从其他c#方法访问动态创建的控件
本文关键字：创建 控件 动态 访问 其他 方法 | 更新日期: 2023-09-27 18:07:14
我试图通过点击按钮访问我动态创建的Textbox。
private void assortiment_Load(object sender, EventArgs e)
{
string lastorder = "Select MAX(idorders) From orders";
string query = "Select * From Product";
var cmd = new MySqlCommand(lastorder, connection);
cmd.CommandType = CommandType.Text;
int orderid = Convert.ToInt32(cmd.ExecuteScalar());
label1lblorderid.Text = orderid.ToString();
var cmd2 = new MySqlCommand(query, connection);
var da = new MySqlDataAdapter(cmd2);
var ds = new DataSet();
da.Fill(ds, "Image");
int count = ds.Tables["Image"].Rows.Count;
var y = 3;
for (int i = 0; i < count; i++)
{
var data = (Byte[])(ds.Tables["Image"].Rows[i]["Image"]);
var stream = new MemoryStream(data);
//picture box creation
var pbList = new PictureBox
{
Name = "pic" + i,
Size = new Size(150, 150),
SizeMode = PictureBoxSizeMode.StretchImage,
Image = Image.FromStream(stream)
};
//panel creation
var tblPanelList = new TableLayoutPanel
{
Name = "tblp" + i,
Size = new Size(380, 150),
Location = new System.Drawing.Point(219, y),
BackColor = Color.ForestGreen,
GrowStyle = TableLayoutPanelGrowStyle.AddColumns,
ColumnCount = 2
};
//other
productid = Convert.ToInt32((ds.Tables["Image"]
.Rows[i]["idproduct"]).ToString());
//Textbox: Aantal
var tbAantal = new TextBox { Size = new Size(107, 20),
Name = "tbaantal" + productid};
//label productid
var lblproductid = new Label();
lblproductid.Text = productid.ToString();
//Button: Bestellen
var btnBestel = new Button();
btnBestel.Name = "bestel" + productid;
btnBestel.Text = "Bestellen";
btnBestel.Anchor = AnchorStyles.Right;
btnBestel.Click += btnBestel_Click;
//Voeg controls toe
this.panel.Controls.Add(pbList);
this.Controls.Add(tblPanelList);
tblPanelList.Controls.Add(naam);
tblPanelList.Controls.Add(omschrijving);
tblPanelList.Controls.Add(lblAantal);
tblPanelList.Controls.Add(tbAantal);
tblPanelList.Controls.Add(btnBestel,1,10);
tblPanelList.Controls.Add(lblproductid);
y = y + 156;
}
}
void btnBestel_Click(object sender, EventArgs e)
{
MainForm frm_1 = new MainForm();
var button = sender as Button;
string btnname = button.Name.ToString();
//btnname.Remove(1, 6);
int orderid = Convert.ToInt32(label1lblorderid.Text);
Control tbAantalControl = FindControl("tbAantal" + btnname.Remove(0, 6));
int aantal = Convert.ToInt32(tbAantalControl.Text);
//MessageBox.Show(btnname.Remove(0,6));
string query = "Insert Into orderproduct(idorder, idproduct, aantal)
Values('" + orderid + "'" + productid +
"'" + aantal + "')";
var cmd = new MySqlCommand(query, connection);
cmd.ExecuteNonQuery();
}
正如您所看到的，我已经尝试通过FindControl()访问Textbox，但这不起作用。我想要的Textbox具有相同的最后值点击TextBox，我试图做到这一点，通过剪切字符串和粘贴在一个变量。
请帮。
首先，您正在搜索与您创建它们的名称不同的TextBox es (tbAantal... vs. tbaantal...)。与递归Find方法一起，将工作。
这既不是好的做法，也不是快。
与其每次创建控件时都按名称搜索控件，不如直接实现让您检索控件(通过一些标识符或类似的，在您的情况下:通过productid)。
将Dictionary<int, TextBox> textBoxes声明为局部变量。在循环中，在tbAantal的定义之后添加textBoxes.Add(productid, tbAantal);。
在btnBestel_Click中，您可以使用此映射通过textBoxes[productid]检索正确的TextBox。我知道你并没有真正在那个上下文中定义productid。
您应该使用Buttons的Tag属性，而不是使用btnname.Remove(0, 6)，并将productid作为额外的元数据存储:
回到循环中，在适当的位置添加btnBestel.Tag = productid;。在btnBestel_Click中，你可以写textBoxes[(int)button.Tag] .
总的代码
Dictionary<int, TextBox> textBoxes = new Dictionary<int,TextBox>();
private void assortiment_Load(object sender, EventArgs e)
{
string lastorder = "Select MAX(idorders) From orders";
string query = "Select * From Product";
var cmd = new MySqlCommand(lastorder, connection);
cmd.CommandType = CommandType.Text;
int orderid = Convert.ToInt32(cmd.ExecuteScalar());
label1lblorderid.Text = orderid.ToString();
var cmd2 = new MySqlCommand(query, connection);
var da = new MySqlDataAdapter(cmd2);
var ds = new DataSet();
da.Fill(ds, "Image");
int count = ds.Tables["Image"].Rows.Count;
var y = 3;
for (int i = 0; i < count; i++)
{
var data = (Byte[])(ds.Tables["Image"].Rows[i]["Image"]);
var stream = new MemoryStream(data);
//picture box creation
var pbList = new PictureBox
{
Name = "pic" + i,
Size = new Size(150, 150),
SizeMode = PictureBoxSizeMode.StretchImage,
Image = Image.FromStream(stream)
};
//panel creation
var tblPanelList = new TableLayoutPanel
{
Name = "tblp" + i,
Size = new Size(380, 150),
Location = new System.Drawing.Point(219, y),
BackColor = Color.ForestGreen,
GrowStyle = TableLayoutPanelGrowStyle.AddColumns,
ColumnCount = 2
};
//other
productid = Convert.ToInt32((ds.Tables["Image"]
.Rows[i]["idproduct"]).ToString());
//Textbox: Aantal
var tbAantal = new TextBox { Size = new Size(107, 20),
Name = "tbaantal" + productid};
textBoxes.Add(productid, tbAantal);
//label productid
var lblproductid = new Label();
lblproductid.Text = productid.ToString();
//Button: Bestellen
var btnBestel = new Button();
btnBestel.Name = "bestel" + productid;
btnBestel.Text = "Bestellen";
btnBestel.Anchor = AnchorStyles.Right;
btnBestel.Click += btnBestel_Click;
btnBestel.Tag = productid;
//Voeg controls toe
this.panel.Controls.Add(pbList);
this.Controls.Add(tblPanelList);
tblPanelList.Controls.Add(naam);
tblPanelList.Controls.Add(omschrijving);
tblPanelList.Controls.Add(lblAantal);
tblPanelList.Controls.Add(tbAantal);
tblPanelList.Controls.Add(btnBestel,1,10);
tblPanelList.Controls.Add(lblproductid);
y = y + 156;
}
}
void btnBestel_Click(object sender, EventArgs e)
{
MainForm frm_1 = new MainForm();
var button = sender as Button;
int orderid = Convert.ToInt32(label1lblorderid.Text);
Control tbAantalControl = textBoxes[(int)button.Tag];
int aantal = Convert.ToInt32(tbAantalControl.Text);
string query = "Insert Into orderproduct(idorder, idproduct, aantal)
Values('" + orderid + "'" + productid +
"'" + aantal + "')";
var cmd = new MySqlCommand(query, connection);
cmd.ExecuteNonQuery();
}
我不确定您是否为搜索提供了有效的控件名称。对于检查，您应该在行上应用断点，以查看您是否获得有效的控件名称。
要按名称搜索所需的控件，应该递归地查看每个父控件。FindControl方法可用于此目的。
改变:
Control tbAantalControl = FindControl("tbAantal" + btnname.Remove(0, 6));
Control tbAantalControl = FindControl(this.Controls, "tbAantal" + btnname.Remove(0, 6));
递归找到所需的方法:
private Control FindControl(Control.ControlCollection controlCollection, string name)
{
foreach (Control control in controlCollection)
{
if (control.Name.ToLower() == name.ToLower())
{
return control;
}
if (control.Controls.Count > 0)
{
Control result = FindControl(control.Controls, name);
if (result != null)
{
return result;
}
}
}
return null;
}
是否有任何原因，你不能只是使tbAantal的形式级别变量，然后在btnBestel_Click方法中引用?
var tbAantal = null;
private void assortiment_Load(object sender, EventArgs e)
{
string lastorder = "Select MAX(idorders) From orders";
string query = "Select * From Product";
var cmd = new MySqlCommand(lastorder, connection);
cmd.CommandType = CommandType.Text;
int orderid = Convert.ToInt32(cmd.ExecuteScalar());
label1lblorderid.Text = orderid.ToString();
var cmd2 = new MySqlCommand(query, connection);
var da = new MySqlDataAdapter(cmd2);
var ds = new DataSet();
da.Fill(ds, "Image");
int count = ds.Tables["Image"].Rows.Count;
var y = 3;
for (int i = 0; i < count; i++)
{
var data = (Byte[])(ds.Tables["Image"].Rows[i]["Image"]);
var stream = new MemoryStream(data);
//picture box creation
var pbList = new PictureBox
{
Name = "pic" + i,
Size = new Size(150, 150),
SizeMode = PictureBoxSizeMode.StretchImage,
Image = Image.FromStream(stream)
};
//panel creation
var tblPanelList = new TableLayoutPanel
{
Name = "tblp" + i,
Size = new Size(380, 150),
Location = new System.Drawing.Point(219, y),
BackColor = Color.ForestGreen,
GrowStyle = TableLayoutPanelGrowStyle.AddColumns,
ColumnCount = 2
};
//other
productid = Convert.ToInt32((ds.Tables["Image"].Rows[i]["idproduct"]).ToString());
//Textbox: Aantal
tbAantal = new TextBox { Size = new Size(107, 20), Name = "tbaantal" + productid};
//label productid
var lblproductid = new Label();
lblproductid.Text = productid.ToString();
//Button: Bestellen
var btnBestel = new Button();
btnBestel.Name = "bestel" + productid;
btnBestel.Text = "Bestellen";
btnBestel.Anchor = AnchorStyles.Right;
btnBestel.Click += btnBestel_Click;
//Voeg controls toe
this.panel.Controls.Add(pbList);
this.Controls.Add(tblPanelList);
tblPanelList.Controls.Add(naam);
tblPanelList.Controls.Add(omschrijving);
tblPanelList.Controls.Add(lblAantal);
tblPanelList.Controls.Add(tbAantal);
tblPanelList.Controls.Add(btnBestel,1,10);
tblPanelList.Controls.Add(lblproductid);
y = y + 156;
}
}
void btnBestel_Click(object sender, EventArgs e)
{
MainForm frm_1 = new MainForm();
var button = sender as Button;
string btnname = button.Name.ToString();
//btnname.Remove(1, 6);
int orderid = Convert.ToInt32(label1lblorderid.Text);
int aantal = Convert.ToInt32(tbAantal.Text);
//MessageBox.Show(btnname.Remove(0,6));
string query = "Insert Into orderproduct(idorder, idproduct, aantal) Values('" + orderid + "'" + productid +
"'" + aantal + "')";
var cmd = new MySqlCommand(query, connection);
cmd.ExecuteNonQuery();
}