Applying a filter to a BindingSource, but it doesn't work

Question

I have a TextBox, in which I put a phrase, which is either the description of a task or the id of a task. I want to filter a list using the text from this TextBox. But when I put text into this TextBox, filtering doesn't work, and the collection in the DataGridView doesn't change.

What can be wrong?

public void BindData()
{
    var emptyBindingSource = new BindingSource();
    dataGridViewTaskList.AutoGenerateColumns = false;
    dataGridViewTaskList.DataSource = emptyBindingSource;

    var taskList = GetTasks();

    _bindingSource = new BindingSource();
    _bindingSource.DataSource=taskList.Response;

    dataGridViewTaskList.AutoGenerateColumns = false;

    dataGridViewTaskList.DataSource = _bindingSource.DataSource;

    if (dataGridViewTaskList.Columns["gridViewColumnId"] == null)
        dataGridViewTaskList.Columns.Add(new DataGridViewColumn() {Name = "gridViewColumnId"});
    else
        dataGridViewTaskList.Columns["gridViewColumnId"].DataPropertyName = "Id";

    if (dataGridViewTaskList.Columns["gridViewColumnDescription"] == null)
        dataGridViewTaskList.Columns.Add(new DataGridViewColumn() {Name = "gridViewColumnDescription"});
    else
        dataGridViewTaskList.Columns["gridViewColumnDescription"].DataPropertyName = "Description";
}

private void tbSearchedPhraseOrId_TextChanged(object sender, EventArgs e)
{
    _bindingSource.Filter = string.Format("Id = '{0}'", tbSearchedPhraseOrId.Text);
}

I added the following in BindData method and it doesn't work either:

_bindingSource.Filter = string.Format("Id LIKE '%{0}%'", "23");

Designer:

this.dataGridViewTaskList.AllowUserToAddRows = false;
this.dataGridViewTaskList.AllowUserToDeleteRows = false;
this.dataGridViewTaskList.AllowUserToOrderColumns = true;
this.dataGridViewTaskList.AllowUserToResizeRows = false;
this.dataGridViewTaskList.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
                        | System.Windows.Forms.AnchorStyles.Left)
                        | System.Windows.Forms.AnchorStyles.Right)));
this.dataGridViewTaskList.AutoSizeColumnsMode = System.Windows.Forms.DataGridViewAutoSizeColumnsMode.Fill;
this.dataGridViewTaskList.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
this.dataGridViewTaskList.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
this.dataGridViewTaskList.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] {
this.gridViewColumnId,
this.gridViewColumnDescription});
this.dataGridViewTaskList.Location = new System.Drawing.Point(6, 62);
this.dataGridViewTaskList.MultiSelect = false;
this.dataGridViewTaskList.Name = "dataGridViewTaskList";
this.dataGridViewTaskList.ReadOnly = true;
this.dataGridViewTaskList.RowHeadersVisible = false;
this.dataGridViewTaskList.SelectionMode = System.Windows.Forms.DataGridViewSelectionMode.FullRowSelect;
this.dataGridViewTaskList.Size = new System.Drawing.Size(414, 488);
this.dataGridViewTaskList.TabIndex = 0;

Answer 1

According to the documentation, your underlying data source (i.e. your task list) must implement the IBindingListView interface to have a working Filter property. Are you sure this is the case right now?

(As an aside, you should set the DataSource property of your DataGridView to the BindingSource object itself rather than the BindingSource.DataSource property.)

Answer 2

You can always check _bindingSource.SupportsFiltering to see if the BindingSource type supports filtering