blocks|key|2098048|text|由于您只是执行一些快速计算，因此通过锁定适当的对象来确保原子性：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2098049|long+total+=+Products.LongCount();
long+current+=+0;
double+Progress+=+0.0;
var+lockTarget+=+new+object();

Parallel.ForEach(Products,+product+=>
{
++++try
++++{
++++++++var+price+=+GetPrice(SystemAccount,+product);
++++++++SavePrice(product,price);
++++}
++++finally
++++{
++++++++lock+(lockTarget)+{
++++++++++++Progress+=+%2B%2Bthis.current+/+total;
++++++++}
++++}});|code-block|syntax|javascript|2098050|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|$]]

Since you are just doing a few quick calculations, ensure atomicity by locking on an appropriate object:

<pre><code>long total = Products.LongCount();
long current = 0;
double Progress = 0.0;
var lockTarget = new object();

Parallel.ForEach(Products, product =&gt;
{
 try
 {
 var price = GetPrice(SystemAccount, product);
 SavePrice(product,price);
 }
 finally
 {
 lock (lockTarget) {
 Progress = ++this.current / total;
 }
 }});
</code></pre>

blocks|key|2933484|text|在主体中不使用任何阻塞的解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2933485|long+total+=+Products.LongCount();
BlockingCollection<MyState>+states+=+new+BlockingCollection<MyState>();

Parallel.ForEach(Products,+()+=>
{
++++MyState+myState+=+new+MyState();
++++states.Add(myState);
++++return+myState;
},
(i,+state,+arg3,+myState)+=>
{
++++try
++++{
++++++++var+price+=+GetPrice(SystemAccount,+product);
++++++++SavePrice(product,price);
++++}
++++finally
++++{
++++++++myState.value%2B%2B;
++++++++return+myState;
++++}
},
i+=>+{+}
);|code-block|syntax|javascript|2933486|然后，访问当前进度：|2933487|(float)states.Sum(state+=>+state.value)+/+total|2933488|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|$]]

A solution without using any blocking in the body:

<pre><code>long total = Products.LongCount();
BlockingCollection&lt;MyState&gt; states = new BlockingCollection&lt;MyState&gt;();

Parallel.ForEach(Products, () =&gt;
{
 MyState myState = new MyState();
 states.Add(myState);
 return myState;
},
(i, state, arg3, myState) =&gt;
{
 try
 {
 var price = GetPrice(SystemAccount, product);
 SavePrice(product,price);
 }
 finally
 {
 myState.value++;
 return myState;
 }
},
i =&gt; { }
);
</code></pre>

Then, to access the current progress:

<pre><code>(float)states.Sum(state =&gt; state.value) / total
</code></pre>

blocks|key|2933505|text|Jon的解决方案很好，如果你需要像这样简单的同步，你的第一次尝试应该几乎总是使用lock。但是，如果您认为锁定的速度太慢，您应该考虑使用Interlocked之类的工具。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2933506|在本例中，我将使用Interlocked.Increment递增当前计数，并将Progress更改为一个属性：|2933507|private+long+total;
private+long+current;
public+double+Progress
{
++++get
++++{
++++++++if+(total+==+0)
++++++++++++return+0;
++++++++return+(double)current+/+total;
++++}
}

…

this.total+=+Products.LongCount();
this.current+=+0;

Parallel.ForEach(Products,+product+=>
{
++++try
++++{
++++++++var+price+=+GetPrice(SystemAccount,+product);
++++++++SavePrice(product,+price);
++++}
++++finally
++++{
++++++++Interlocked.Increment(ref+this.current);
++++}
});|code-block|syntax|javascript|2933508|此外，你可能想要考虑如何处理异常，我不确定以异常结束的迭代是否应该被算作完成。|2933509|entityMap^0|14|4|1W|B|0|9|L|13|8|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]|$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|V|8|@$9|W|A|X|B|C]|$9|Y|A|Z|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|10|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|11|8|@]|D|@]|E|$]]|$1|O|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|P|$]]

Jon's solution is good, if you need simple synchronization like this, your first attempt should almost always use <code>lock</code>. But if you measure that the locking slows things too much, you should think about using something like <code>Interlocked</code>.

In this case, I would use <code>Interlocked.Increment</code> to increment the current count, and change <code>Progress</code> into a property:

<pre><code>private long total;
private long current;
public double Progress
{
 get
 {
 if (total == 0)
 return 0;
 return (double)current / total;
 }
}

…

this.total = Products.LongCount();
this.current = 0;

Parallel.ForEach(Products, product =&gt;
{
 try
 {
 var price = GetPrice(SystemAccount, product);
 SavePrice(product, price);
 }
 finally
 {
 Interlocked.Increment(ref this.current);
 }
});
</code></pre>

Also, you might want to consider what to do with exceptions, I'm not sure that iterations that ended with an exception should be counted as done.

What is the best way way to track progress in the following 

<pre><code>long total = Products.LongCount();
long current = 0;
double Progress = 0.0;

Parallel.ForEach(Products, product =&gt;
{
 try
 {
 var price = GetPrice(SystemAccount, product);
 SavePrice(product,price);
 }
 finally
 {
 Interlocked.Decrement(ref this.current);
 }});
</code></pre>

I want to update the progress variable from 0.0 to 1.0 (current/total) but i don't want to use anything that would have an adverse effect on the parallelism.

Track progress when using TPL's Parallel.ForEach

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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跟踪以下进度的最佳方法是什么？long total = Products.LongCount();long current = 0;double Progress = 0.0;Parallel.ForEach(Products, product =>{    try    {        var price = Ge...

问使用第三方物流的Parallel.ForEach时跟踪进度
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