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C# 如何连接Datagridview行值并将其存储到一个datatable单元格中_C#_Datagridview_Nullreferenceexception_Concat - Fatal编程技术网

C# 如何连接Datagridview行值并将其存储到一个datatable单元格中

C# 如何连接Datagridview行值并将其存储到一个datatable单元格中,c#,datagridview,nullreferenceexception,concat,C#,Datagridview,Nullreferenceexception,Concat,我有一个带有一列的datagridview,我想连接datagridview行和值 将它们插入一个数据表单元格中。这是我试过的代码 private string concatArticle() { string libArt = null; foreach(DataGridViewRow row1 in ListeArt.Rows) { if (row1 != null) {

我有一个带有一列的datagridview,我想连接datagridview行和值

将它们插入一个数据表单元格中。这是我试过的代码

private string  concatArticle()
    {
        string libArt = null;

        foreach(DataGridViewRow row1 in ListeArt.Rows)
        {
            if (row1 != null)
            {
                libArt = string.Join(",", row1.Cells.Cast<DataGridViewCell>().Select(c => c.Value.ToString()).ToArray());
            }
        }
        return libArt;
    }
但是当我执行这个代码时,我得到了这个错误消息


NullReferenceException:对象引用未设置为对象的实例

错误在哪里

提前谢谢。

试试这个-

private string  concatArticle()
{
    string libArt = string.Join(", ", ListeArt.Rows.OfType<DataGridViewRow>()
                   .Select(i => i.Cells["yourColumnName"].Value.ToString()).ToArray());
    return libArt;
}
private string concatArticle()
{
string libArt=string.Join(“,”,listart.Rows.OfType()的
.Select(i=>i.Cells[“yourColumnName”].Value.ToString()).ToArray());
归还利巴特;
}

单元格中的值为
null

首先执行空检查:

string.Join(",", row1.Cells.Cast<DataGridViewCell>().Where( c => c.Value != null ).Select( c => c.Value.ToString()).ToArray());
string.Join(“,”,row1.Cells.Cast()。其中(c=>c.Value!=null)。选择(c=>c.Value.ToString()).ToArray();
试试这个:

libArt +=  string.Join(",", row1.Cells.Cast<DataGridViewCell>().Where(c => c.Value != null).Select(c => c.Value.ToString()).ToArray());
libArt+=string.Join(“,”,row1.Cells.Cast()。其中(c=>c.Value!=null)。选择(c=>c.Value.ToString()).ToArray();

您的文本框有值吗?在哪一行上出现错误是的,行中有值错误在这里:libArt=string.Join(“,”,row1.Cells.Cast()。选择(c=>c.Value.ToString()).ToArray();NullReferenceException:对象引用未设置为对象的实例。请检查生成的字符串,该字符串显然对您的参数无效。您必须对此进行调试当我尝试您的代码时,错误消失了,但没有在boncommand表中插入任何内容(插入的所有值都是LibArticle除外),错误在哪里?我猜网格中LibArticle的单元格值为null,因此参数也为null。调试它调试为什么sqlparameter为空抱歉我不明白你能解释更多吗
libArt +=  string.Join(",", row1.Cells.Cast<DataGridViewCell>().Where(c => c.Value != null).Select(c => c.Value.ToString()).ToArray());