Question

要批量上传许多文件，我有一段CSharp WPF代码，它产生了允许并行上传文件的线程。如果上载发生错误，将使用MessageBox弹出一条消息。这很好。

但是最近我们决定自定义MessageBox的外观。我发现当我们使用ShowDialog（）打开新的自定义WPF MessageBox窗口时，会抛出一个错误，指出无法启动GUI。这只发生在衍生线程的代码试图打开自定义消息窗口时 - 我从主线程打开自定义MessageBox时没有看到问题。

我的临时修复是捕获启动自定义对话框时发生的任何错误，或者调用标准MessageBox.Show（）来显示消息。这很有效。

我不确定为什么使用标准的MessageBox.Show（）是可以的，但它不适用于自定义窗口。有办法解决这个问题吗？

Answer 1

通常（在任何GUI-API中）不会从工作线程调用GUI函数，也不会在GUI线程上做大量工作。标准MessageBox在工作线程上工作的事实令人遗憾。

是的，你完全正确。当你的工作线程发生需要向用户显示的事件时，发送一个通知（信号，事件，无论你的框架调用它）到GUI线程并在那里显示消息。

Answer 2

protected void chkAll_CheckedChanged(object sender, EventArgs e)
    {
        CheckBox chall = (CheckBox)sender;
        for (int i = 0; i < GridView1.Rows.Count; i++)
        {
            CheckBox chSelect = (CheckBox)GridView1.Rows[i].FindControl("ChkSelect");
            if (chSelect != null)
            {
                chSelect.Checked = chall.Checked;
            }
        }
    }
    protected void chkSelect_CheckedChange(object sender, EventArgs e)
    {
        int i=0;
        CheckBox chkAll = (CheckBox)GridView1.HeaderRow.FindControl("chkAll");
        for ( i = 0; i < GridView1.Rows.Count; i++)
        {
            CheckBox chkSelect = (CheckBox)GridView1.Rows[i].FindControl("ChkSelect");
            if(chkSelect!=null && !chkSelect.Checked  )
                if (chkAll != null)
                {
                    chkAll.Checked = false;
                }
            break;
        }
        if (GridView1.Rows.Count == i && chkAll != null)
        {
            chkAll.Checked = true;
        }

    }
    protected void ddlPaymentMode_SelectedIndexChanged(object sender, EventArgs e)
    {
        DropDownList ddlpaymode = (DropDownList)sender;
        for (int i = 0; i < GridView1.Rows.Count; i++)
        {
            Label lblpaymode = (Label)GridView1.Rows[i].FindControl("lblPayAmt_Mode");
            CheckBox chpaymode = (CheckBox)GridView1.Rows[i].FindControl("ChkSelect");
            if (chpaymode.Checked)
            {
                lblpaymode.Text = ddlpaymode.SelectedItem.Text;
            }
        }
    }
    protected void ddlBankName_SelectedIndexChanged(object sender, EventArgs e)
    {
        DropDownList ddlBank = (DropDownList)sender;
        for (int i = 0; i < GridView1.Rows.Count; i++)
        {
            CheckBox cselect = (CheckBox)GridView1.Rows[i].FindControl("ChkSelect");
            Label lblBankName = (Label)GridView1.Rows[i].FindControl("LblBank");
            if (cselect.Checked)
            {
                lblBankName.Text = ddlBank.SelectedItem.Text;
            }

        }
    }
    protected void btnaddbpc_Click(object sender, EventArgs e)
    {
        int temp = Convert.ToInt32(txtChequeNo.Text);
        for (int i = 0; i < GridView1.Rows.Count; i++)
        {
            CheckBox chkselect = (CheckBox)GridView1.Rows[i].FindControl("ChkSelect");
            Label lblcheckno = (Label)GridView1.Rows[i].FindControl("LblCheque");


            if (chkselect.Checked)
            {

                lblcheckno.Text = Convert.ToString(temp);
                temp++; 
            }

        }
    }
    protected void dtnDelete_Click(object sender, EventArgs e)
    {
        for (int i = 0; i < GridView1.Rows.Count; i++)
        {
            CheckBox chkselect = (CheckBox)GridView1.Rows[i].FindControl("ChkSelect");
            Label lblcheckno = (Label)GridView1.Rows[i].FindControl("LblCheque");


            if (chkselect.Checked)
            {
                lblcheckno.Text = "";
            }

        }
    }
    protected void btnAddCDate_Click(object sender, EventArgs e)
    {
        for (int i = 0; i < GridView1.Rows.Count; i++)
        {
            Label lblchqdate = (Label)GridView1.Rows[i].FindControl("LblCheque_Date");
            CheckBox chkselect = (CheckBox)GridView1.Rows[i].FindControl("ChkSelect");
            if (chkselect.Checked)
            {
                lblchqdate.Text = TxtChequeDate.Text;
            }
        }
    }
    protected void btnRemovecDate_Click(object sender, EventArgs e)
    {
        for (int i = 0; i < GridView1.Rows.Count; i++)
        {
            Label lblchqdate = (Label)GridView1.Rows[i].FindControl("LblCheque_Date");
            CheckBox chkselect = (CheckBox)GridView1.Rows[i].FindControl("ChkSelect");
            if (chkselect.Checked)
            {
                lblchqdate.Text = "";
            }
        }
    }
    protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "Modify")
        {
            string ID = e.CommandArgument.ToString();
            //Response.Redirect("Admin_Update_BinryPayment.aspx?id="+ID+"&FromDate='"+ txtfromdate.Text +"'&ToDate='"+txttilldate.Text+"'");
            int Index = ((GridViewRow)((LinkButton)e.CommandSource).Parent.Parent).RowIndex;
            CheckBox chksec = (CheckBox)GridView1.Rows[Index].FindControl("ChkSelect");
            Label lblANo = (Label)GridView1.Rows[Index].FindControl("Label2");
            Label lbAName = (Label)GridView1.Rows[Index].FindControl("Label3");
            Label lbACName = (Label)GridView1.Rows[Index].FindControl("Label3");
            Label lbacNo = (Label)GridView1.Rows[Index].FindControl("lblBankAccountNo");
            Label lbBankName = (Label)GridView1.Rows[Index].FindControl("LblBank");
            Label lbchqNo = (Label)GridView1.Rows[Index].FindControl("LblCheque");
            Label lbchqDate = (Label)GridView1.Rows[Index].FindControl("LblCheque_Date");
            Label lblChqAmt = (Label)GridView1.Rows[Index].FindControl("Label23");
            if (chksec.Checked)
            {
                txtABNo.Text = GridView1.Rows[Index].Cells[3].Text;

Answer 3

        Dispatcher.BeginInvoke(DispatcherPriority.Background, (SendOrPostCallback)delegate {
            // show your MB here
        }, null);

从线程启动时，模态弹出窗口失败 - CSharp WPF

3 个答案: