ASP中数据的动态表示.网络应用程序
本文关键字：表示 网络 应用程序 动态 数据 ASP | 更新日期: 2023-09-27 18:18:58
我一直在试图找出一种动态呈现数据的方法，但一直没有运气。我有一个警报系统(由一个SQL Server DB表组成)，然后我想要在该表中的每个(相关)行，构建一个字符串在ASP页面中呈现，也插入一个复选框(只是这样我就可以将警报标记为"读取")。
我已经有了数据和所有(我认为我做的是正确的)，但已经完全无法以我想要的方式在页面上呈现这些数据。
下面是c#代码:protected void getAlertas(string matricula)
{
string query = "SELECT * FROM ALERTAS A ";
query += "WHERE EXISTS ( ";
query += "SELECT ID, MATRICULA FROM VEICULOS V WHERE V.MATRICULA = @matricula ";
query += "AND A.IDVEICULO = V.ID ";
query += "AND LIDA = 0)";
SqlCommand comm = new SqlCommand(query, Utils.connectDB());
matricula = matricula.ToString().Replace("'"", "'");
comm.Parameters.AddWithValue("@matricula", matricula);
StringBuilder builder = new StringBuilder();
DataTable dt = new DataTable();
SqlDataAdapter da = new SqlDataAdapter();
StringCollection alertValues = new StringCollection();
StringBuilder HTML = new StringBuilder();
try
{
comm.Connection.Open();
SqlDataReader reader = comm.ExecuteReader();
dt.Load(reader);
foreach (DataRow row in dt.Rows)
{
Label label = new Label();
CheckBox cBox = new CheckBox();
foreach (DataColumn column in dt.Columns)
{
alertValues.Add(row[column].ToString());
}
builder.Append(alertValues[0]); //ID do alerta
builder.Append(":");
builder.Append(matricula);
if (int.Parse(alertValues[10]) == 0) //se motor desligado
{
//string output = "Motor desligado às " + alertValues[3] + "do dia " + alertValues[4];
builder.Append("Motor desligado às ");
}
else if(int.Parse(alertValues[10]) == 1) //se motor ligado
{
//string output = "Motor ligado às " + alertValues[3] + "do dia " + alertValues[4];
builder.Append("Motor ligado às ");
}
builder.Append(alertValues[3]); //hora
builder.Append("do dia ");
builder.Append(alertValues[4]); //data
//HTML.Append(" <div id='"notifications'" runat='"server'" class='"notifications'">");
//HTML.Append(" <div class='"notificationText'">");
//HTML.Append("<asp:Label ID='"Label1'" runat='"server'" Text='"" + builder.ToString() + "'"></asp:Label>");
//HTML.Append("</div>");
//HTML.Append("<div class='"setRead'">");
//HTML.Append("<asp:CheckBox ID='"" + alertValues[0] + "'" runat='"server'" />");
//HTML.Append("</div>");
//HTML.Append("</div>");
label.Text = builder.ToString();
cBox.ID = alertValues[0];
}
}
finally
{
comm.Connection.Close();
}
}
这是我要展示数据的ASP页面:
<div id="contentRight">
<div id="head">
<p>
<b>Notificações</b></p>
</div>
<div id="notifications" runat="server" class="notifications">
<div class="notificationText">
<asp:Label ID="Label1" runat="server" Text="Nada para mostrar"></asp:Label>
</div>
<div class="setRead">
<asp:CheckBox ID="AlertIDRead" runat="server" />
</div>
</div>
<hr />
<div id="OkBtn" align="center">
<asp:Button ID="OkButton" class="Button" runat="server" Text="Ok" />
</div>
</div>
目标是能够将构造的字符串呈现给页面，并且对于每一行，还提供一个CheckBox，该CheckBox将具有与alertID(在DB上)相同的ID，只是为了简单地将它们标记为已读。
我真的迷路了，需要一些帮助。
您可以动态地添加条目。然而，这有点痛苦。您必须每次都添加它们，而不仅仅是第一次加载页面。此外，如果你想在回发之间保留视图状态并记住哪些框被选中，你需要在页面生命周期的早期添加它们(例如在Page_Init事件中)。
一个更简单的方法是使用一个控件，比如ListView。在ASP。你可以很容易地得到你想要的控件名，但是你可能会对ASP中自动生成的控件名感到满意。NET 3.5。下面是一个ASPX页面的示例:
<asp:ListView runat="server" ID="listView" DataKeyNames="AlertId">
<LayoutTemplate>
<div id="contentRight">
<div id="head">
<p>
<b>Notificações</b></p>
</div>
<div id="notifications" runat="server" class="notifications">
<asp:PlaceHolder ID="itemPlaceholder" runat="server" />
</div>
</div>
</LayoutTemplate>
<ItemTemplate>
<div class="notificationText">
<asp:Label ID="Label1" runat="server" Text='<%#Eval("AlertText")%>' />
</div>
<div class="setRead">
<asp:CheckBox ID="AlertChecked" runat="server" />
</div>
</ItemTemplate>
</asp:ListView>
<hr />
<div id="OkBtn" align="center">
<asp:Button ID="OkButton" class="Button" runat="server" Text="Ok" onclick="OkButton_Click" />
</div>
<asp:Label runat="server" ID="lblDisplay" />
下面是一些示例代码。注意，我已经用硬编码列表替换了数据访问代码。我假设您可以将其替换为从数据库加载数据所需的代码。
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
// Creates a list of alerts and binds them to the list view.
// You would use your sql data reader here instead. You could convert the data
// into a list or just bind the data reader directly to the list view. If you
// bind the data reader to the list view then be sure to update the Eval statements
// in the list view templates.
var alerts = new[]
{
new { AlertId = 1, AlertText = "This is alert #1."},
new { AlertId = 2, AlertText = "This is the second alert."},
new { AlertId = 3, AlertText = "This is the third alert."},
new { AlertId = 5, AlertText = "This is alert #5."}
};
listView.DataSource = alerts;
listView.DataBind();
}
}
protected void OkButton_Click(object sender, EventArgs e)
{
// get the list of alerts that have been checked
var checkedAlerts = new List<int>();
foreach (var listViewItem in listView.Items)
{
var checkbox = (CheckBox)listViewItem.FindControl("AlertChecked");
if (checkbox.Checked)
{
checkedAlerts.Add((int)listView.DataKeys[listViewItem.DataItemIndex].Value);
}
}
// now do something to record them as read; we'll just display them in a label for this sample.
lblDisplay.Text = "The following alerts were marked read: " + String.Join(",", checkedAlerts);
}