帮助:messbox无法正常显示 [英] Help:messbox can not show normally

问题描述

直到我按下键盘上的"Alt"键，messbox才能显示，我对此感到困惑，
详细信息是:
我在"MainForm"中运行该程序，然后打开另一个窗体，当我需要显示消息框时，它根本无法工作，除非我按"Alt"键?有什么问题?请帮助，谢谢
只需粘贴信息框代码:

messbox can not show until i press the "Alt" on the keyboard,i am confused that,
the detail is:
i run the program in "MainForm",then i open the other form ,when i need the messbox to show,it just can not work ,unless i press the "Alt" key? what''s problem?please help,thanks
just paste the messbox code:

//only show when press "Alt"
                MessageBox.Show(str, "the result is:");

实际上，我曾经遇到过这个问题，当我用Mainform打开子表单时，我发现它有时会消失，我搜索google，只是在MFC中发现了类似的问题，还有，我想知道这个问题是只是消息框未显示在frontform上，因为我调试了该代码行并确保已执行，但未显示.

in fact,i once met that problem ,and i found that it sometimes apears when i opend the subform with the Mainform ,i search the google , just found the similar problem in MFC ,and what''s more ,i wonder this problem is just the messagebox not show on frontform,because i debug that code line and sure it is executed,but not show .

推荐答案

    private void menuBeginClass_Click(object sender, EventArgs e)
    {
    if (strConnect != "")
        {
        /*
    *This program is just something like Pictue Recognition
    */
            ClassMethod cmForm = new ClassMethod();
            cmForm.ShowDialog();
            bool nearChose = cmForm.GetMethod();
            int nearSize = cmForm.GetLength();
            int midPixel = (int)((nearSize - 1) / 2);

            strCommandtext = "select * from Sign";
            myConnect = new OleDbConnection(strConnect);

            DataRow myDataRow = null;
            DataTable mydataTable = new DataTable();
            mydataAdapter = new OleDbDataAdapter(strCommandtext, myConnect);
            mydataAdapter.Fill(mydataTable);
            myDataRow = mydataTable.NewRow();
            myCommBuilder = new OleDbCommandBuilder(mydataAdapter);

            try
            {
                //MessageBox.Show("Connect db sucess");
                myConnect.Open();
                ClassNum = mydataTable.Rows.Count;

                if (ClassNum > 0)
                {
                    for (int i = 0; i < mydataTable.Rows.Count; i++)
                    {
                        strRecord[i] = mydataTable.Rows[i]["ClassName"].ToString ();
                      record[i, 0] = Convert.ToInt32(mydataTable.Rows[i]["ColorR"]);
                      record[i, 1] = Convert.ToInt32(mydataTable.Rows[i]["ColorG"]);
                      record[i, 2] = Convert.ToInt32(mydataTable.Rows[i]["ColorB"]);
                 record[i, 3] =Convert.ToInt32(mydataTable.Rows[i]["redThreshold"]);
              record[i, 4] = Convert.ToInt32(mydataTable.Rows[i]["greenThreshold"]);
               record[i, 5] = Convert.ToInt32(mydataTable.Rows[i]["blueThreshold"]);
                    }
                }

                Bitmap dstBmp = countSign(record,midPixel,nearChose);

                string str = "Classify finish!:" + "\t\n";
                for (int i = 0; i < ClassNum; i++)
                {
                    str += strRecord[i] + ": " + countClass[i].ToString() + "\t\n";
                }
                /*
                 *Here is the problem,only show when press "Alt"
        */
        MessageBox.Show(str,"the result is:");

                saveFileDialog1.Filter = "JPeg Image|*.jpg|Bitmap Image|*.bmp|Tif Image|*.tif";
                saveFileDialog1.Title = "Save an Image File";
                saveFileDialog1.ShowDialog();

                // If the file name is not an empty string open it for saving.
                if (saveFileDialog1.FileName != "")
                {
                    string FileName = saveFileDialog1.FileName;
                    switch (saveFileDialog1.FilterIndex)
                    {
                        case 0:
                            dstBmp.Save(FileName, ImageFormat.Jpeg);
                            break;
                        case 1:
                            dstBmp.Save(FileName, ImageFormat.Bmp );
                            break;
                        case 2:
                            dstBmp.Save(FileName, ImageFormat.Tiff) ;
                            break;
                        default :
                            dstBmp.Save(FileName, ImageFormat.Jpeg);
                            break;
                    }
                }

            }
            catch (OleDbException exp)
            {
                MessageBox.Show(exp.ToString());
                Application.Exit();
            }
            finally
            {
                //close connect
                myConnect.Close();
                myConnect.Dispose();
                myCommBuilder.Dispose();

                if (mydataAdapter != null)
                    mydataAdapter.Dispose();
            }
        }
}

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