Question

基本上，当我创建这个DataGridView时，我有这个代码来填充它

public void fillDataGrid(IQueryable<PatientInfo> patients) {

            dgvMyPatients.DataSource = patients;

            dgvMyPatients.Columns["Pat_Last_Name"].DisplayIndex = 0;
            dgvMyPatients.Columns["Pat_First_Name"].DisplayIndex = 1;
            dgvMyPatients.Columns["Pat_Middle_Name"].DisplayIndex = 2;
            dgvMyPatients.Columns["Pat_First_Name"].HeaderText = "First Name";
            dgvMyPatients.Columns["Pat_Last_Name"].HeaderText = "Last Name";
            dgvMyPatients.Columns["Pat_Middle_Name"].HeaderText = "Middle Name";

        }

public IQueryable<PatientInfo> showMyPatients() {

            DbClassesDataContext myDb = new DbClassesDataContext(dbPath);

            var patientInfo = from patients in myDb.PatientInfos
                              where patients.Phy_ID == physcianID
                              select patients;

            return patientInfo;
        }

因此，当我创建我的对象时，我就这样做了

fillDataGrid(showMyPatients());

但是当我点击一个按钮时，我想将其内容更改为此查询中的内容

 private IQueryable<PatientInfo> searchPatient() {

        DbClassesDataContext myDb = new DbClassesDataContext(dbPath);
        var search = from myPatients in myDb.PatientInfos
                     where (myPatients.Pat_ID == patient_ID && myPatients.Pat_First_Name.Contains(txtSearch.Text)) ||
                     (myPatients.Pat_ID == patient_ID && myPatients.Pat_Last_Name.Contains(txtSearch.Text)) ||
                    (myPatients.Pat_ID == patient_ID && myPatients.Pat_Middle_Name.Contains(txtSearch.Text))
                     select myPatients;

        return search;
    }

然后当我点击我的按钮它会这样做，但它没有更新数据网格为什么会这样？ fillDataGrid（searchPatient（））;

Answer 1

我有同样的问题，经过搜索和测试一段时间后，终于找到了解决方案：

a.First()

DataTable dt = new DataTable(); dt.Columns.Add("Column One"); dt.Rows.Add(new object[] { "Item1" }); dt.Rows.Add(new object[] { "Item2" }); dt.Rows.Add(new object[] { "Item3.3" }); this.dataGridView1.AutoGenerateColumns = true; this.dataGridView1.Columns.Clear(); //dataGridView1.DataSource = null; dataGridView1.DataSource = dt;需要AutoGenerateColumns，这就是它。

Answer 2

相反，如果做

DataSource = null

最好刷新货币经理，因为IQueryable返回CurrencyManager：

 (dgvMyPatients.BindingContext[dataGridView1.DataSource] as CurrencyManager).Refresh();

CurrencyManager

CurrencyManager.Refresh()

Answer 3

更改行：

dgvMyPatients.DataSource = patients;

到

dgvMyPatients.DataSource = typeof(List<>);
dgvMyPatients.DataSource = patients.ToList();

Answer 4

首先，您可以尝试设置：

DataSource = null;

在更新之前。我个人建议使用BindingList将数据绑定到dataGridView。这样，您不必更改dataSource - 仅包含其中包含的数据。它的使用方式如下：

BindingList<PatientInfo> data = new BindingList<PatientInfo>();
dgvMyPatients.DataSource = data;

...
public void fillDataGrid(IQueryable<PatientInfo> patients)
{
    data.Clear();
    data.AddRange(patients);
}

此外，每次更新源时都不需要提供datagrid架构。

<强>更新

工作样本：

public partial class Form1 : Form
{
    private BindingList<SomeClass> _data = new BindingList<SomeClass>();
    public Form1()
    {
        InitializeComponent();

        dataGridView1.DataSource = _data;
        _data.Add(new SomeClass() { First = "1", Second = "1", Third = "1" });
        _data.Add(new SomeClass() { First = "2", Second = "2", Third = "2" });
        _data.Add(new SomeClass() { First = "3", Second = "3", Third = "3" });
        _data.Add(new SomeClass() { First = "4", Second = "4", Third = "4" });
        _data.Add(new SomeClass() { First = "5", Second = "5", Third = "5" });
        _data.Add(new SomeClass() { First = "6", Second = "6", Third = "6" });
        _data.Add(new SomeClass() { First = "7", Second = "7", Third = "7" });
        _data.Add(new SomeClass() { First = "8", Second = "8", Third = "8" });
    }

    private void button1_Click(object sender, EventArgs e)
    {
        _data.Clear();
        _data.Add(new SomeClass() { First = "11", Second = "11", Third = "11" });
        _data.Add(new SomeClass() { First = "21", Second = "21", Third = "21" });
        _data.Add(new SomeClass() { First = "31", Second = "31", Third = "31" });
    }
}

public class SomeClass
{
    public string First { get; set; }
    public string Second { get; set; }
    public string Third { get; set; }
}

DataGridView动态更改数据源

4 个答案: