Question

希望有人可以帮我解决这个问题。我有一个带有x行数的GridView，每行有4列，包含3个DropDownLists和一个Label，用于保存3个DropDownLists的选定值之和。我的问题是如何实现这一目标？我已经尝试了DropDownLists的SelectedIndexChanged路由，但我没有得到我想要的结果。它们不是被添加，而是被下一个选择覆盖。我究竟做错了什么？这是我到目前为止所做的：


    protected void ddlSelectedIndexChanged(object sender, EventArgs e)
    {
        foreach (GridViewRow row in gvStuRoster.Rows)
        {
            double scores = 0;

            DropDownList ddlFocus = (DropDownList)row.FindControl("ddlFocus");
            DropDownList ddlEvidence = (DropDownList)row.FindControl("ddlEvidence");
            DropDownList ddlConventions = (DropDownList)row.FindControl("ddlConventions");
            //DropDownList ddlScores = (DropDownList)row.FindControl("ddlScores");
            Label lblScores = (Label)row.FindControl("lblScores");

            if (ddlFocus.SelectedIndex > 0 && ddlFocus.SelectedValue != "-1")
            {
                scores += Convert.ToDouble(ddlFocus.SelectedValue);
            }
            else if (ddlFocus.SelectedValue == "-1")
            {
                scores = -1;
            }

            if (ddlEvidence.SelectedIndex > 0 && ddlEvidence.SelectedValue != "-1")
            {
                scores += Convert.ToDouble(ddlEvidence.SelectedValue);
            }
            else if (ddlEvidence.SelectedValue == "-1")
            {
                scores = -1;
            }

            if (ddlConventions.SelectedIndex > 0 && ddlConventions.SelectedValue != "-1")
            {
                scores += Convert.ToDouble(ddlConventions.SelectedValue);
            }
            else if (ddlConventions.SelectedValue == "-1")
            {
                scores = -1;
            }

            lblScores.Text = scores == -1 ? "" : Convert.ToString(scores);
      }
    }

更新

在内部移动scores和lblScores标签之后，所有内容都按预期工作，除了在任何DropDownList的第一个选择上，除了同一行中的那个，所有其他GridView中的标签值设置为0.为什么会发生这种情况？

先谢谢你的帮助！

Answer 1

每个请求都会将scores变量重置为0（每次更改下拉列表）。然后，您只需将scores设置为当前更改下拉列表的值。如果下拉列表中有选择，您可以做的是获取每个请求的每个下拉列表的值。假设你的下拉每个都将他们的第一个项目设置为＆＃34;选择一个值＆＃34;或者其他什么，您可以检查SelectedIndex是否大于0，如果是，则意味着选择。

foreach (GridViewRow row in gvStuRoster.Rows)
{
    double scores = 0;

    DropDownList ddlFocus = (DropDownList)row.FindControl("ddlFocus");
    DropDownList ddlEvidence = (DropDownList)row.FindControl("ddlEvidence");
    DropDownList ddlConventions = (DropDownList)row.FindControl("ddlConventions");
    Label lblScores = (Label)row.FindControl("lblScores");

    if (ddlFocus.SelectedIndex > 0)
    {
        scores += Convert.ToDouble(ddlFocus.SelectedValue);
    }

    if (ddlEvidence.SelectedIndex > 0)
    {
        scores += Convert.ToDouble(ddlEvidence.SelectedValue);
    }

    if (ddlConventions.SelectedIndex > 0)
    {
        scores += Convert.ToDouble(ddlConventions.SelectedValue);
    }

    lblScores.Text = scores == 0 ? "" : Convert.ToString(scores);
}

Answer 2

在戴夫的帮助下，我得到了我想要的结果。这是我的最终代码：

protected void ddlSelectedIndexChanged(object sender, EventArgs e)
{
    foreach (GridViewRow row in gvStuRoster.Rows)
    {
        double scores = 0;

        DropDownList ddlFocus = (DropDownList)row.FindControl("ddlFocus");
        DropDownList ddlEvidence = (DropDownList)row.FindControl("ddlEvidence");
        DropDownList ddlConventions = (DropDownList)row.FindControl("ddlConventions");
        DropDownList ddlScores = (DropDownList)row.FindControl("ddlScores");
        Label lblScores = (Label)row.FindControl("lblScores");

        if (ddlFocus.SelectedIndex > 0 && ddlFocus.SelectedValue != "-1")
        {
            scores += Convert.ToDouble(ddlFocus.SelectedValue);
        }

        if (ddlEvidence.SelectedIndex > 0 && ddlEvidence.SelectedValue != "-1")
        {
            scores += Convert.ToDouble(ddlEvidence.SelectedValue);
        }

        if (ddlConventions.SelectedIndex > 0 && ddlConventions.SelectedValue != "-1")
        {
            scores += Convert.ToDouble(ddlConventions.SelectedValue);
        }

        ddlScores.SelectedValue = scores == 0 ? "" : Convert.ToString(scores);
    }
}

再次感谢，戴夫！

GridView中DropDownLists值的总和

2 个答案: