blocks|key|3043863|text|确定UI线程身份的常见做法是通过Looper#getMainLooper|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3043864|if+(Looper.getMainLooper().getThread()+==+Thread.currentThread())+{
++//+On+UI+thread.
}+else+{
++//+Not+on+UI+thread.
}|code-block|syntax|javascript|3043865|从API23级开始，在主循环中使用新的帮助器方法isCurrentThread，可读性更好一些：|3043866|if+(Looper.getMainLooper().isCurrentThread())+{
++//+On+UI+thread.
}+else+{
++//+Not+on+UI+thread.
}|3043867|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.android.com/reference/android/os/Looper.html|1|https://developer.android.com/reference/android/os/Looper.html#isCurrentThread()^0|G|K|0|0|0|O|F|1|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]]|C|$]]|$1|D|3|E|5|F|7|10|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|11|8|@]|9|@$A|12|B|13|1|14]]|C|$]]|$1|K|3|L|5|F|7|15|8|@]|9|@]|C|$G|H]]|$1|M|3|-4|5|6|7|16|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]|U|$5|P|Q|R|C|$S|V]]]]

Common practice to determine the UI Thread's identity is via <a href="http://developer.android.com/reference/android/os/Looper.html" rel="noreferrer">Looper#getMainLooper</a>:

<pre><code>if (Looper.getMainLooper().getThread() == Thread.currentThread()) {
 // On UI thread.
} else {
 // Not on UI thread.
}
</code></pre>

From API level 23 and up, there's a slightly more readable approach using new helper method <a href="https://developer.android.com/reference/android/os/Looper.html#isCurrentThread()" rel="noreferrer">isCurrentThread</a> on the main looper:

<pre><code>if (Looper.getMainLooper().isCurrentThread()) {
 // On UI thread.
} else {
 // Not on UI thread.
}
</code></pre>

blocks|key|3043873|text|我认为最好的方法是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3043874|+if+(Looper.getMainLooper().equals(Looper.myLooper()))+{
+++++//+UI+thread
+}+else+{
+++++//+Non+UI+thread
+}|code-block|syntax|javascript|3043875|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|$]]

I think that best way is this:

<pre><code> if (Looper.getMainLooper().equals(Looper.myLooper())) {
 // UI thread
 } else {
 // Non UI thread
 }
</code></pre>

blocks|key|308473|text|在API23级，Looper有一个很好的助手方法isCurrentThread。您可以通过这种方式获取mainLooper并查看它是否是当前线程的way：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|308474|Looper.getMainLooper().isCurrentThread()|code-block|syntax|javascript|308475|它实际上与以下内容相同：|308476|Looper.getMainLooper().getThread()+==+Thread.currentThread()|308477|但它的可读性可能更好一些，更容易记忆。|308478|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.android.com/reference/android/os/Looper.html|1|https://developer.android.com/reference/android/os/Looper.html#isCurrentThread())|2|https://developer.android.com/reference/android/os/Looper.html#getMainLooper()^0|8|6|O|F|1F|A|8|6|0|O|F|1|1F|A|2|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]|$9|17|A|18|B|C]]|D|@$9|19|A|1A|1|1B]|$9|1C|A|1D|1|1E]|$9|1F|A|1G|1|1H]]|E|$]]|$1|F|3|G|5|H|7|1I|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1J|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|1K|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1L|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|1M|8|@]|D|@]|E|$]]]|R|$S|$5|T|U|V|E|$W|X]]|Y|$5|T|U|V|E|$W|Z]]|10|$5|T|U|V|E|$W|11]]]]

As of API level 23 the <a href="https://developer.android.com/reference/android/os/Looper.html" rel="noreferrer"><code>Looper</code></a> has a nice helper method <a href="https://developer.android.com/reference/android/os/Looper.html#isCurrentThread()" rel="noreferrer"><code>isCurrentThread</code></a>. You could get the <a href="https://developer.android.com/reference/android/os/Looper.html#getMainLooper()" rel="noreferrer"><code>mainLooper</code></a> and see if it's the one for the current thread this way:

<pre><code>Looper.getMainLooper().isCurrentThread()
</code></pre>

It's practically the same as:

<pre><code>Looper.getMainLooper().getThread() == Thread.currentThread()
</code></pre>

but it could be a bit more readable and easier to remember.

blocks|key|307513|text|public+boolean+onUIThread()+{
++++return+Looper.getMainLooper().isCurrentThread();

}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|307514|但它需要API级别23|unstyled|307515|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>public boolean onUIThread() {
 return <a href="https://developer.android.com/reference/android/os/Looper.html" rel="nofollow noreferrer">Looper</a>.<a href="https://developer.android.com/reference/android/os/Looper.html#getMainLooper()" rel="nofollow noreferrer">getMainLooper()</a>.<a href="https://developer.android.com/reference/android/os/Looper.html#isCurrentThread()" rel="nofollow noreferrer">isCurrentThread()</a>;

}</code></pre>

But it requires API level 23

blocks|key|3257724|text|除了检查循环程序之外，如果您曾经尝试在onCreate()中线程id，您可能会发现UI线程(主线程)+id始终等于1。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|CODE|entityRanges|data|3257725|if+(Thread.currentThread().getId()+==+1)+{
++++//+UI+thread
}
else+{
++++//+other+thread
}|code-block|syntax|javascript|3257726|entityMap^0|4|4|15|9|J|A|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]|$9|Q|A|R|B|C]|$9|S|A|T|B|D]]|E|@]|F|$]]|$1|G|3|H|5|I|7|U|8|@]|E|@]|F|$J|K]]|$1|L|3|-4|5|6|7|V|8|@]|E|@]|F|$]]]|M|$]]

Besides checking looper, if you ever tried to logout thread id in <code>onCreate()</code>, you could find the UI thread(main thread) id always equals to 1. Therefore

<pre><code>if (Thread.currentThread().getId() == 1) {
 // UI thread
}
else {
 // other thread
}
</code></pre>

blocks|key|305492|text|Kotlin的不错的扩展：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|305493|val+Thread.isMain+get()+=+Looper.getMainLooper().thread+==+Thread.currentThread()|code-block|syntax|javascript|305494|所以你只需调用：|305495|Thread.currentThread().isMain|305496|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|$]]

Nice extension for Kotlin:
<pre><code>val Thread.isMain get() = Looper.getMainLooper().thread == Thread.currentThread()
</code></pre>
So you just call:
<pre><code>Thread.currentThread().isMain
</code></pre>

blocks|key|3257674|text|不能在Activity类中使用runOnUiThread方法吗?请参见..|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3257675|http://developer.android.com/reference/android/app/Activity.html#runOnUiThread%2528java.lang.Runnable%2529|3257676|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.android.com/reference/android/app/Activity.html#runOnUiThread%2528java.lang.Runnable%2529^0|3|8|F|D|0|0|2U|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]|$9|S|A|T|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|U|8|@]|D|@$9|V|A|W|1|X]]|E|$]]|$1|H|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|I|$J|$5|K|L|M|E|$N|O]]]]

Couldn't you use the <code>runOnUiThread</code> method in the <code>Activity</code> class?See..

<a href="http://developer.android.com/reference/android/app/Activity.html#runOnUiThread%28java.lang.Runnable%29" rel="nofollow noreferrer">http://developer.android.com/reference/android/app/Activity.html#runOnUiThread%28java.lang.Runnable%29</a>

Is there a robust way to detect if <code>Thread.currentThread()</code> is the Android system UI thread in an application? 
I would like to put some asserts in my model code that asserts that only one thread (eg the ui thread) accesses my state, to assure that no kind of synchronization is necessary.

How to detect UI thread on Android?

Kotlin

有没有一种健壮的方法来检测Thread.currentThread()是否是应用程序中的安卓系统UI线程？我想在我的模型代码中添加一些断言，断言只有一个线程(例如UI线程)访问我的状态，以确保不需要任何类型的同步。

问如何在Android上检测UI线程？
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