静态缓存问题 [英] Static Cache Problem

问题描述

我将我的xml数据缓存到数据集中，如下所示：

Hi,

I am caching my xml data into a data set as given below:

public static void LoadCache()
{
    static DataSet ds = new DataSet();
    ds.ReadXml(HttpContext.Current.Server.MapPath("myXML.xml"));
    HttpRuntime.Cache.Insert("myCache", ds,null, Cache.NoAbsoluteExpiration,
                             Cache.NoSlidingExpiration, CacheItemPriority.High, null);
}

//Method to Call Cache
public DataSet GetXMLData()
{
    if (HttpRuntime.Cache["myCache"] == null)
    {
        LoadCache();
    }
    return (DataSet)HttpRuntime.Cache["myCache"];
}

现在我有一个数据集dsData在我的页面加载中从这个缓存中填充并执行以下操作：

Now I have a dataset dsData In my page load that is filled from this cache and I do the following:

DataView dv = dsData.Tables[0].DefaultView;
dv.RowFilter = "key=0";
DataTable dtTemp = dv.ToTable();
dtTemp.Columns.Add("sort"); //Works fine only once

上面的块只能工作一次，当我刷新页面时，它显示dtTemp中已经存在同名的列。



当我尝试调试我发现缓存数据集ds也包含相同的列。

我无法弄清楚为什么会发生这种情况。

The above chunk works only for once, when I refresh my page it shows Column with same name already exist in dtTemp.

Also when I tried Debugging I found Out that The Cache Dataset ds also contains same column.
I am unable to figure out why this happens.

推荐答案

我修改了我的第一个答案，因为它没有回答这个问题。

我在尝试下面的代码后仍然没有答案。

它可以正常工作我可以看到。

I revised my first answer as it did not answer the question.
I still don't have an answer, after trying the code below.
It works fine as far as I can see.

static DataSet ds = new DataSet();
public static void LoadCache()
{

    DataTable dt = ds.Tables.Add();
    dt.Columns.Add("key", typeof(int));
    dt.Columns.Add("name", typeof(string));

    dt.Rows.Add(0, "Donald");
    dt.Rows.Add(0, "Duck");
    dt.Rows.Add(1, "Mickey");
    dt.Rows.Add(1, "Mouse");

    HttpRuntime.Cache.Insert("myCache", ds, null, Cache.NoAbsoluteExpiration,
                              Cache.NoSlidingExpiration, CacheItemPriority.High, null);
}

public DataSet GetXMLData()
{
    if (HttpRuntime.Cache["myCache"] == null)
    {
        LoadCache();
    }
    return (DataSet)HttpRuntime.Cache["myCache"];
}

public void GetData()
{
    DataView dv = GetXMLData().Tables[0].DefaultView;
    dv.RowFilter = "key=0";
    DataTable dtTemp = dv.ToTable();
    dtTemp.Columns.Add("sort");
}

private void SomeFunction()
{
    // Call GetData several times.
    GetData();
    GetData();
    GetData();
}

由于我不知道数据集的结构，我不能做更多的测试。

还有其他差异可能是一个因素。

As I don't know the structure of your dataset, I cannot do much more testing.
There are also other differences that might be a factor.

set



HttpRuntime.Cache [myCache添加一列后，] = null;



。

set

HttpRuntime.Cache["myCache"] = null;

after adding a column.

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