为什么我的DataGridview拒绝刷新？ [英] Why does my DataGridview refuse to refresh?
问题描述
DataGridView.Invalidate（）和DataGridView.Refresh（），在更改可以看到之前，我必须关闭应用程序，重新启动并重新运行查询。 / p>
相关代码是：
private void buttonUpdate_Click（object sender， EventArgs e）
{
const int TICKETID_COLUMN = 0;
String _ticketID = dataGridView1.CurrentRow.Cells [SOME_COLUMN] .Value.ToString（）;
UpdateRecord（_ticketID，textBoxTicketSource.Text，
textBoxAboutSomeID.Text，textBoxCategoryID.Text，textBoxContactEmail.Text）;
private void UpdateRecord（string ATicketID，string ATicketSource，string
AAboutSomeID，string ACategoryID，string AContactID）
{
oracleConnection1.Open（） ;
OracleCommand ocmd = new OracleCommand（）;
OracleTransaction ot;
//启动本地事务
ot = oracleConnection1.BeginTransaction（System.Data.IsolationLevel.ReadCommitted）;
//为待处理的本地事务分配事务对象
ocmd.Transaction = ot;
ocmd.Connection = oracleConnection1;
尝试
{
ocmd.CommandText = @更新ABC.CONCERTTICKETS
SET TICKETSOURCE =：p_TICKETSOURCE，
ABOUTSOMEID =：p_ABOUTSOMEID，
CATEGORYID = p_CATEGORYID，
CONTACTEMAIL =：p_CONTACTEMAIL
WHERE TICKETID =：p_TICKETID;
ocmd.Parameters.Add（p_TICKETSOURCE，ATicketSource）;
ocmd.Parameters.Add（p_ABOUTSOMEID，Convert.ToInt32（AAboutSOMEID））;
ocmd.Parameters.Add（p_CATEGORYID，Convert.ToInt32（ACategoryID））;
ocmd.Parameters.Add（p_CONTACTEMAIL，AContactID）;
ocmd.Parameters.Add（p_TICKETID，ATicketID）;
ocmd.ExecuteNonQuery（）;
ot.Commit（）;
Popul8TheGrid（）;
dataGridView1.Invalidate（）;
dataGridView1.Refresh（）;
}
catch（异常e）
{
ot.Rollback（）;
throw;
}
finally
{
oracleConnection1.Close（）;
}
}
private void Popul8TheGrid（）
{
int iFromYear = dateTimePickerFrom.Value.Year;
int iFromMonth = dateTimePickerFrom.Value.Month;
int iFromDay = dateTimePickerFrom.Value.Day;
int iToYear = dateTimePickerTo.Value.Year;
int iToMonth = dateTimePickerTo.Value.Month;
int iToDay = dateTimePickerTo.Value.Day;
oracleCommand1.Parameters.Clear（）;
oracleCommand1.Parameters.Add（iStartDate，new DateTime（iFromYear，iFromMonth，
iFromDay））;
oracleCommand1.Parameters.Add（iEndDate，new DateTime（iToYear，iToMonth，
iToDay））;
oracleCommand1.Parameters.Add（iCATEGORYID，114）;
// OracleRef显然像OracleDbType.RefCursor;
OracleRef or = new OracleRef（_或）;
oracleCommand1.Parameters.Add（cref，或）;
oracleConnection1.Open（）;
oracleDataAdapter1.SelectCommand = oracleCommand1;
oracleDataAdapter1.GetFillParameters（）;
oracleDataAdapter1.Fill（oracleDataTable1）;
dataGridView1.DataSource = oracleDataTable1;
oracleConnection1.Close（）;
}
更新：
根据霍尔的建议（我试图回应一个评论，但似乎挂起）：
好的，我现在有了：
oracleDataAdapter1.SelectCommand = oracleCommand1;
oracleDataAdapter1.GetFillParameters（）;
oracleDataAdapter1.Fill（oracleDataTable1）;
//我没有看到一个清除方法或一些这样的...
dataGridView1.DataSource = null;
//dataGridView1.DataSource = oracleDataTable1;
BindingSource b = new BindingSource（）;
b.DataSource = oracleDataTable1;
dataGridView1.DataSource = b;
b.ResetBindings（false）;
oracleConnection1.Close（）;
...它仍然工作相同 - 更新，但DataGridView不知道，直到我重新启动了应用程序。
原因 Invalidate（） code> Refresh（）不要重新查询数据源，它们只适用于图形方面的事情 - 它们都会使控件的客户端区域无效，并强制重绘但是问题在于，底层控件认为数据源中没有任何变化，因为它依赖数据源来告诉它何时发生。
你需要的是您的 DataSource 将会告诉 DataGridView 发生了什么，例如 BindingList< ; T> 或 BindingSource ，两者都有 ListChanged 事件， code> DataGridView 订阅。
我以为 DataTable 通知网格改变时，我被误认为或$ code> OracleDataTable 是不同的。
应该解决的问题是引入一个 BindingSource ，并将其作为数据源为 DataGridView 。然后使您的 OracleDataTable 绑定源的数据源。如果这不工作，您可以在绑定源上调用 ResetBindings（）方法。
BindingSource b = new BindingSource（）;
b.DataSource = oracleDataTable1;
dataGridView1.DataSource = b;
I'm updating a row in a table. A subset of the table is shown in a DataGridView. When I update the row, the change is not reflected in the DataGridView. Even though I'm calling DataGridView.Invalidate() and DataGridView.Refresh() after committing the change, I have to shut down the app, restart, and re-run the query before the change can be seen.
The pertinent code is:
private void buttonUpdate_Click(object sender, EventArgs e)
{
const int TICKETID_COLUMN = 0;
String _ticketID = dataGridView1.CurrentRow.Cells[SOME_COLUMN].Value.ToString();
UpdateRecord(_ticketID, textBoxTicketSource.Text,
textBoxAboutSomeID.Text, textBoxCategoryID.Text, textBoxContactEmail.Text);
}
private void UpdateRecord(string ATicketID, string ATicketSource, string
AAboutSomeID, string ACategoryID, string AContactID)
{
oracleConnection1.Open();
OracleCommand ocmd = new OracleCommand();
OracleTransaction ot;
// Start a local transaction
ot = oracleConnection1.BeginTransaction(System.Data.IsolationLevel.ReadCommitted);
// Assign transaction object for a pending local transaction
ocmd.Transaction = ot;
ocmd.Connection = oracleConnection1;
try
{
ocmd.CommandText = @"UPDATE ABC.CONCERTTICKETS
SET TICKETSOURCE = :p_TICKETSOURCE,
ABOUTSOMEID = :p_ABOUTSOMEID,
CATEGORYID = :p_CATEGORYID,
CONTACTEMAIL = :p_CONTACTEMAIL
WHERE TICKETID = :p_TICKETID";
ocmd.Parameters.Add("p_TICKETSOURCE", ATicketSource);
ocmd.Parameters.Add("p_ABOUTSOMEID", Convert.ToInt32(AAboutSOMEID));
ocmd.Parameters.Add("p_CATEGORYID", Convert.ToInt32(ACategoryID));
ocmd.Parameters.Add("p_CONTACTEMAIL", AContactID);
ocmd.Parameters.Add("p_TICKETID", ATicketID);
ocmd.ExecuteNonQuery();
ot.Commit();
Popul8TheGrid();
dataGridView1.Invalidate();
dataGridView1.Refresh();
}
catch (Exception e)
{
ot.Rollback();
throw;
}
finally
{
oracleConnection1.Close();
}
}
private void Popul8TheGrid()
{
int iFromYear = dateTimePickerFrom.Value.Year;
int iFromMonth = dateTimePickerFrom.Value.Month;
int iFromDay = dateTimePickerFrom.Value.Day;
int iToYear = dateTimePickerTo.Value.Year;
int iToMonth = dateTimePickerTo.Value.Month;
int iToDay = dateTimePickerTo.Value.Day;
oracleCommand1.Parameters.Clear();
oracleCommand1.Parameters.Add("iStartDate", new DateTime(iFromYear, iFromMonth,
iFromDay));
oracleCommand1.Parameters.Add("iEndDate", new DateTime(iToYear, iToMonth,
iToDay));
oracleCommand1.Parameters.Add("iCATEGORYID", 114);
// OracleRef is apparently like OracleDbType.RefCursor;
OracleRef or = new OracleRef("_or");
oracleCommand1.Parameters.Add("cref", or);
oracleConnection1.Open();
oracleDataAdapter1.SelectCommand = oracleCommand1;
oracleDataAdapter1.GetFillParameters();
oracleDataAdapter1.Fill(oracleDataTable1);
dataGridView1.DataSource = oracleDataTable1;
oracleConnection1.Close();
}
Updated:
Based on Hall's suggestion (I tried to respond with a Comment, but it seems to be hung):
OK, I've got this now:
oracleDataAdapter1.SelectCommand = oracleCommand1;
oracleDataAdapter1.GetFillParameters();
oracleDataAdapter1.Fill(oracleDataTable1);
// I don't see a "Clear" method or some such...
dataGridView1.DataSource = null;
//dataGridView1.DataSource = oracleDataTable1;
BindingSource b = new BindingSource();
b.DataSource = oracleDataTable1;
dataGridView1.DataSource = b;
b.ResetBindings(false);
oracleConnection1.Close();
...and it still works the same - updates, but the DataGridView doesn't know it until I restart the app.
The reason Invalidate() and Refresh() don't requery the data source is that they are intended to only work with the graphical side of things - they both invalidate the client area of the control and force a repaint but the problem is that the underlying control thinks that nothing has changed in its data source since it relies upon the data source to tell it when that happens.
What you need is your DataSource to be something which will tell the DataGridView what is going on such as the BindingList<T> or a BindingSource, both of which have the ListChanged event which the DataGridView subscribes to.
I had thought the DataTable also informed the grid when it changed but I was either mistaken or the OracleDataTable is different.
What should fix the problem is introducing a BindingSource and making this the data source for the DataGridView. Then make your OracleDataTable the data source of the binding source. If this doesn't work you can then call the ResetBindings() method on the binding source.
BindingSource b = new BindingSource();
b.DataSource = oracleDataTable1;
dataGridView1.DataSource = b;
这篇关于为什么我的DataGridview拒绝刷新？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！
