DropDownList数据绑定第一项为空
本文章转之http://kay.cnblogs.com
我们在进行数据绑定时通常把一个表的某个字段绑定到DropDownList中,我们以pubs库的jobs表为例子,我们在显示时显示job_desc字段,values值绑定job_id字段。
方法一:
使用属性设置,我们在DropDownList的items的属性中添加一列为空行,然后更改AppandBataBoundItems属性为ture.
绑定代码:
绑定代码
![](https://www.cnblogs.com/images/cnblogs_com/kay/11.gif)
![](https://www.cnblogs.com/images/cnblogs_com/kay/12.gif)
这样就可以了。
方法二:
使用代码:
我们在进行数据绑定时通常把一个表的某个字段绑定到DropDownList中,我们以pubs库的jobs表为例子,我们在显示时显示job_desc字段,values值绑定job_id字段。
方法一:
使用属性设置,我们在DropDownList的items的属性中添加一列为空行,然后更改AppandBataBoundItems属性为ture.
绑定代码:
![](https://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif)
![](https://www.cnblogs.com/images/cnblogs_com/kay/11.gif)
![](https://www.cnblogs.com/images/cnblogs_com/kay/12.gif)
这样就可以了。
方法二:
使用代码:
1![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
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SqlConnection conn = new SqlConnection("server=.;uid=sa;database=pubs");
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SqlDataAdapter dap = new SqlDataAdapter("select * from jobs", conn);
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DataTable dt = new DataTable();
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dap.Fill(dt);
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DropDownList1.Items.Clear();
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DropDownList1.DataSource = dt;
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DropDownList1.DataTextField = "job_desc";
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DropDownList1.DataValueField = "job_id";
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DropDownList1.DataBind();
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DropDownList1.Items.Insert(0, new ListItem("", ""));//插入空项,此举必须放到数据绑定之后
效果:![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
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![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/images/cnblogs_com/kay/13.gif)