我DataGridView通過(guò)運(yùn)行 SQL 查詢來(lái)填充BackgroundWorker. 如果我直接在按鈕事件處理程序中運(yùn)行代碼，我的代碼將完美運(yùn)行，但是當(dāng)我放入DoWorkBackgroundWorker 時(shí)，它不會(huì)更新 UI。我的代碼如下。DataTable tab1table = new DataTable();public Form1(){ InitializeComponent(); Instantiatesearch1Thread();}private void Instantiatesearch1Thread(){ search1Thread.WorkerReportsProgress = true; search1Thread.WorkerSupportsCancellation = true; search1Thread.ProgressChanged += search1Thread_ProgressChanged; search1Thread.DoWork += search1Thread_Dowrk; search1Thread.RunWorkerCompleted += search1Thread_RunWorkerCompleted;} private void sbutton1_Click(object sender, EventArgs e){ search1Thread.RunWorkerAsync();}void search1Thread_Dowrk(object sender, DoWorkEventArgs e){ int percentprogress = 0; percentprogress++; Thread.Sleep(1000); // Search1 button event handler using (SqlConnection conn = new SqlConnection(connectionstring)) { conn.Open(); using (SqlDataAdapter cmd = new SqlDataAdapter(comboBox1SQL, conn)) { if (comboBox1.Text.Contains("ID")) { long para = long.Parse(search1.Text); cmd.SelectCommand.Parameters.Add(new SqlParameter { ParameterName = "@combo1Par", Value = para, SqlDbType = SqlDbType.BigInt }); }通過(guò)使用 aMessageBox我發(fā)現(xiàn)代碼沒(méi)有訪問(wèn)if comboBox1.Text.Contains()語(yǔ)句，我認(rèn)為這是有道理的，因?yàn)樵撔畔?lái)自 UI 并且BackgroundWorker不能直接訪問(wèn) UI。這也可以解釋為什么當(dāng)時(shí)tab1datatable并tab1table沒(méi)有受到影響。我想我需要在Invoke某處使用該方法，但我不確定如何使用。我查看了c# - 在執(zhí)行期間將信息從 UI 傳遞給 BackgroundWorker，但它并沒(méi)有真正回答我的問(wèn)題。如果Invoke是我需要的，我如何在此代碼中實(shí)現(xiàn)以允許它從 UI 獲取信息并隨后用填充的更新它DataGridView？
2 回答
慕尼黑5688855
TA貢獻(xiàn)1848條經(jīng)驗(yàn) 獲得超2個(gè)贊
這是您需要做的：
private string search1_Text = "";
private string comboBox1_Text = "";
private void Instantiatesearch1Thread()
{
search1_Text = search1.Text;
comboBox1_Text = comboBox1.Text;
search1Thread.WorkerReportsProgress = true;
search1Thread.WorkerSupportsCancellation = true;
search1Thread.ProgressChanged += search1Thread_ProgressChanged;
search1Thread.DoWork += search1Thread_Dowrk;
search1Thread.RunWorkerCompleted += search1Thread_RunWorkerCompleted;
}
在運(yùn)行后臺(tái)工作程序之前，您基本上獲取了所需數(shù)據(jù)的副本。
然后您只需訪問(wèn)DoWork代碼中的字段：
void search1Thread_Dowrk(object sender, DoWorkEventArgs e)
{
int percentprogress = 0;
percentprogress++;
Thread.Sleep(1000);
// Search1 button event handler
using (SqlConnection conn = new SqlConnection(connectionstring))
{
conn.Open();
using (SqlDataAdapter cmd = new SqlDataAdapter(comboBox1SQL, conn))
{
if (comboBox1_Text.Contains("ID"))
{
long para = long.Parse(search1_Text);
cmd.SelectCommand.Parameters.Add(new SqlParameter
{
ParameterName = "@combo1Par",
Value = para,
SqlDbType = SqlDbType.BigInt
});
}
else if (comboBox1_Text.Contains("Other Thing") || comboBox1_Text.Contains("Other Stuff"))
{
string para = search1_Text;
cmd.SelectCommand.Parameters.Add(new SqlParameter
{
ParameterName = "@combo1Par",
Value = "%" + para + "%",
SqlDbType = SqlDbType.NVarChar,
});
}
// Clear datatable if it contains any information and then fill it
// tab1datatable is a DataGridView
if (tab1table != null)
tab1table.Clear();
cmd.Fill(tab1table);
//tab1datatable.DataSource = tab1table;
// A bunch of expensive calculations
}
}
}
慕妹3146593
TA貢獻(xiàn)1820條經(jīng)驗(yàn) 獲得超9個(gè)贊
我不確定這是否是一個(gè)好的解決方案，但這可行。CheckForIllegalCrossThreadCalls初始化時(shí)設(shè)置為 false BackgroundWorker。
private void Instantiatesearch1Thread()
{
// Initialize other stuff
CheckForIllegalCrossThreadCalls = false;
}
并在任務(wù)完成后將其設(shè)置為 false。
private void search1Thread_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
// Do your work,
CheckForIllegalCrossThreadCalls = true;
}
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