我知道如何将信息从Form1发送到Form2,但如果数据包含在List<;T>;表格1
本文关键字:List 数据包 lt gt 如果 表格 信息 Form1 Form2 我知道 | 更新日期: 2023-09-27 18:24:11
我有这个代码可以将它从Form1发送到Form2:
public partial class Form1 : Form
{
public ShoppingBasket myBasket = new ShoppingBasket();
public Form1()
{
InitializeComponent();
}
private void editButton_Click(object sender, EventArgs e)
{
int c = lstCart.Items.Count - 1;
for (int i = c; i <= 0; i++)
{
if (lstCart.GetSelected(i))
{
Form2 fm2 = new Form2();
fm2.productNameTextBox.Text = myBasket[i].ProductName;
fm2.quantityTextBox.Text = Convert.ToString(myBasket[i].Quantity);
fm2.latestPriceTextBox.Text = Convert.ToString(myBasket[i].LatestPrice);
fm2.ShowDialog();
}
}
}
}
这是我的Form2代码:
public partial class Form2 : Form
{
public Form2()
{
InitializeComponent();
}
Form1 fm1 = new Form1();
private void okBtn_Click(object sender, EventArgs e)
{
int c = fm1.lstCart.Items.Count - 1;
for (int i = c; i <= 0; i++)
{
if (this.fm1.lstCart.GetSelected(i))
{
this.fm1.myBasket[i].ProductName = this.productNameTextBox.Text;
this.fm1.myBasket[i].Quantity = Convert.ToInt32(this.quantityTextBox.Text);
this.fm1.myBasket[i].LatestPrice = Convert.ToDecimal(this.latestPriceTextBox.Text);
this.Close();
}
}
}
private void cancelBtn_Click(object sender, EventArgs e)
{
this.Close();
}
}
这是我的购物篮类:
public class ShoppingBasket : List<OrderItem>
{
public ShoppingBasket()
{
}
public decimal BasketTotal { get; set; }
public new void Add(OrderItem i)
{
base.Add(i);
}
public new void Remove(OrderItem i)
{
base.Remove(i);
}
订单项类别:
public class OrderItem
{
public OrderItem(string productName,
decimal latestPrice, int quantity)
{
ProductName = productName;
LatestPrice = latestPrice;
Quantity = quantity;
TotalOrder = latestPrice * quantity;
}
public string ProductName { get; set; }
public decimal LatestPrice { get; set; }
public int Quantity { get; set; }
public decimal TotalOrder { get; set; }
}
我遇到的问题是,它给了我:"ArgumentOutOfRangeException未处理",说"Index-1超出范围。参数名称:Index"指向此行:如果(this.fm1.lstCart.GetSelected(i))
但之前它给了我另一个错误,说"对象引用没有设置为对象的实例。"
如何将Form1中先前选定字段中的值更改为从Form2传递回Form1的值?
正如daniel所提到的,你需要将对form1的引用传递到form2,我个人会在构造函数中完成
public Form2(Form1 form)
{
fm1 = form;
}
然后你真的应该尽可能只更新表单中的表单字段,因为form2是模态的,我会做一些类似于这个的事情
using(Form2 fm2 = new Form2(this))
{
fm2.productNameTextBox.Text = myBasket[i].ProductName;
fm2.quantityTextBox.Text = Convert.ToString(myBasket[i].Quantity);
fm2.latestPriceTextBox.Text = Convert.ToString(myBasket[i].LatestPrice);
if(DialogResult.OK == fm2.ShowDialog(this))
{
myBasket[i].ProductName = frm2.productNameTextBox.Text;
myBasket[i].Quantity = Convert.ToInt32(frm2.quantityTextBox.Text);
myBasket[i].LatestPrice = Convert.ToDecimal(frm2.latestPriceTextBox.Text);
}
}
然后使用关闭窗体2
this.DialogResult = DialogResult.OK;
当您在Form2
中创建new Form1()
时,您正在创建一个没有填充数据的全新Form1。不是最初的Form1调用Form2。
所以,你需要的是将Form1
设置为原来的,而不是新的:
public partial class Form2 : Form
{
public Form2()
{
InitializeComponent();
}
public Form1 fm1; //just declare, but let Form1 do the assign job.
//the rest of the code...
}
在表格1 中
for (int i = c; i <= 0; i++)
{
if (lstCart.GetSelected(i))
{
Form2 fm2 = new Form2();
fm2.productNameTextBox.Text = myBasket[i].ProductName;
fm2.quantityTextBox.Text = Convert.ToString(myBasket[i].Quantity);
fm2.latestPriceTextBox.Text = Convert.ToString(myBasket[i].LatestPrice);
//here is the news:
fm2.fm1 = this;
fm2.ShowDialog();
}
}