如何使用treeview过滤datagridview [英] How to use treeview to filter datagridview

问题描述

我正在尝试使用treeviews来过滤datagridview。这意味着要动态过滤。



到目前为止我有什么：



1.带有记录和三个树视图工具的数据网格视图[treeview1 ，treeview2&treeview3]

2.过滤datagridview记录的三种方法[我的代码]

3.点击事件后我的三个树视图[我的代码]

期望：想要像excel一样动态过滤：

I'm trying to use treeviews to filter datagridview.That means to filter dynamically.

What I have so far:

1. A datagridview with records and three treeview tool [treeview1, treeview2 & treeview3]
2. Three methods which filters the datagridview records [my code]
3. After click event for my three treeview [my code]
Expectation: Want to dynamic filter like excel:

推荐答案

我写了一个通用的rowFilter方法，后来在DataView级别应用了rowFilter方法。 />


感谢Maciej Los的帮助：

I wrote a generic rowFilter methode and later applied the rowFilter method at the DataView level.

Thanks to Maciej Los for the help:

// The method applies to all treeviews

foreach(TreeNode node in treeView1.Nodes) // Root treeview
            {
                if(node.Nodes.Count > 0)
                {
   // Iterate through the children nodes to start building the rowFilter string
                    foreach(TreeNode childNode in node.Nodes)
                    {
                        if (childNode.Checked)
                        {
                            if(treeview1.Length > 0)
                            {
                                treeview1RowFilter += " OR ";
                            }
                            treeview1RowFilter += "[AreaCode] = " + childNode.Text;
                        }
                        else if(childNode.Checked)
                        {
                            MessageBox.Show("Combobox is empty");
                        }
                    }
                }
            } 
// The same foreach loop for two remaining treeview
......
//  rowFilter strings that will have to concantenate 
 string rowFilter = string.Empty;

        if (cb11.Checked)
        {
            rowFilter += " [AreaCode] = " + cb11.Text.Trim();
        }
        if (cb16.Checked)
        {
            if (rowFilter.Length > 0)
                rowFilter += " OR";
            rowFilter += " [AreaCode] = " + cb16.Text.Trim();
        }
        if (cb31.Checked)
        {
            if (rowFilter.Length > 0)
                rowFilter += " OR";
            rowFilter += " [AreaCode] = " + cb31.Text.Trim();
        }

rowFilter = "(Grant='Yes') AND (AreaCode = 11 OR AreaCode = 31) AND (Land='North' OR Land='Schweiz')";

        try
        {
            //Check an see what's in the dgv
            DataView dv = new DataView(dt);
            dv.RowFilter = rowFilter;
            datagridview.Datasource = dv;
        }
        catch (Exception)
        {
            MessageBox.Show("Can’t find the column", "Info", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

调试程序并检查 rowFilter 返回的内容。似乎你错过了''围绕 childnote.Text 返回的文本。它应该类似于FieldName ='Some Text'





有关详细信息，请参阅：

DataView.RowFilter属性 [ ^ ]

DataView RowFilter语法[C＃] [ ^ ]





在这个论坛上有几次提到字符串是不可变的。该怎么办？请阅读：为什么字符串是不可变的，什么是它的含义是什么？ [ ^ ]





< a href =https://msdn.microsoft.com/en-us/library/system.data.dataview%28v=vs.110%29.aspx> DataView类 [ ^ ]启用过滤，但必须满足一些条件，请参阅： DataColumn.Expression [ ^ ]和排序和过滤数据 [ ^ ]



因此，根据您在评论中发布的图片，是或否值用于 Grant 列，然后

Debug your program and check what rowFilter returns. Seems you missed '' around the text returned by childnote.Text. It should be something like "FieldName = 'Some Text'"


For further information, please see:
DataView.RowFilter Property [^]
DataView RowFilter Syntax [C#][^]


Several time on this forum was mentioned that string is immutable. What to do? Please, read this: Why strings are immutable and what are the implications of it?[^]


DataView class[^] enables filtering, but some criteria must be fulfilled, see: DataColumn.Expression[^] and Sorting and Filtering Data[^]

So, based on the images you posted in comment, Yes or No value is used for Grant column, then

rowFilter = "Grant='Yes'";

如果你想添加几个条件，请使用：

If you want to add several condtions, use:

rowFilter = "(Grant='Yes') AND (AreaCode = 11 OR AreaCode = 31) AND (Land='North' OR Land='Schweiz')";

试试！

Try!

这篇关于如何使用treeview过滤datagridview的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！