我正在尝试将mysql数据库中的图像作为blob图像保存到windows应用程序的图片框中。
这是我的密码。
private Image GetFaceFromDB()
{
Image fetchedImage;
if (rowNumber >= 0)
{
byte[] faceTobyte = (byte[])dataTable.Rows[rowNumber]
["Image"];
MemoryStream stream = new MemoryStream(faceTobyte);
fetchedImage = Image.FromStream(stream);**//Error at this
line**
return fetchedImage;
}else
{
MessageBox.Show("There are no images in thedatabase,please
insert images.");
return null;
}
}
这是按钮点击事件
private void btnFirst_Click(object sender, EventArgs e)
{
RefreshDBConnection();
rowNumber = 0;
pbTrainingSetImages.Image = GetFaceFromDB();
tbUpdateFaceName.Text = dataTable.Rows[rowNumber]["Name"].ToString();
lbFaceNumber.Text = (rowNumber + 1).ToString();
if(pbTrainingSetImages.Image != null)
{
MessageBox.Show("You have reached the First image in the
database!");
}
}
我还尝试了以下代码
一
private void btnFirst_Click(object sender, EventArgs e)
{
RefreshDBConnection();
rowNumber = 0;
pbTrainingSetImages.Image = GetFaceFromDB();
tbUpdateFaceName.Text = dataTable.Rows[rowNumber]
["Name"].ToString();
lbFaceNumber.Text = (rowNumber + 1).ToString();
if(pbTrainingSetImages.Image != null)
{
MessageBox.Show("You have reached the First image in the
database!");
}
}
b
private Image GetFaceFromDB()
{
Image fetchedImage;
if (rowNumber >= 0)
{
byte[] faceTobyte= (byte[])dataTable.Rows[rowNumber["Image"];
MemoryStream stream = new MemoryStream();
stream.Position = 0;
return fetchedImage = Image.FromStream(stream, false);
}
else
{
MessageBox.Show("There are no images in the database, please
insert
images.");
return null;
}
}
c
private Image GetFaceFromDB()
{
Image fetchedImage;
if (rowNumber >= 0)
{
byte[] faceTobyte = (byte[])dataTable.Rows[rowNumber]["Image"];
MemoryStream stream = new MemoryStream();
stream.Position = 0;
return fetchedImage = Image.FromStream(stream, false);
}
else
{
MessageBox.Show("There are no images in the database,please insert
images.");
return null;
}
}
d
private Image GetFaceFromDB()
{
Image fetchedImage;
if (rowNumber >= 0)
{
byte[] faceTobyte = (byte[])dataTable.Rows[rowNumber]
["Image"];
using(var stream = new MemoryStream(faceTobyte))
{
fetchedImage = Image.FromStream(stream);
return fetchedImage;
}
}
else
{
MessageBox.Show("There are no images in the database, please
insert images.");
return null;
}
}
我还尝试了这些堆栈溢出链接中提供的大多数答案:
使用内存流将二进制文件转换为位图
image.memorystream:参数无效
参数无效
字节数组到图像的转换
这是错误消息参数在此行无效
fetchedImage = Image.FromStream(stream);
这是我的插入语句
private void AddFacesToDB(Image inputImage, string inputLabel)
{
if (connection.State.Equals(ConnectionState.Closed))
{
connection.Open();
}
try
{
//convert the face image to byte format for storing in db
byte[] facesToByte = ConvertFaceToDBFormat(inputImage);
totalRows++;
//At what location is the image being stored to
MessageBox.Show($"Adding row {totalRows.ToString()}");
//inserting the image into the row
MySqlCommand insertCommand = new MySqlCommand("insert into
testimages.image_information(FaceID, FaceNo, Name, Image) values('" +
totalRows.ToString() + "','" + totalRows.ToString() + "', '" +
tbSetFaceLabel.Text + "', @IMG)", connection);
MySqlParameter imageParam =
insertCommand.Parameters.AddWithValue("@IMG","Image");
imageParam.Value = facesToByte;
imageParam.Size = facesToByte.Length;
int rowAffected = insertCommand.ExecuteNonQuery();
MessageBox.Show("Data Stored Successfully in " +
rowAffected.ToString() + " Rows");
}catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
RefreshDBConnection();
}
}
这是我的数据库
1条答案
按热度按时间o4tp2gmn1#
我终于解决了。在花了6个小时之后。坚持是有好处的。我的陈述是问题出在我身上,
我一直在把“图像”解析成字节,不知道我没有解析一个有效的图像格式。所以我把我的插入语句编辑成:
现在,正在传递正确的图像格式,并且图像显示在图片框中。