迭代DataTable.DataColumns非常慢 [英] Iterating DataTable.DataColumns very slow

问题描述

我已经搜索了问题，并为此搜索了google，但找不到任何东西.我创建了一个使用自定义GridView的C#.NET Forms应用程序.在此GridView中，我读取了自定义过滤器的所有列名称.我使用以下代码执行此操作:

Hi,

I''ve searched the questions and google for this but couldn''t find anything. I have created a C# .NET Forms application that uses a custom GridView. In this GridView I read all column names for a custom filter. I do this with this code:

// _AllData = DataTable
// _FilterColumns = List<filtercolumnclass>

int index = 0;

foreach (DataColumn col in _AllData.Columns)
{
    bool found = false;

    foreach (FilterColumnClass filter in _FilterColumns)
    {
        if (filter.ColumnName == col.ColumnName)
        {
            found = true;
            filter.Index = index;
        }
    }

    if (!found)
    {
        FilterColumnClass new_filter = new FilterColumnClass();
        new_filter.ColumnName = col.ColumnName;
        new_filter.Index = index;
        new_filter.FilterCheckControl.eventAskCurrentDataTable += new AskDataTableByInt(FilterCheckControl_eventAskCurrentDataTable);
        new_filter.FilterCheckControl.eventAskSourceDataTable += new AskDataTableByInt(FilterCheckControl_eventAskSourceDataTable);
        new_filter.FilterCheckControl.eventApplyFilter += new EventHandler(FilterCheckControl_eventApplyFilter);
        _FilterColumns.Add(new_filter);
        this.Controls.Add(new_filter.FilterCheckControl);
    }

    index++;
}
</filtercolumnclass>

它可以工作，但是非常慢，一个具有约80列的数据表将需要大约200毫秒的迭代时间.所以我的问题是，我该如何加快速度?

It works, but it''s very slow, a datatable with about 80 columns will take about 200 ms to iterate. So my question is, how can I speed this up?

推荐答案

尝试SuspendLayout可以加快速度. (添加了一些额外的代码，有望加快该过程)

Try SuspendLayout to speed it up. (Added some extra code that hopefully speeds up the process)

this.SuspendLayout();
try
 foreach (DataColumn col in _AllData.Columns)
 {
    FilterColumnClass fc = _FilterColumns.Find(delegate(FilterColumnClass item) { return item.ColumnName == col.ColumnName; });
    
    if (fc != null)    
    {
        filter.Index = index;
    }
    {
        FilterColumnClass new_filter = new FilterColumnClass();   
        // ... 
    }
} finally
{
  this.ResumeLayout();
}

祝你好运！

Good luck!

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