有什么解决办法吗"Gridview shows only one data after update new entry."？

Question

每次点击按钮只会显示一行。但它应该显示多行。我在构造函数调用后声明列表。我尝试使用 gridview.update() 和 gridview.refresh() 但它们没有用。我找不到问题。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using JournalEntryApp.Model;

namespace JournalEntryApp
{
    public partial class NewDocument : Form
    {
        public NewDocument()
        {
            InitializeComponent();
        }

        List<JEFrom> JEFromsList = new List<JEFrom>();
        List<JETo> JETosList = new List<JETo>();
        JEFrom _jef = null;

        private void NewDocument_Load(object sender, EventArgs e)
        {
            label4.Text = DateTime.Now.ToString("dd-MMM-yyyy");
            using (var db =new JournalContext())
            {
                unitComboBox.DataSource = db.Units.ToList();
                unitComboBox.ValueMember = "Id";
                unitComboBox.DisplayMember = "UnitName";

            }
        }

        private void addToListButton_Click(object sender, EventArgs e)
        {

            if (string.Empty== fromAccountTextBox.Text)
            {
                MessageBox.Show("From Account can not be empty!!!");
            }
            else if (string.Empty == toAccountTextBox.Text)
            {
                MessageBox.Show("To Account can not be empty!!!");
            }
            else
            {
                _jef = new JEFrom{ FromEntryName= fromAccountTextBox.Text , FromEntryDate= DateTime.Now };
                JEFromsList.Add(_jef);
                temporaryDataGridView.DataSource = JEFromsList;

                fromAccountTextBox.Text = string.Empty;
                toAccountTextBox.Text = string.Empty;



            }

        }
    }
}

Answer 1

temporaryDataGridView 无法检测到您更改了数据源。它只会在数据源发生变化时刷新。

temporaryDataGridView.DataSource = null;
temporaryDataGridView.DataSource = JEFromsList;

所以首先将数据源更改为 null。

或者您可以使用 bindingSource

private void NewDocument_Load(object sender, EventArgs e)
{
    this.bindingSource1.DataSource = JEFromsList;
    temporaryDataGridView.DataSource = this.bindingSource1;

    label4.Text = DateTime.Now.ToString("dd-MMM-yyyy");
    using (var db =new JournalContext())
    {
        unitComboBox.DataSource = db.Units.ToList();
        unitComboBox.ValueMember = "Id";
        unitComboBox.DisplayMember = "UnitName";
    }
}

在button_click

JEFromsList.Add(_jef);
bindingSource1.ResetBindings(true);

有什么解决办法吗"Gridview shows only one data after update new entry."？

Is there any solution "Gridview shows only one data after update new entry."?

c#

gridview