根据查询过滤图像列表和列表视图

Question

它成功地从表中加载项目和图像，但是当我尝试搜索时，没有任何内容出现

这是我在表单加载事件（工作）上的代码

public void IL()
{
imageList1.Images.Clear();
listView1.Items.Clear();
listBox1.Items.Clear();

SqlDataReader dr;
cn.Open();
SqlCommand cmd = new SqlCommand("Select * from EnteryItem ", cn);
dr = cmd.ExecuteReader();
if (dr.HasRows)
{
while (dr.Read())
{
try
{
var imageBytes = (byte[])dr["ItemImage"];
MemoryStream memStm = new MemoryStream(imageBytes);
memStm.Seek(0, SeekOrigin.Begin);
Image image = Image.FromStream(memStm);
imageList1.Images.Add(image);

if (dr["ItemName"].ToString() == "")
{
    listBox1.Items.Add(dr["ItemBarcode"].ToString());
}
else
{
    listBox1.Items.Add(dr["ItemName"].ToString());
}
}
catch
{
Bitmap bmp = new Bitmap(78, 78);
using (Graphics gr = Graphics.FromImage(bmp))
{
    gr.Clear(Color.FromKnownColor(KnownColor.ControlDarkDark));
}
imageList1.Images.Add(bmp);

if (dr["ItemName"].ToString() == "")
{
    listBox1.Items.Add(dr["ItemBarcode"].ToString());
}
else
{
    listBox1.Items.Add(dr["ItemName"].ToString());
}
}
}
dr.Close();


this.imageList1.ImageSize = new Size(100, 100);
imageList1.ColorDepth = ColorDepth.Depth32Bit;
this.listView1.LargeImageList = this.imageList1;
for (int j = 0; j < this.imageList1.Images.Count; j++)
{
ListViewItem item = new ListViewItem();
item.ImageIndex = j;
item.Text = listBox1.Items[j].ToString();
this.listView1.Items.Add(item);
}
}
cn.Close();
}

这是关于文本更改事件的搜索代码（这是问题）

private void search()
{
if (textBox2.Text == "")
{
IL();
}

imageList1.Images.Clear();
listView1.Items.Clear();
listBox1.Items.Clear();

SqlDataReader dr;
cn.Open();
SqlCommand cmd = new SqlCommand("Select * from EnteryItem WHERE ItemName = N'%" + textBox2.Text + "%' Or ItemBarcode = N'" + textBox2.Text + "' ", cn);
dr = cmd.ExecuteReader();
if (dr.HasRows)
{
while (dr.Read())
{
try
{
var imageBytes = (byte[])dr["ItemImage"];
MemoryStream memStm = new MemoryStream(imageBytes);
memStm.Seek(0, SeekOrigin.Begin);
Image image = Image.FromStream(memStm);
imageList1.Images.Add(image);

if (dr["ItemName"].ToString() == "")
{
    listBox1.Items.Add(dr["ItemBarcode"].ToString());
}
else
{
    listBox1.Items.Add(dr["ItemName"].ToString());
}
}
catch
{
Bitmap bmp = new Bitmap(78, 78);
using (Graphics gr = Graphics.FromImage(bmp))
{
    gr.Clear(Color.FromKnownColor(KnownColor.ControlDarkDark));
}
imageList1.Images.Add(bmp);

if (dr["ItemName"].ToString() == "")
{
    listBox1.Items.Add(dr["ItemBarcode"].ToString());
}
else
{
    listBox1.Items.Add(dr["ItemName"].ToString());
}
}
}
dr.Close();


this.imageList1.ImageSize = new Size(100, 100);
imageList1.ColorDepth = ColorDepth.Depth32Bit;
this.listView1.LargeImageList = this.imageList1;
for (int j = 0; j < this.imageList1.Images.Count; j++)
{
ListViewItem item = new ListViewItem();
item.ImageIndex = j;
item.Text = listBox1.Items[j].ToString();
this.listView1.Items.Add(item);
}
}
cn.Close();

}

Answer 1

首先：每次在文本框中输入内容时，都不要设置新图像，而是将它们保存在一个集合中，并将其添加到列表框中，只过滤掉部分内容，例如：listBox1.DataSource = SomeLocalCollection.Where(i=>i.ItemName.Contains(textBox2.Text)).ToList()

另外，使用调试器检查代码中哪个部分出错。

Answer 2

据我所知，%之类的sql和通配符仅适用于LIKE运算符。

SQL Wildcards