我们通常这么写
using (SqlDataReader drm = sqlComm.ExecuteReader())
{
drm.Read();//以下把数据库中读出的Image流在图片框中显示出来.
MemoryStream ms = new MemoryStream((byte[])drm["Logo"]);
Image img = Image.FromStream(ms);
this.pictureBox1.Image = img;
}
我的写数据
private void btnOK_Click(object sender, EventArgs e)
{
string name = "";
if (tbxUserName.Text.Trim() == "")
{
MessageBox.Show("姓名不能为空，请重新输入！", "提示");
return;
}
else
{
name = tbxUserName.Text.Trim();
}
string group = "";
if (cbxGroup.Text.Trim() == "")
{
group = "未分组";
}
else
{
group = cbxGroup.Text.Trim();
}
string phone = tbxTel.Text.Trim();
string workunit = tbxWorkUnit.Text.Trim();
string email = tbxEmail.Text.Trim();
string qq = tbxQQ.Text.Trim();
byte[] b = null;
if (txtFilePath != "")
{
try
{
FileStream fs = new FileStream(txtFilePath, FileMode.Open, FileAccess.Read);//类型为打开数据 权限为只读 不呢写数据
int length = Convert.ToInt32(fs.Length);
b = new byte[length];
fs.Read(b, 0, length);//数据读入b数组中 从0号到length位
fs.Close();//关闭输入输出流
}
catch (Exception ex)
{
b = null;
MessageBox.Show(ex.Message);
}
}
else
{
b = pixData;
}
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
//获取当前的数据在表中的ID
SqlCommand commandInsert = new SqlCommand();
commandInsert.Connection = connection;
//connection.Close();
connection.Open();
//插入数据
commandInsert.CommandText = "USE db_TXL UPDATE tb_BusicInfo set Groups= @Groups ,[email protected],[email protected],[email protected],[email protected],[email protected],[email protected]";
commandInsert.CommandText += " where [email protected] ";
commandInsert.Parameters.Add("@ID", SqlDbType.Int);
commandInsert.Parameters.Add("@Groups", SqlDbType.VarChar, 50);
commandInsert.Parameters.Add("@Name", SqlDbType.VarChar, 20);
commandInsert.Parameters.Add("@WorkUnit", SqlDbType.VarChar, 50);
commandInsert.Parameters.Add("@Phone", SqlDbType.VarChar, 14);
commandInsert.Parameters.Add("@Email", SqlDbType.VarChar, 50);
commandInsert.Parameters.Add("@QQ", SqlDbType.VarChar, 20);
commandInsert.Parameters.Add("@Picture", SqlDbType.Image);//Image的类型不能写错！！
commandInsert.Parameters["@ID"].Value = ID;
// commandInsert.Parameters["@UserName"].Value = strUserName;
commandInsert.Parameters["@Groups"].Value = group;
commandInsert.Parameters["@Name"].Value = name;
commandInsert.Parameters["@WorkUnit"].Value = workunit;
commandInsert.Parameters["@Phone"].Value = phone;
commandInsert.Parameters["@Email"].Value = email;
commandInsert.Parameters["@QQ"].Value = qq;
//commandInsert.Parameters[""].Value=;
if (txtFilePath == "" && pixData==null)
{
commandInsert.Parameters["@Picture"].Value = DBNull.Value;//DBNull 不存在的值NULL
}
else
{
commandInsert.Parameters["@Picture"].Value = b;
}
commandInsert.ExecuteNonQuery();
connection.Close();
DialogResult = DialogResult.OK;
}
}
catch (Exception ex) { MessageBox.Show(ex.Message); }
}
我的读数据
private void frmEdit_Load(object sender, EventArgs e)
{
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
string commandString = "select * from tb_BusicInfo where ID= " + ID.ToString() + " ";
SqlCommand command = new SqlCommand(commandString, connection);
connection.Open();
SqlDataReader reader = command.ExecuteReader();
if (reader.Read())
{
tbxUserName.Text = Convert.ToString(reader["Name"]);
cbxGroup.Text = Convert.ToString(reader["Groups"]);
tbxTel.Text = Convert.ToString(reader["Phone"]);
tbxWorkUnit.Text = Convert.ToString(reader["WorkUnit"]);
tbxEmail.Text = Convert.ToString(reader["Email"]);
tbxQQ.Text = Convert.ToString(reader["QQ"]);
if (reader["Picture"] == DBNull.Value)
{
pbxPicture.Image = TongXunLu.Properties.Resources.defaultPix;
}
else
{
// string a=reader["Picture"].ToString();
// byte[] b = (byte[])((reader["Picture"]));
MemoryStream buf = new MemoryStream((byte[])reader["Picture"]);
Image image = Image.FromStream(buf);
Bitmap bt = new Bitmap(image);
pbxPicture.Image = bt;
//pbxPicture.Image = image;
// pbxPicture.Image = Image.FromStream(new MemoryStream(b));//把二进制流读出来??问题
}
}
reader.Close();
connection.Close();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
读数据的时候，但是在写数据的时候可能发生了一些错误。
果然我在追寻byte[]的数组的时候发现 写的时候有2万多个 读的时候只有50个
于是我想可能是写的时候出了问题，于是
commandInsert.Parameters.Add("@Picture", SqlDbType.Image,50);
改为commandInsert.Parameters.Add("@Picture", SqlDbType.Image);
照片可以正常显示了
参考了http://blog.csdn.net/zystory/article/details/4399338
你存数据的时候出了问题，和读数据没有关系
new SqlParameter("@L_RolePic", SqlDbType.Image, 16) 改为 new SqlParameter("@L_RolePic", SqlDbType.Image),
sql读写图片时Image.FromStream方法提示参数错误问题解决
时间： 2024-08-13 00:05:36