DataGrid 行选择并打印其数据答案

【问题标题】：DataGrid row selection and printing its dataDataGrid 行选择并打印其数据
【发布时间】：2012-08-16 19:17:38
【问题描述】：

我的dataGrid中有一些行，当我选择其中一个并打印它的数据时，只会打印数据库的第一个图像而我只需要打印所选行的图像，这个sn-p在cmd.CommandText上有错误..., 我该如何改进它？

private void Print_Click(object sender, RoutedEventArgs e)
    {
        System.Windows.Controls.PrintDialog printDialog = new System.Windows.Controls.PrintDialog();
        if (printDialog.ShowDialog() == true)
        {                
            DrawingVisual dv = new DrawingVisual();
            var dc = dv.RenderOpen();

            SqlConnection con = new SqlConnection();
            con.ConnectionString = @"Data Source=.\SQLEXPRESS;AttachDbFilename=D:\Database\Data.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True";
            SqlCommand cmd = new SqlCommand();
            BitmapImage bmp = new BitmapImage();

            cmd.Connection = con;
            con.Open();

            cmd.CommandText = "Select Picture from Personnels where Name= " + grdPersonnel1.SelectedItem;

            bmp.CacheOption = BitmapCacheOption.OnLoad;
            bmp.BeginInit();
            bmp.StreamSource = new System.IO.MemoryStream((Byte[])cmd.ExecuteScalar());
            bmp.EndInit();
            dc.DrawImage(bmp, new Rect(140, 170, 150, 150));

            dc.DrawText(new FormattedText("Name:", CultureInfo.GetCultureInfo("en-us"), FlowDirection,
                 new Typeface(new System.Windows.Media.FontFamily("Courier New"), FontStyles.Normal, FontWeights.Bold,
                     FontStretches.Normal), 12, System.Windows.Media.Brushes.Black), new System.Windows.Point(700, 180));
            dc.DrawText(new FormattedText(txtName.Text, CultureInfo.GetCultureInfo("en-us"), FlowDirection,
                  new Typeface(new System.Windows.Media.FontFamily("Courier New"), FontStyles.Normal, FontWeights.Normal,
                      FontStretches.Normal), 11, System.Windows.Media.Brushes.Black), new System.Windows.Point(550, 180));


            dc.Close();

            printDialog.PrintVisual(dv, "Print");
        }

<Image VerticalAlignment="Center" HorizontalAlignment="Center" Stretch="Fill" Name="PictureBox"
                   Source="{Binding Picture}" DataContext="{Binding Path=SelectedItem, ElementName=grdPersonnel1}" Opacity="2">
</Image>

【问题讨论】：

标签： c# sql wpf

【解决方案1】：

我不知道 grdPersonel1 是什么类型的控件，但是您应该查看 SelectedItem 是否为字符串...如果不是，您可能需要 SelectedValue 或 SelectedItem.Text（在名称字段中包含您想要的字符串的东西)

【讨论】：

SelectedItem 或 SelectedValue 并且没有一个不显示 .Text

【解决方案2】：

我假设 grdPersonnel1 是您的 DataGrid，项目是网格属于 Personnel 类型，并且 Personnel 具有 Name 属性。如果这是正确的，试试这个：

cmd.CommandText = "Select Picture from Personnels where Name= " + (grdPersonnel1.SelectedItem as Personnel).Name;

【讨论】：

是的 grdPersonnel1 是我的 DataGrid，我使用了这个 sn-p 但出现错误：对象引用未设置为对象的实例。

【解决方案3】：

我解决了：

private void Print_Click(object sender, RoutedEventArgs e)
{
    System.Windows.Controls.PrintDialog printDialog = new System.Windows.Controls.PrintDialog();
    if (printDialog.ShowDialog() == true)
    {                
        DrawingVisual dv = new DrawingVisual();
        var dc = dv.RenderOpen();

         SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=D:\Database\Database.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True");
            SqlCommand cmd = new SqlCommand();

            BitmapImage bmp = new BitmapImage();
            cmd.CommandText = "Select Picture from Database where Code=@Code";
            cmd.Parameters.Add("@Code", SqlDbType.NVarChar, 30);
            cmd.Parameters["@Code"].Value = this.txtCode.Text;
            cmd.Connection = con;
            con.Open();

            bmp.CacheOption = BitmapCacheOption.OnLoad;
            bmp.BeginInit();
            bmp.StreamSource = new System.IO.MemoryStream((Byte[])cmd.ExecuteScalar());
            bmp.EndInit();
            dc.DrawImage(bmp, new Rect(140, 170, 150, 150));

        dc.DrawText(new FormattedText("Name:", CultureInfo.GetCultureInfo("en-us"), FlowDirection,
             new Typeface(new System.Windows.Media.FontFamily("Courier New"), FontStyles.Normal, FontWeights.Bold,
                 FontStretches.Normal), 12, System.Windows.Media.Brushes.Black), new System.Windows.Point(700, 180));
        dc.DrawText(new FormattedText(txtName.Text, CultureInfo.GetCultureInfo("en-us"), FlowDirection,
              new Typeface(new System.Windows.Media.FontFamily("Courier New"), FontStyles.Normal, FontWeights.Normal,
                  FontStretches.Normal), 11, System.Windows.Media.Brushes.Black), new System.Windows.Point(550, 180));


        dc.Close();

        printDialog.PrintVisual(dv, "Print");
    }

【讨论】：