如何解决Gridview 单元格颜色需要根据在 asp.net/c# 中检查的 CheckBox 进行更改不断收到错误
我有一个 Gridview (ASP.NET / C#),它当前根据用户提供的日期改变颜色。过期日期为红色,未来或当前日期为白色(效果很好!)。我还在 gridview 单元格中提供了一个复选框,指定“完成”。如果选中该复选框,我希望它覆盖日期并将单元格颜色更改为黑色。到目前为止,我不断收到的错误是,当我在“RowDataBound”下尝试时对象未设置为对象的实例,或者现在使用当前代码,我尝试将其放在“OnCheckedChanged”下,现在已阻止任何更改到复选框。
数据以 Bit 的形式存储在数据库中。更新命令将参数设置为布尔值。
关于如何让它发挥作用的任何想法?
ASP.NET 标记:
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSource1"
GridView1_RowUpdating="true" DataKeyNames="ID" OnRowUpdating="Page_Load"
BackColor="#CCCCCC" BorderColor="#999999" BorderStyle="Solid"
BorderWidth="3px" CellPadding="4" CellSpacing="2" ForeColor="Black"
OnRowDataBound="GridView1_RowDataBound">
<Columns>
<asp:TemplateField HeaderText="Verify Info Prod & Maturity Level" SortExpression="IPMaturity">
<EditItemTemplate>
<asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("IPMaturity","{0:MM/dd/yyyy}") %>' Width="75"></asp:TextBox>
<asp:CheckBox ID="CheckBox1" runat="server" AutoPostBack="true" Text="Complete" Enabled="false" OnCheckedChanged="CheckBox1_CheckedChanged"
Checked='<%# Bind ("CheckBox1") %>'></asp:CheckBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="lblIPMat" runat="server" Text='<%# Eval("IPMaturity","{0:MM/dd/yyyy}") %>' Width="75"></asp:Label>
</ItemTemplate>
<HeaderStyle CssClass="verticaltext" Height="140px" Width="88px" HorizontalAlign="Center" VerticalAlign="Bottom" />
</asp:TemplateField>
背后的C#代码:
protected void CheckBox1_CheckedChanged(object sender,EventArgs e) //from checkbox
{
CheckBox chkItem = null;
//Boolean chkb = Convert.ToBoolean(DataBinder.Eval(e.Row.DataItem,"CheckBox1"));
foreach (GridViewRow grRow in GridView1.Rows)
{
if (grRow.RowType == DataControlRowType.DataRow)
{
chkItem = (CheckBox)grRow.Cells[4].FindControl("CheckBox1");
bool bl = chkItem.Checked;
if (bl == true)
{
grRow.BackColor = Color.Black;
}
}
}
}
protected void GridView1_RowDataBound(object sender,GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow) // Changes color of cell based on date
{
string ipMaturity = Convert.ToString(DataBinder.Eval(e.Row.DataItem,"IPMaturity"));
DateTime? date1 = !string.IsNullOrEmpty(ipMaturity) ? Convert.ToDateTime(ipMaturity) : (DateTime?)null;
if (date1.HasValue && date1 >= DateTime.Now)
e.Row.Cells[4].BackColor = System.Drawing.Color.White;
if (date1.HasValue && date1 < DateTime.Now)
e.Row.Cells[4].BackColor = System.Drawing.Color.Red;
}
}
解决方法
保留尽可能多的代码,我制作了一个最低限度的示例来显示复选框更改背景颜色。
需要指出的是,上面的代码示例没有 Cells[4]
(所以我刚刚使用了 0)。我已经用类 (IPMaturityData) 和硬编码数据替换了 SQL 调用。没有调用启用 EditItemTemplate
,所以我只是继续添加 <asp:CommandField ShowEditButton="True" />
代码不会为您提供所需的一切。然而,它应该足以发挥作用并使其按预期工作。
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
GridView1_RowUpdating="true" DataKeyNames="ID" OnRowUpdating="Page_Load"
BackColor="#CCCCCC" BorderColor="#999999" BorderStyle="Solid"
BorderWidth="3px" CellPadding="4" CellSpacing="2" ForeColor="Black"
OnRowEditing="GridView1_RowEditing"
OnRowDataBound="GridView1_RowDataBound">
<Columns>
<asp:TemplateField>
<EditItemTemplate>
<asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("IPMaturity","{0:MM/dd/yyyy}") %>' Width="75"></asp:TextBox>
<asp:CheckBox ID="CheckBox1"
runat="server"
AutoPostBack="true"
Text="Complete"
OnCheckedChanged="CheckBox1_CheckedChanged"
Checked='<%# Bind ("CheckBox1") %>'></asp:CheckBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="lblIPMat" runat="server" Text='<%# Eval("IPMaturity","{0:MM/dd/yyyy}") %>' Width="75"></asp:Label>
</ItemTemplate>
<HeaderStyle CssClass="verticaltext" Height="140px" Width="88px" HorizontalAlign="Center" VerticalAlign="Bottom" />
</asp:TemplateField>
<asp:CommandField ShowEditButton="True" />
</Columns>
</asp:GridView>
背后的代码:
protected void Page_Load(object sender,EventArgs e)
{
if (!Page.IsPostBack)
{
this.DataBindGrid();
}
}
protected void GridView1_RowEditing(object sender,GridViewEditEventArgs e)
{
GridView grid = sender as GridView;
if (grid == null)
{
return;
}
grid.EditIndex = e.NewEditIndex;
this.DataBindGrid();
}
protected void GridView1_RowDataBound(object sender,GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow) // Changes color of cell based on date
{
string ipMaturity = Convert.ToString(DataBinder.Eval(e.Row.DataItem,"IPMaturity"));
DateTime? date1 = !string.IsNullOrEmpty(ipMaturity) ? Convert.ToDateTime(ipMaturity) : (DateTime?)null;
if (date1.HasValue && date1 >= DateTime.Now)
e.Row.Cells[0].BackColor = System.Drawing.Color.White; // Theres no cell 4
if (date1.HasValue && date1 < DateTime.Now)
e.Row.Cells[0].BackColor = System.Drawing.Color.Red;
}
}
protected void CheckBox1_CheckedChanged(object sender,EventArgs e) //from checkbox
{
foreach (GridViewRow grRow in GridView1.Rows)
{
if (grRow.RowType == DataControlRowType.DataRow)
{
CheckBox chkItem = (CheckBox)sender;
// chkItem = (CheckBox)grRow.Cells[4].FindControl("CheckBox1"); // This would work if cell 4 has a CheckBox
if (chkItem.Checked)
{
grRow.BackColor = Color.Black;
}
}
}
}
private void DataBindGrid()
{
var x = new List<IPMaturityData>();
x.Add(new IPMaturityData() { ID = 1,IPMaturity = DateTime.Now.AddDays(-1) });
x.Add(new IPMaturityData() { ID = 2,IPMaturity = DateTime.Now.AddDays(1) });
GridView1.DataSource = x;
GridView1.DataBind();
}
public class IPMaturityData
{
public int ID { get; set; }
public DateTime IPMaturity { get; set; }
public bool CheckBox1 { get; set; } // This looks wrong,but on html it has "Checked='<%# Bind ("CheckBox1") %>"
}
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