Question

我的图像插入事件有问题。图像数据类型是blob。问题领域是：

"byte[] ImageBytes = (byte[])SelectedRowValue.Row.ItemArray[0];"

错误消息说：

"Unable to cast object of type 'System.Int32' to type 'System.Byte[]'."

下面是我的xaml，c＃和sql代码。它们被删节并简化了我真实项目的一部分：

XAML项目只包含一个按钮和一个数据网格

<Window x:Class="PupilReg.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Binding To Ado.net" Height="644.351" Width="674.234" FontSize="15" FontWeight="Bold" ResizeMode="CanResizeWithGrip">
<Grid>
    <DataGrid  Name="dataGrid1" Height="565" Width="435" AutoGenerateColumns="False" Margin="188,10,43,38">
        <DataGrid.ItemBindingGroup>
            <BindingGroup/>
        </DataGrid.ItemBindingGroup>
        <DataGrid.Columns>
            <DataGridTextColumn Header="Image_ID" Binding="{Binding Path=Image_ID}"  Width="80"/>
           <DataGridTemplateColumn Header="Image_BLOB" Width="200" IsReadOnly="True">
                <DataGridTemplateColumn.CellTemplate>
                    <DataTemplate>
                        <Image Source="{Binding Path=Image_BLOB}" Width="160" Height="160" />
                    </DataTemplate>
                </DataGridTemplateColumn.CellTemplate>
            </DataGridTemplateColumn>
        </DataGrid.Columns>
    </DataGrid>
    <Button x:Name="InsertImage" Content="Insert" Click="InsertImage_Click" Margin="31,39,583,541"/>
</Grid>

C＃

namespace PupilReg
{    
    public partial class MainWindow : Window
    {
         string constr = "Data Source=localhost;port=3306;Initial     Catalog=test;User Id=root;password=2525";
        public MainWindow()
        {
            InitializeComponent();
            BindGrid1();
        }

        private void BindGrid1()
        {
            MySqlConnection con = new MySqlConnection(constr);
            MySqlCommand cmd = new MySqlCommand("SELECT * FROM images",     con);
            MySqlDataAdapter da = new MySqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            da.Fill(dt);
            dataGrid1.ItemsSource = dt.DefaultView;

        }
        private void InsertImage_Click(object sender, RoutedEventArgs e)
        {
            {
                DataRowView SelectedRowValue =     (DataRowView)dataGrid1.SelectedValue;
                byte[] ImageBytes = (byte    [])SelectedRowValue.Row.ItemArray[0];
                MySqlConnection objConnection = new MySqlConnection    (constr);
                string CommandText = "INSERT INTO images (Image) VALUES     (@ImageSource)";
                MySqlCommand objCommand = new MySqlCommand(CommandText,     objConnection);
                objCommand.Parameters.Add("@ImageSource",     MySqlDbType.Blob, ImageBytes.Length).Value = ImageBytes;
                objConnection.Open();
                objCommand.ExecuteNonQuery();
                objConnection.Close();
            }
        }
    }
}

SQL

CREATE TABLE `images` 
(
`Image_ID` int(32) NOT NULL AUTO_INCREMENT,
`Image_BLOB` blob,
PRIMARY KEY (`Image_ID`)
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=binary;

将所选图像从datagrid（wpf）插入到mysql表中

0 个答案: