过滤 BindingSource 和 DataGridView答案

【问题标题】：Filtering BindingSource and DataGridView过滤 BindingSource 和 DataGridView
【发布时间】：2018-05-13 14:33:09
【问题描述】：

当我的 DataSource 是 BindingSource 时，我试图过滤我的 DataGridView。当我尝试更改 BindingSource 中的过滤器时，只有 BindingSource.Filter 值发生变化，但 DGV 看起来仍然相同。如何完成过滤我的 DGV？

BindingSource udalosti = new BindingSource();
//filling bindingsource by udalosti.Add()
eventDataGridView.DataSource = udalosti;

这是我的过滤功能

string filter="";
if (typeComboBox.Text != "")
{
    filter = "Typ LIKE '" + typeComboBox.Text + "' AND ";
}
if (descriptionTextBox.Text != "")
{ 
    filter += "Popis LIKE '%" + descriptionTextBox.Text + "%' AND ";
}
if (sourceTextBox.Text != "")
{
    filter += "Zdroj LIKE '" + sourceTextBox.Text + "' AND ";
}
if (filter.Length > 0)
    udalosti.Filter = filter.Substring(0, filter.Length - 5);
else
    udalosti.Filter = filter;
eventDataGridView.ResetBindings();

这就是内容的样子

class Udalost
{
   public string Typ { get; set; }
   public string Popis { get; set; }
   public string Zdroj { get; set; }
   public DateTime Cas { get; set; }
}

【问题讨论】：

您的数据源是否支持 IBindingListView？如果没有，它就不能从 BindingSource 的过滤器功能中受益。
文档说是msdn.microsoft.com/cs-cz/library/…
@HynekBernard 不，它说它没有。 BindingSource.Filter Property - 备注摘录：“只有实现IBindingListView 接口的底层列表才支持过滤。”

标签： c# .net datagridview datasource

【解决方案1】：

使用DataTable 是最简单的方法，因此您不必实现IBindingListView。

CS：

public partial class Form1 : Form
{
    MyDataTable dt;
    BindingSource bs;

    public Form1()
    {
        InitializeComponent();

        dt = new MyDataTable();
        bs = new BindingSource();
        bs.DataSource = dt.DefaultView;
        dataGridView1.DataSource = bs;
    }

    private void buttonAdd_Click(object sender, EventArgs e)
    {
        var r = new Random();
        var dr = dt.NewRow();
        dr[0] = r.Next(1111, 9999);
        dr[1] = r.Next(1111, 9999);
        dr[2] = r.Next(1111, 9999);
        dt.Rows.InsertAt(dr, 0);
    }

    private void buttonRemove_Click(object sender, EventArgs e)
    {
        dt.Rows.RemoveAt(0);
    }

    private void buttonClear_Click(object sender, EventArgs e)
    {
        textBox1.Text =
        textBox2.Text =
        textBox3.Text = string.Empty;
        UpdateDgv();
    }

    private void textBox1_TextChanged(object sender, EventArgs e)
    {
        UpdateDgv();
    }

    private void textBox2_TextChanged(object sender, EventArgs e)
    {
        UpdateDgv();
    }

    private void textBox3_TextChanged(object sender, EventArgs e)
    {
        UpdateDgv();
    }

    private void UpdateDgv()
    {
        string filter = GetFilter();

        if (filter != string.Empty)
            this.Text = filter;
        else this.Text = "All records";

        bs.Filter = filter;
    }

    private string GetFilter()
    {
        string filter = string.Empty;

        if (textBox1.Text != string.Empty)
            filter = string.Format("Data1 like '{0}%'", textBox1.Text);

        if (textBox2.Text != string.Empty)
        {
            if (textBox1.Text != string.Empty)
                filter += " and ";
            filter += string.Format("Data2 like '{0}%'", textBox2.Text);
        }

        if (textBox3.Text != string.Empty)
        {
            if (filter != string.Empty)
                filter += " and ";
            filter += string.Format("Data3 like '{0}%'", textBox3.Text);
        }

        return filter;
    }
}

数据表：

public class MyDataTable : DataTable
{
    public MyDataTable()
    {
        Columns.Add("Data1", typeof(string));
        Columns.Add("Data2", typeof(string));
        Columns.Add("Data3", typeof(string));

        DataRow dr;
        var r = new Random();
        for (int i = 0; i < 1000; i++)
        {
            dr = NewRow();
            dr["Data1"] = r.Next(1111, 9999);
            dr["Data2"] = r.Next(1111, 9999);
            dr["Data3"] = r.Next(1111, 9999);
            Rows.Add(dr);
        }
    }
}

【讨论】：