向单元格赋值时，DataGridView SLOW

本文介绍了向单元格赋值时，DataGridView SLOW的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 我似乎无法弄清楚这里发生了什么...我有一个dataGridView，在任何给定时间不超过500行，但通常大约200或300.我遍历网格并设置按钮文本和颜色根据用户互动。例如： I can't seem to figure out what's going here...I have a dataGridView with no more than 500 rows at any given time but usually around 200 or 300. I iterate through the grid and set the button text and color according user interaction. Example:using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;namespace WindowsFormsApplication1{ public partial class Form1 : Form { DataGridViewButtonColumn btn; ContextMenuStrip ctxtStartStop; public Form1() { InitializeComponent(); formatGrid(); populateGrid(); ctxtStartStop = new ContextMenuStrip(); ctxtStartStop.Items.Add("START ALL"); ctxtStartStop.Items.Add("STOP ALL"); ctxtStartStop.ItemClicked += new ToolStripItemClickedEventHandler(ctxtMenuStrip_ItemClicked); } private void formatGrid() { btn = new DataGridViewButtonColumn(); btn.Text = "START"; btn.Name = "colStartStop"; btn.HeaderText = "Start/Stop"; btn.DefaultCellStyle.BackColor = Color.LightGreen; btn.DefaultCellStyle.ForeColor = Color.Black; btn.ReadOnly = false; btn.UseColumnTextForButtonValue = false; btn.FlatStyle = FlatStyle.Standard; btn.AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; gridDisplay.AutoGenerateColumns = false; gridDisplay.AllowUserToAddRows = false; gridDisplay.RowHeadersVisible = false; gridDisplay.Columns.Add(new DataGridViewTextBoxColumn() { Name = "colSymbol", HeaderText = "Symbols", ReadOnly = true, AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill, MinimumWidth = 50 }); gridDisplay.Columns.Add(btn); gridDisplay.MouseClick += new MouseEventHandler(gridDisplay_MouseClick); } private void populateGrid() { for (int i = 0; i < 500; i++) { gridDisplay.Rows.Add("XYZ", "START"); } } private void gridDisplay_MouseClick(object sender, MouseEventArgs e) { if (e.Button == System.Windows.Forms.MouseButtons.Left) return; int rowPosition = gridDisplay.HitTest(e.X, e.Y).RowIndex; int colPosition = gridDisplay.HitTest(e.X, e.Y).ColumnIndex; if (rowPosition == -1 && colPosition == 1) { ctxtStartStop.Show(gridDisplay.PointToScreen(e.Location)); } } private void ctxtMenuStrip_ItemClicked(object sender, ToolStripItemClickedEventArgs e) { if (e.ClickedItem.Text == "START ALL") { ctxtStartStop.Hide(); startAll(); } else if (e.ClickedItem.Text == "STOP ALL") { ctxtStartStop.Hide(); stopAll(); } } private void startAll() { string action = string.Empty; int idx = 1; for (int i = 0; i < gridDisplay.Rows.Count; i++) { var btnCell = gridDisplay.Rows[i].Cells[idx]; action = (string)btnCell.Value; if (action == "START") { btnCell.Value = "STOP"; gridDisplay.Rows[i].Cells["colStartStop"].Style.BackColor = Color.Red; gridDisplay.Rows[i].Cells["colStartStop"].Style.ForeColor = Color.White; } } } private void stopAll() { string action = string.Empty; int idx = 1; for (int i = 0; i < gridDisplay.Rows.Count; i++) { var btnCell = gridDisplay.Rows[i].Cells[idx]; action = (string)btnCell.Value; if (action == "STOP") { btnCell.Value = "START"; gridDisplay.Rows[i].Cells["colStartStop"].Style.BackColor = Color.LightGreen; gridDisplay.Rows[i].Cells["colStartStop"].Style.ForeColor = Color.Black; } } } }} 好​​笑事情是设置颜色工作正常，但当我设置它运行非常慢。 有人可以解释我在这里做错了什么。 谢谢， -DA The funny thing is that setting the Colors works fine but when I set the Value it runs extremely slow.Can someone please explain what I'm doing wrong here.Thank you,-DA推荐答案 void ProcessData(string info) { int helloWorldColumnIndex = 0; int backColorColumnIndex = 0; int foreColorColumnIndex = 0; for (int i = 0; i < dataGrid.Rows.Count; ++i) { if (i == 0) { // using those "colHelloWorld" is also bad, but this is all I know from this code sample // in real code, use only helloWorldColumnIndex, backColorColumnIndex, foreColorColumnIndex, // have them known in advance... helloWorldColumnIndex = dataGrid.Rows[i].Cells["colHelloWorld"].ColumnIndex; backColorColumnIndex = dataGrid.Rows[i].Cells["colBackColor"].ColumnIndex; foreColorColumnIndex = dataGrid.Rows[i].Cells["colForeColor"].ColumnIndex; } //if first time var gridInfoCell = dataGrid.Rows[i].Cells[helloWorldColumnIndex]; string gridInfo = (string)gridInfoCell.Value; if (gridInfo == info) { gridInfoCell.Value = "Good by, and don't hard-code immediate constants anymore!"; dataGrid.Rows[i].Cells[backColorColumnIndex].Style.BackColor = Color.Red; dataGrid.Rows[i].Cells[ForeColorColumnIndex].Style.ForeColor = Color.White; } //if right info } //loop} //ProcessData 当然，这不是最好的选择，因为你可以确定列索引首先，当您设置整个网格视图时。我只展示了孤立的解决方案，仅基于您现有的代码，而不是其他任何内容。当然，您不应该使用那些立即字符串常量。我希望你有这个主意。 很棒， ++ i 而不是 i ++ 提供更好的性能。 （但是将此变量重命名为 index 或者其他内容。切勿使用单字符标识符。） b $ b 代码示例根据OP问题文本中代码示例的最后修改进行修改。 然而，这些改进只是非常无意义的争吵。整个方法都是错误的。从根本上说，网格视图性能的唯一真正关键是虚拟模式。请参阅： http：// msdn .microsoft.com / zh-cn / library / system.windows.forms.datagridview.virtualmode.aspx [ ^ ]。 -SA Of course, this is not the best option, because you could determine the column indices in first place, when you set up the whole grid view. I only demonstrated the isolated solution, based only on your existing code and nothing else. Of course, you should not use those immediate string constants. I hope you got the idea.Wonderfully, ++i instead of i++ gives better performance. (But rename this variable to "index" or something. Never use single-character identifiers.)The code sample is modified according to last modification of the code sample in the text of the question by OP.However, these improvements are just pretty much pointless rat race. The whole approach is wrong. Radically, the only real key to grid view performance is its virtual mode. Please see:http://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.virtualmode.aspx[^].—SA 这篇关于向单元格赋值时，DataGridView SLOW的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！