从 OpenFileDialog 处理多个选定的文件

Question

我使用 foreach 循环读取多个图像文件，但我只能流式传输第一个选择的 file.When 我尝试保存多个不同的图像，输出就像第一个选择的图像的精确副本，而不是保持不同图片。

    private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(DBHandler.GetConnectionString());
        try
        {
            OpenFileDialog fop = new OpenFileDialog();
            fop.Multiselect = true;

            fop.InitialDirectory = "C:\";
            fop.Filter = "JPG,JPEG|*.jpg|PNG|*png";
            if (fop.ShowDialog() == DialogResult.OK)
            {

                foreach (String files in fop.FileNames)
                {
                    FileStream FS = new FileStream(@fop.FileName, FileMode.Open, FileAccess.Read);
                    byte[] img = new byte[FS.Length];
                    FS.Read(img, 0, Convert.ToInt32(FS.Length));

                    if (con.State == ConnectionState.Closed)
                        con.Open();
                    SqlCommand cmd = new SqlCommand("SaveImage", con);
                    cmd.CommandType = CommandType.StoredProcedure;
                    cmd.Parameters.Add("@img", SqlDbType.Image).Value = img;
                    cmd.ExecuteNonQuery();

                }

                MessageBox.Show("Image has been saved successfully!!", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }

我想在同一张表格上查看所有图片。

我的期望：A-B-C-D （每个字母代表不同的检索图像。"A"是从对话框中选择的第一个文件）

实际输出：A-A-A-A。为什么会这样？

Answer 1

在您的循环中，您正在使用 fop.FileName，其中 returns 第一个选择的文件：

This property can only be the name of one selected file. If you want to return an array containing the names of all selected files in a multiple-selection dialog box, use FileNames.

foreach (String files in fop.FileNames)
{
    FileStream FS = new FileStream(@fop.FileName, FileMode.Open, FileAccess.Read);

    // ...
}

改为使用迭代变量 filename:

foreach (String filename in fop.FileNames)
{
    FileStream FS = new FileStream(filename, FileMode.Open, FileAccess.Read);

    // ...
}

相关：.

Answer 2

你的代码应该是这样的

private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(DBHandler.GetConnectionString());
        try
        {
            OpenFileDialog fop = new OpenFileDialog();
            fop.Multiselect = true;

            fop.InitialDirectory = @"C:\";
            fop.Filter = "JPG,JPEG|*.jpg|PNG|*png";
            if (fop.ShowDialog() == DialogResult.OK)
            {

                foreach (String files in fop.FileNames)
                {
                    FileStream FS = new FileStream(@files, FileMode.Open, FileAccess.Read);
                    byte[] img = new byte[FS.Length];
                    FS.Read(img, 0, Convert.ToInt32(FS.Length));

                    if (con.State == ConnectionState.Closed)
                        con.Open();
                    SqlCommand cmd = new SqlCommand("SaveImage", con);
                    cmd.CommandType = CommandType.StoredProcedure;
                    cmd.Parameters.Add("@img", SqlDbType.Image).Value = img;
                    cmd.ExecuteNonQuery();

                }

                MessageBox.Show("Image has been saved successfully!!", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }

从 OpenFileDialog 处理多个选定的文件

Process multiple selected files from OpenFileDialog

c#

sql-server

filestream