我用asp.net(C#)做的在线考试系统,但是就是取不到考生的答案?抽提的源码是:
Label lit_testContent = new Label();
RadioButtonList rbtnList = new RadioButtonList(); rbtnList.ID = "rbtnList" + number.ToString();
lit_testContent.Text = number.ToString () + "、" + conn.dr["itemname"].ToString() ;
rbtnList.Items .Add("A. " + conn.dr["optiona"].ToString());
rbtnList.Items .Add("B. " + conn.dr["optionb"].ToString());
rbtnList.Items .Add("C. " + conn.dr["optionc"].ToString());
rbtnList.Items .Add("D. " + conn.dr["optiond"].ToString()); rbtnList.Items[0].Value = "A";
rbtnList.Items[1].Value = "B";
rbtnList.Items[2].Value = "C";
rbtnList.Items[3].Value = "D";
Panel1.Controls.Add(lit_testContent);
Panel1.Controls.Add(rbtnList);
这段代码能抽到提!下面是取考生答案的源码:
string ans = "";
for (int i = 2; i <= 10; i++)
{
RadioButtonList list ; list = (RadioButtonList)Panel1.FindControl("rbtnList" + i.ToString()); if (list != null)
{
ans = list.SelectedValue.ToString(); ht_stuAnswer.Add(i.ToString(), ans); this.Label1.Text = ans;
else
{
ans += i.ToString() + "null";
}
}但是这段代码不能取到值,不加 if (list != null)的话提示 ”未将对象引用设置到对象的实例“
也就是list 总是null.各位大哥大姐,怎么办?很急的!真诚期待中。。
Label lit_testContent = new Label();
RadioButtonList rbtnList = new RadioButtonList(); rbtnList.ID = "rbtnList" + number.ToString();
lit_testContent.Text = number.ToString () + "、" + conn.dr["itemname"].ToString() ;
rbtnList.Items .Add("A. " + conn.dr["optiona"].ToString());
rbtnList.Items .Add("B. " + conn.dr["optionb"].ToString());
rbtnList.Items .Add("C. " + conn.dr["optionc"].ToString());
rbtnList.Items .Add("D. " + conn.dr["optiond"].ToString()); rbtnList.Items[0].Value = "A";
rbtnList.Items[1].Value = "B";
rbtnList.Items[2].Value = "C";
rbtnList.Items[3].Value = "D";
Panel1.Controls.Add(lit_testContent);
Panel1.Controls.Add(rbtnList);
这段代码能抽到提!下面是取考生答案的源码:
string ans = "";
for (int i = 2; i <= 10; i++)
{
RadioButtonList list ; list = (RadioButtonList)Panel1.FindControl("rbtnList" + i.ToString()); if (list != null)
{
ans = list.SelectedValue.ToString(); ht_stuAnswer.Add(i.ToString(), ans); this.Label1.Text = ans;
else
{
ans += i.ToString() + "null";
}
}但是这段代码不能取到值,不加 if (list != null)的话提示 ”未将对象引用设置到对象的实例“
也就是list 总是null.各位大哥大姐,怎么办?很急的!真诚期待中。。
没有找到控件。
看看它是不是取到了"你要的控件",如果取到了,再看它的类型是不是能够正常转化为(RadioButtonList)
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还有一个问题就是: 怎么做倒计时啊??比如说考试30分钟。倒计时到0分0秒时自动交卷!还有网页过期时间,Sesson 怎么设??