c＃winform调用引发NullReferenceException
|
我正在开发winform（mdi）专业版。当我从另一个线程获取新数据时，我需要更新dataGridView控件。当新数据到来并且我拖动dataGridview滚动时，它将在dataGridView.Invoke中引发nullreference异常。我搜索了几天，让Google疯狂，但没有帮助。
像这样的代码：
public void ReceiveNewData(object sender, UpateEventArgs ex)
{
if (this.dataGridView.InvokeRequired)
{
dataGridView.Invoke(new UpateEventHandler(ReceiveNewData), new object[] { this, ex });
}
else
this.BindNewData();
}
private void BindNewData()
{
if (dataGridView!= null && (QuoteMember.listOneClickQuoteItem != null || QuoteMember.listMarketingQuoteItem != null))
{
DataTable dataSource = PublicFunction.ToDataTable(QuoteMember.listOneClickQuoteItem);
if (dataSource != null)
dataSource.Merge(PublicFunction.ToDataTable(QuoteMember.listMarketingQuoteItem), true);
else
dataSource = PublicFunction.ToDataTable(QuoteMember.listMarketingQuoteItem);
dataGridView.DataSource = dataSource;
}
}
public PublicFunction
{
public static DataTable ToDataTable(List dataSource)
{
if(dataSource != null)
return ToDataTable((dataSource.ToArray()), 1);
return null;
}
public static DataTable ToDataTable(List dataSource)
{
if (dataSource != null)
return ToDataTable((dataSource.ToArray()), 2);
return null;
}
private static DataTable ToDataTable(QuoteItemBase[] m, int type)
{
DataTable dsTemp = null;
if (type == 1)
{
dsTemp = new DataTable(\"OneClickQuote\");
}
else if (type == 2)
{
dsTemp = new DataTable(\"MarketingQuote\");
}
else
dsTemp = new DataTable(\"temptable\");
dsTemp.Columns.Add(\"Date\");
dsTemp.Columns.Add(\"Time\");
dsTemp.Columns.Add(\"NO\");
dsTemp.Columns.Add(\"Name\");
if (m == null)
return dsTemp;
foreach (var item in m)
{
DataRow drTemp = dsTemp.NewRow();
drTemp[\"Date\"] = item.date;
drTemp[\"Time\"] = item.time;
drTemp[\"NO\"] = item.no;
drTemp[\"Name\"] = item.name;
dsTemp.Rows.Add(drTemp);
}
return dsTemp;
}
}
没有找到相关结果
已邀请:
2 个回复
babsoft
public class test : Form { public test() { Thread t = new Thread(start); t.Start(); } public void start() { LoadCompleteEvent(); } public void LoadComplete() //fired by LoadCompleteEvent(); { if(this.InvokeIsRequired) { //do invoke //and return } comboBoxEditBrand.Properties.Items.Clear(); comboBoxEditBrand.Properties.Items.AddRange(ListOfStuff.ToArray()); } public void comboBoxEditBrand_SelectedItemChanged(object sender, eventargs e) // fired as control is changed { //error here!! if(comboBoxEditBrand.SelectedItem == SomeBrandItem) //<- this is where the error is thrown!! check for null first! { //do something } } }//这里的错误！它应该可以再次工作。棠媳鳖