想在我的数据库和数据网格视图中进行更新 [英] want to make update in my database and datagrid view
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问题描述
美好的一天,
我写了一个代码来更新DataGridView中的单元格,但是在运行异常时发生了
索引超出范围。必须是非负数且小于集合的大小。
参数名称:index
我不知道是什么问题,我的代码有什么问题吗?
注意:我创建了一个DBclass包含所有sqlcommands和i cast当我需要写quires时。
这是我的代码:
private void btn_update_Click( object sender,EventArgs e)
{
DBClass db = DBClass.GetInstance();
for ( int i = 0 ; i< = dgv_contents.RowCount; i ++)
{
string str = @
UPDATE [Picture_upload]。[dbo]。[Contents]
SET [cont_name] =' + dgv_contents.SelectedRows [ i] .Cells [ 0 ]。值+
',[cont_type] =' + dgv_contents.Rows [i] .Cells [ 1 ]。值+
',[Description] =' + dgv_contents.Rows [i] .Cells [ 2 ]。值+
',[price] = + dgv_contents.Rows [i] .Cells [ 3 ]。值+ ;
db.ExecuteNonQuery(str,CommandType.Text);
}
解决方案
DataGridView的RowCount属性为您提供个行。
但每行的索引从0(零)开始。
因此在你的for循环中for ( int i = < = 你在DGV的实际行结束时运行。
将其更改为
试试这个代码..
private void btn_update_Click( object sender,EventArgs e)
{
DBClass db = DBClass.GetInstance ();
foreach (DataGridViewRow row in dgv_contents.SelectedRows )
{
string str = @
UPDATE [Picture_upload]。[dbo]。[Contents]
SET [cont_name] =' + row.Cells [ 0 ]。值+
',[cont_type] =' + row.Cells [ 1 ]。值+
',[Description] =' + row.Cells [ 2 ]。值+
',[price] = + row.Cells [ 3 ] .Value +;
db.ExecuteNonQuery(str,CommandType.Text);
}
}
这对SQL注入攻击是开放的,即使您的表单不允许这些单元格上的文本框。你应该通过存储过程来做到这一点。你不应该在你的表示层写这么多的DB代码。
Good day all,
I wrote a code for updating cells in DataGridView , but while running an Exception occurred
"Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index"
I don't know what's the problem ,Is there anything wrong in my code ?
Note : i made a DBclass contains all sqlcommands and i cast it when i need to write quires.
Here's my Code:
private void btn_update_Click(object sender, EventArgs e)
{
DBClass db=DBClass.GetInstance();
for(int i=0;i<=dgv_contents.RowCount;i++)
{
string str = @"
UPDATE [Picture_upload].[dbo].[Contents]
SET [cont_name] = '"+dgv_contents.SelectedRows[i].Cells[0].Value+
"',[cont_type] ='"+dgv_contents.Rows[i].Cells[1].Value+
"',[Description] ='"+dgv_contents.Rows[i].Cells[2].Value+
"',[price] = "+dgv_contents.Rows[i].Cells[3].Value+"";
db.ExecuteNonQuery(str,CommandType.Text);
}
解决方案
The RowCount property of a DataGridView gives you the number of rows.
But the index of each row starts at 0 (zero).
Thus in your for loopfor(int i=0;i<=dgv_contents.RowCount;i++)
by using<=
you are running off the end of actual rows in the DGV.
Change it to just be
Try this code..
private void btn_update_Click(object sender, EventArgs e) { DBClass db = DBClass.GetInstance(); foreach (DataGridViewRow row in dgv_contents.SelectedRows) { string str = @" UPDATE [Picture_upload].[dbo].[Contents] SET [cont_name] = '" + row.Cells[0].Value + "',[cont_type] ='" + row.Cells[1].Value + "',[Description] ='" + row.Cells[2].Value + "',[price] = " + row.Cells[3].Value + ""; db.ExecuteNonQuery(str, CommandType.Text); } }
This is open to SQL injection attacks, even if your form doesn't allow text boxes on these cells. You should do this via a stored proc. You should NEVER write this much DB code in your presentation layer.
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