string.context_title);

 if (flagIsOn()) {
 addMenuItem(menu, "Option available", true);
 } else {
 Toast.makeText(this, "Option not available", 500).show();
 }

 }
</code></pre>

I hope this helps

blocks|key|737823|text|您可以在创建选项菜单时将项目另存为变量，然后随意更改其属性。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|737824|private+MenuItem+securedConnection;
private+MenuItem+insecuredConnection;

@Override
public+boolean+onCreateOptionsMenu(Menu+menu)+{
++++MenuInflater+inflater+=+getMenuInflater();
++++inflater.inflate(R.menu.connect_menu,+menu);
++++securedConnection+=+menu.getItem(0);
++++insecuredConnection+=++menu.getItem(1);
++++return+true;
}

public+void+foo(){
+++++++securedConnection.setEnabled(true);
}++++|code-block|syntax|javascript|737825|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 could save the item as a variable when creating the option menu and then change its properties at will.

<pre><code>private MenuItem securedConnection;
private MenuItem insecuredConnection;

@Override
public boolean onCreateOptionsMenu(Menu menu) {
 MenuInflater inflater = getMenuInflater();
 inflater.inflate(R.menu.connect_menu, menu);
 securedConnection = menu.getItem(0);
 insecuredConnection = menu.getItem(1);
 return true;
}

public void foo(){
 securedConnection.setEnabled(true);
} 
</code></pre>

blocks|key|953832|text|在所有android版本中，最简单的方式:使用此选项将菜单操作图标显示为禁用状态，并使其功能也处于禁用状态：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|953833|@Override
public+boolean+onPrepareOptionsMenu(Menu+menu)+{

++++MenuItem+item+=+menu.findItem(R.id.menu_my_item);

++++if+(myItemShouldBeEnabled)+{
++++++++item.setEnabled(true);
++++++++item.getIcon().setAlpha(255);
++++}+else+{
++++++++//+disabled
++++++++item.setEnabled(false);
++++++++item.getIcon().setAlpha(130);
++++}
}|code-block|syntax|javascript|953834|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|$]]

On all android versions, easiest way: use this to SHOW a menu action icon as disabled AND make it FUNCTION as disabled as well:

<pre><code>@Override
public boolean onPrepareOptionsMenu(Menu menu) {

 MenuItem item = menu.findItem(R.id.menu_my_item);

 if (myItemShouldBeEnabled) {
 item.setEnabled(true);
 item.getIcon().setAlpha(255);
 } else {
 // disabled
 item.setEnabled(false);
 item.getIcon().setAlpha(130);
 }
}
</code></pre>

blocks|key|737887|text|简化@Vikas版本|type|unstyled|depth|inlineStyleRanges|entityRanges|data|737888|@Override
public+boolean+onPrepareOptionsMenu+(Menu+menu)+{

++++menu.findItem(R.id.example_foobar).setEnabled(isFinalized);
++++return+true;
}|code-block|syntax|javascript|737889|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|$]]

simplify @Vikas version 

<pre><code>@Override
public boolean onPrepareOptionsMenu (Menu menu) {

 menu.findItem(R.id.example_foobar).setEnabled(isFinalized);
 return true;
}
</code></pre>

blocks|key|737903|text|@Override
public+boolean+onCreateOptionsMenu(Menu+menu)+{
++++//+Inflate+the+menu;+this+adds+items+to+the+action+bar+if+it+is+present.
++++//+getMenuInflater().inflate(R.menu.home,+menu);
++++return+false;
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|737904|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>@Override
public boolean onCreateOptionsMenu(Menu menu) {
 // Inflate the menu; this adds items to the action bar if it is present.
 // getMenuInflater().inflate(R.menu.home, menu);
 return false;
}
</code></pre>

blocks|key|953886|text|++@Override
++++++++public+boolean+onOptionsItemSelected(MenuItem+item)+{

++++++++++++switch+(item.getItemId())+{

++++++++++++++++case+R.id.item_id:

+++++++++++++++++++++++//Your+Code....

++++++++++++++++++++++++item.setEnabled(false);
++++++++++++++++++++++++break;
++++++++++++++}
++++++++++++return+super.onOptionsItemSelected(item);
+++++}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|953887|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code> @Override
 public boolean onOptionsItemSelected(MenuItem item) {

 switch (item.getItemId()) {

 case R.id.item_id:

 //Your Code....

 item.setEnabled(false);
 break;
 }
 return super.onOptionsItemSelected(item);
 }
</code></pre>

blocks|key|953921|text|如果可见菜单|type|unstyled|depth|inlineStyleRanges|entityRanges|data|953922|menu.findItem(R.id.id_name).setVisible(true);|code-block|syntax|javascript|953923|如果隐藏菜单|953924|menu.findItem(R.id.id_name).setVisible(false);|953925|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

If visible menu

<pre><code>menu.findItem(R.id.id_name).setVisible(true);
</code></pre>

If hide menu

<pre><code>menu.findItem(R.id.id_name).setVisible(false);
</code></pre>

blocks|key|738010|text|对一个老问题的更现代的回答：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|738011|MainActivity.kt|offset|length|style|CODE|738012|private+var+myMenuIconEnabled+by+Delegates.observable(true)+{+_,+old,+new+->
++++if+(new+!=+old)+invalidateOptionsMenu()
}

override+fun+onCreate(savedInstanceState:+Bundle?)+{
++++super.onCreate(savedInstanceState)
++++setContentView(R.layout.activity_main)

++++findViewById<Button>(R.id.my_button).setOnClickListener+{+myMenuIconEnabled+=+false+}
}

override+fun+onCreateOptionsMenu(menu:+Menu?):+Boolean+{
++++menuInflater.inflate(R.menu.menu_main_activity,+menu)
++++return+super.onCreateOptionsMenu(menu)
}

override+fun+onPrepareOptionsMenu(menu:+Menu):+Boolean+{
++++menu.findItem(R.id.action_my_action).isEnabled+=+myMenuIconEnabled
++++return+super.onPrepareOptionsMenu(menu)
}|code-block|syntax|javascript|738013|menu_main_activity.xml|738014|<?xml+version="1.0"+encoding="utf-8"?>
<menu+xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item
++++android:id="@%2Bid/action_my_action"
++++android:icon="@drawable/ic_my_icon_24dp"
++++app:iconTint="@drawable/menu_item_icon_selector"
++++android:title="My+title"
++++app:showAsAction="always"+/>
</menu>|738015|menu_item_icon_selector.xml|738016|<?xml+version="1.0"+encoding="utf-8"?>
<selector+xmlns:android="http://schemas.android.com/apk/res/android">
<item+android:color="?enabledMenuIconColor"+android:state_enabled="true"+/>
<item+android:color="?disabledMenuIconColor"+/>|738017|​|738018|attrs.xml|738019|<resources>+++
++++<attr+name="enabledMenuIconColor"+format="reference%7Ccolor"/>
++++<attr+name="disabledMenuIconColor"+format="reference%7Ccolor"/>
</resources>|738020|styles.xml+or+themes.xml|738021|<style+name="AppTheme"+parent="Theme.MaterialComponents.Light.NoActionBar">
++++
++++<item+name="disabledMenuIconColor">@color/white_30_alpha</item>
++++<item+name="enabledMenuIconColor">@android:color/white</item>|738022|entityMap^0|0|0|F|0|0|0|M|0|0|0|R|0|0|0|0|9|0|0|0|O|0|0^^$0|@$1|2|3|4|5|6|7|16|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|17|8|@$D|18|E|19|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|1A|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|1B|8|@$D|1C|E|1D|F|G]]|9|@]|A|$]]|$1|O|3|P|5|J|7|1E|8|@]|9|@]|A|$K|L]]|$1|Q|3|R|5|6|7|1F|8|@$D|1G|E|1H|F|G]]|9|@]|A|$]]|$1|S|3|T|5|J|7|1I|8|@]|9|@]|A|$K|L]]|$1|U|3|V|5|6|7|1J|8|@]|9|@]|A|$]]|$1|W|3|X|5|6|7|1K|8|@$D|1L|E|1M|F|G]]|9|@]|A|$]]|$1|Y|3|Z|5|J|7|1N|8|@]|9|@]|A|$K|L]]|$1|10|3|11|5|6|7|1O|8|@$D|1P|E|1Q|F|G]]|9|@]|A|$]]|$1|12|3|13|5|J|7|1R|8|@]|9|@]|A|$K|L]]|$1|14|3|-4|5|6|7|1S|8|@]|9|@]|A|$]]]|15|$]]

A more modern answer for an old question:

<code>MainActivity.kt</code>

<pre><code>private var myMenuIconEnabled by Delegates.observable(true) { _, old, new -&gt;
 if (new != old) invalidateOptionsMenu()
}

override fun onCreate(savedInstanceState: Bundle?) {
 super.onCreate(savedInstanceState)
 setContentView(R.layout.activity_main)

 findViewById&lt;Button&gt;(R.id.my_button).setOnClickListener { myMenuIconEnabled = false }
}

override fun onCreateOptionsMenu(menu: Menu?): Boolean {
 menuInflater.inflate(R.menu.menu_main_activity, menu)
 return super.onCreateOptionsMenu(menu)
}

override fun onPrepareOptionsMenu(menu: Menu): Boolean {
 menu.findItem(R.id.action_my_action).isEnabled = myMenuIconEnabled
 return super.onPrepareOptionsMenu(menu)
}
</code></pre>

<code>menu_main_activity.xml</code>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"&gt;
&lt;item
 android:id="@+id/action_my_action"
 android:icon="@drawable/ic_my_icon_24dp"
 app:iconTint="@drawable/menu_item_icon_selector"
 android:title="My title"
 app:showAsAction="always" /&gt;
&lt;/menu&gt;
</code></pre>

<code>menu_item_icon_selector.xml</code>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;selector xmlns:android="http://schemas.android.com/apk/res/android"&gt;
&lt;item android:color="?enabledMenuIconColor" android:state_enabled="true" /&gt;
&lt;item android:color="?disabledMenuIconColor" /&gt;
</code></pre>



<code>attrs.xml</code>

<pre><code>&lt;resources&gt; 
 &lt;attr name="enabledMenuIconColor" format="reference|color"/&gt;
 &lt;attr name="disabledMenuIconColor" format="reference|color"/&gt;
&lt;/resources&gt;
</code></pre>

<code>styles.xml or themes.xml</code>

<pre><code>&lt;style name="AppTheme" parent="Theme.MaterialComponents.Light.NoActionBar"&gt;
 &lt;!-- Customize your theme here. --&gt;
 &lt;item name="disabledMenuIconColor"&gt;@color/white_30_alpha&lt;/item&gt;
 &lt;item name="enabledMenuIconColor"&gt;@android:color/white&lt;/item&gt;
</code></pre>

blocks|key|954078|text|我所做的是保存了对onCreateOptionsMenu菜单的引用。这与nir的答案类似，不同之处在于我保存了整个菜单，而不是保存每个单独的项目。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|954079|声明一个菜单Menu+toolbarMenu;。|954080|然后在onCreateOptionsMenu中将菜单保存到您的变量中|954081|@Override
public+boolean+onCreateOptionsMenu(Menu+menu)
{
++++getMenuInflater().inflate(R.menu.main_menu,+menu);
++++toolbarMenu+=+menu;
++++return+true;
}|code-block|syntax|javascript|954082|现在，您可以随时访问菜单及其所有项目。toolbarMenu.getItem(0).setEnabled(false);|954083|entityMap^0|9|J|0|6|H|0|3|J|0|0|J|15|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|V|8|@$9|W|A|X|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|J|3|K|5|L|7|11|8|@]|D|@]|E|$M|N]]|$1|O|3|P|5|6|7|12|8|@$9|13|A|14|B|C]]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|R|$]]

What I did was save a reference to the Menu at <code>onCreateOptionsMenu</code>. This is similar to nir's answer except instead of saving each individual item, I saved the entire menu. 

Declare a Menu <code>Menu toolbarMenu;</code>.

Then in <code>onCreateOptionsMenu</code>save the menu to your variable

<pre><code>@Override
public boolean onCreateOptionsMenu(Menu menu)
{
 getMenuInflater().inflate(R.menu.main_menu, menu);
 toolbarMenu = menu;
 return true;
}
</code></pre>

Now you can access your menu and all of its items anytime you want.
<code>toolbarMenu.getItem(0).setEnabled(false);</code>

I can easily do it when I am using <code>onCreateOptionsMenu</code> or <code>onOptionsItemSelected</code> methods.

But I have a button somewhere in screen, and on clicking that button, it should enable/disable context menu items.

Android: How to enable/disable option menu item on button click?

当我使用onCreateOptionsMenu或onOptionsItemSelected方法时，我可以轻松地做到这一点。但我在屏幕上的某处有一个按钮，单击该按钮时，它应该启用/禁用上下文菜单项。

问Android:如何在按钮点击时启用/禁用选项菜单项？
EN

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问Android:如何在按钮点击时启用/禁用选项菜单项？
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