问题描述
大家好，我有winform c＃2012
我已经定义了一个datagridview，其中有一个值。我的datagridview有2列（绿色和红色），如下所示：
------------------------
GREEN | RED | // daatagridview的标题
-----------------------
A | B |
-----------------------
C | A |
-----------------------
D | D |
-----------------------
E | Z |
-----------------------
E | Z |
-----------------------
我想做的是安排datagridview使得
- 两列中出现的所有项目都从GREEN列中删除
- 在同一列中出现多次的每个项目，只保留一个，其余的重复项被删除（即：同一列中的重复数据被删除）
所以上面的datagridview应该在转换后变成这样：
------------------------
GREEN | RED | // daatagridview的标题
-----------------------
E | B |
-----------------------
C | A |
-----------------------
E | D |
-----------------------
| Z |
------------------------
我试过的确有效吗
我该怎么办？
提前谢谢
我尝试过：
hi all, i have winform c# 2012
i have defined a datagridview in which there is a values. My datagridview has 2 columns (GREEN and RED ) and looks as follow:
------------------------
GREEN | RED | //headers of daatagridview
-----------------------
A | B |
-----------------------
C | A |
-----------------------
D | D |
-----------------------
E | Z |
-----------------------
E | Z |
-----------------------
what i want to do is to arrange the datagridview such that
-every item that appears in both columns is removed from GREEN column
-every item that appears more than one time in a same column, only one is kept ,the rest of duplicates is removed (ie: duplicate data in the same column are removed)
so the above datagridview should become after transformation like this:
------------------------
GREEN | RED | //headers of daatagridview
-----------------------
E | B |
-----------------------
C | A |
-----------------------
E | D |
-----------------------
| Z |
------------------------
what i have tried does work
how can i do it?
thanks in advance
What I have tried:
List<string> list = new List<string>();
for (int i = 0; i < dataGridView1.Rows.Count; i++)
{
if (dataGridView1.Rows[i].Cells[0].Value != null)
{
string str_green = dataGridView1.Rows[i].Cells[0].Value.ToString();
if (!list.Contains(str_green))
{
list.Add(str_green);
}
else
{
dataGridView1.Rows.Remove(dataGridView1.Rows[i]);
}
}
if (dataGridView1.Rows[i].Cells[1].Value != null)
{
string str_red = dataGridView1.Rows[i].Cells[1].Value.ToString();
if (!list.Contains(str_red))
{
list.Add(str_red);
}
else
{
dataGridView1.Rows.Remove(dataGridView1.Rows[i]);
}
}
//}推荐答案
//get the "red" items first (because if they appear in both we don't want them in the green list)
var redItems = (dt.AsEnumerable().Where(x => x.Field<string>("Flag_created") == "Red")
.Select(x => x.Field<string>("Society_Id"))).Distinct().ToList();
int r = redItems.Count();
//Get the "green" items
var greenItems = (dt.AsEnumerable()
.Where(x => x.Field<string>("Flag_created") == "Green")
.Select(x => x.Field<string>("Society_Id"))).Except(redItems).Distinct().ToList();
int g = greenItems.Count();
// Whichever is the greater count of items, add that many rows to the grid
dataGridView1.Rows.Add(Math.Max(g, r));
for (var i = 0; i < dataGridView1.Rows.Count; i++)
{
if (i < greenItems.Count)
dataGridView1.Rows[i].Cells[greenColumn].Value = greenItems[i];
if (i < redItems.Count)
dataGridView1.Rows[i].Cells[redColumn].Value = redItems[i];
}
注意事项：
- redItems和greenItems现在 List< string> 不是列表< datagridviewrow>
- 我首先得到redItems因为我想从greenItems中排除任何一个 - 请参阅 []
- 我只想要唯一的值，所以请注意 []
- 还要注意我从以前的解决方案填充dataGridView的方式不同（因为列表项现在是字符串）
为了完整性，如果已经填充了DataGridView，则可以将列转换为Lists t o稍后进行此操作...我创建了一个按钮来删除这样的重复项
Things to note:
- redItems and greenItems are now List<string> not List<datagridviewrow>
- I get the redItems first because I want to exclude any of those from the greenItems - see the .Except[^]
- I only want unique values so note the .Distinct[^]
- Also note the difference to how I'm populating the dataGridView from my previous solution (because the list items are now strings)
For completeness, if you already have a DataGridView populated you can convert the columns into Lists to do this manipulation later ... I created a button to remove the duplicates like this
private void removeDups_Click(object sender, EventArgs e)
{
var redList = dataGridView1.Rows
.OfType<DataGridViewRow>()
.Where(x => x.Cells[redColumn].Value != null)
.Select(x => x.Cells[redColumn].Value.ToString())
.Distinct()
.ToList();
var greenList = (from DataGridViewRow dr in dataGridView1.Rows
where dr.Cells[greenColumn].Value != null
select dr.Cells[greenColumn].Value.ToString()).Distinct().Except(redList).ToList();
dataGridView1.Rows.Clear();
dataGridView1.Rows.Add(Math.Max(greenList.Count(), redList.Count()));
for (var i = 0; i < dataGridView1.Rows.Count; i++)
{
if (i < greenList.Count)
dataGridView1.Rows[i].Cells[greenColumn].Value = greenList[i];
if (i < redList.Count)
dataGridView1.Rows[i].Cells[redColumn].Value = redList[i];
}
}
注意事项：
- 我使用了两种不同的方法来转换列表中的红色和绿色列 - 使用您感觉更舒适的方法。他们仍然使用 .Distinct（）和 .Except（）
正如我在此解决方案的顶部所说的那样 - 当您填充dataGridView（即数据表）的数据源时，最好注意这些事情。我建议替代方案，但我不知道你是如何得到你的数据的。
Things to note:
- I used two different methods to convert the red and green columns to lists - use whichever method you feel more comfortable with. They still both use .Distinct() and .Except()
As I said right at the top of this solution though - these things are best taken care of when you are populating the datasource for the dataGridView (i.e. the datatable). I'd suggest alternatives but I don't know how you are getting your data.
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