Question

此应用程序是留言板类型的应用程序。您发布一条消息，该消息存储在Oracle数据库中。用户的照片，姓名，日期和消息显示在列表视图中。一切正常但是有一个字体颜色变化的功能请求进来了。现在测试下面的东西，我知道我可以将所有消息显示为某种颜色。

我要做的是在表格中添加“颜色”列。然后，如果用户选择他们的消息文本为“红色”，我将在该帖子的表的颜色列中存储红色的十六进制颜色。

所以我想弄清楚的是，当检索到该消息时，如何将此代码设置为'如果颜色列为空，则将消息发布为黑色，否则如果每个消息都存在十六进制颜色，那么特定消息那种颜色'不会像下面的代码那样将每条信息的颜色改为红色。

        List<MsgBoard> Messages = MsgBoard.find_ActiveByBoardName(Convert.ToString(cmbgroup.SelectedItem));
        int i = 0;
        imageList1.Images.Clear();

        foreach (MsgBoard m in Messages)
        {
            AddImages(m.EmpPic);

            ListViewItem Message = new ListViewItem("", i);
            if (m.AlertNo == 0) //Default Message Post (non Alert)
            {
                Message.UseItemStyleForSubItems = false;
                Message.SubItems.Add(m.EmpName.First);
                Message.SubItems.Add(m.MessageText + Environment.NewLine).ForeColor = Color.Red;
                Message.SubItems.Add(m.PostDate.ToString());
                Message.SubItems.Add(m.EmpName.EmpNo.ToString());
                Message.SubItems.Add(m.EmpName.Name);
                listView1.Items.Add(Message);                
            }
            i++;
        }
    }

只是澄清一下。如果20个人发布了一条消息，并且所有20个人都选择了不同的颜色来发布他们的消息。那么在数据库中，所有20行在数据库列中都有不同的颜色，我需要根据他们的颜色分别在列表视图中显示这些消息张贴为。我目前只知道将单一颜色应用于listview中的所有消息，如上例所示。

感谢Stephan，一旦我添加了

Message.SubItems.Add(m.MessageText + Environment.NewLine).ForeColor = System.Drawing.ColorTranslator.FromHtml(m.Color);

然后我需要帮助调整我的查询，以便在颜色列添加颜色后添加颜色。这是代码。

如果DB管理员添加了MESSAGE_COLOR varchar列。

我将以下内容编辑为现有代码，用于发布时新创建的列MESSAGE_COLOR ..

    public string Create()
    {
        try
        {
            OleDbDataReader result = Database.Conn.Execute(
                "INSERT INTO MPCS.MEYER_BOARD (" +
                "EMPLOYEE_ID, " +
                "POST_DATE, " +
                "BOARD_NAME," +
                "ALERT_NO," +
                "MESSAGE_TEXT," +
                "MESSAGE_COLOR," +
                "ACTIVE_FLAG" +
                ") VALUES (?,SYSDATE,?,?,?,?)",
                new List<OleDbParameter> {
                     new OleDbParameter("EMPLOYEE_ID",EmpName.EmpNo),
                     new OleDbParameter("BOARD_NAME",BoardName),
                     new OleDbParameter("ALERT_NO",AlertNo),
                     new OleDbParameter("MESSAGE_TEXT",MessageText),
                     new OleDbParameter("MESSAGE_COLOR",MessageColor),
                     new OleDbParameter("ACTIVE_FLAG",ActiveFlag ? "Y" : "N")
                    }, Query.ReaderType.Reader);
            result.Read();
            result.Close();
            return null;
        }
        catch (Exception ex)
        {
            return ex.Message;
        }
    }

然后我也用新列编辑DB读取。

public static MsgBoard DBRead(OleDbDataReader result,string alias=null)
    {
        return new MsgBoard
        {
            EmpName = Employee.DBRead(result, "EMPLOYEE"),
            MessageText = result[alias + "MESSAGE_TEXT"].ToString(),
            MessageColor = result[alias + "MESSAGE_COLOR"].ToString(),
            BoardName = result[alias +"BOARD_NAME"].ToString(),
            AlertNo = (int)(decimal)result[alias +"ALERT_NO"],
            PostDate = (DateTime)result[alias +"POST_DATE"],
            ActiveFlag = result[alias +"ACTIVE_FLAG"].ToString().ToString() == "Y",
            EmpPic = ImageResource.DBRead(result, "IR")
        };
    }

但是我需要编辑我的build_query吗？

    public static String build_query(String where, string OrderBy = null)
    {
        List<String> cols = new List<String>();
        cols.AddRange(db_columns.ConvertAll(c => "MPCS.MEYER_BOARD." + c + " AS MBOARD_" + c));
        cols.AddRange(Employee.db_columns.ConvertAll(c => "MPCS.EMPLOYEE." + c + " AS EMPLOYEE_" + c));
        cols.AddRange(ImageResource.db_columns.ConvertAll(c => "MPCS.IMAGE_RESOURCE." + c + " AS IR_" + c));
        String sql =
            "SELECT " + String.Join(", ", cols) + " " +
            "FROM MPCS.MEYER_BOARD " +
            "LEFT OUTER JOIN MPCS.EMPLOYEE " +
            "ON MPCS.MEYER_BOARD.EMPLOYEE_ID=MPCS.EMPLOYEE.EMPLOYEE_ID " +
            "LEFT OUTER JOIN MPCS.IMAGE_RESOURCE " +
            "ON MPCS.IMAGE_RESOURCE.IR_ID=MPCS.EMPLOYEE.IMAGE_RESOURCE_ID " +
        "WHERE ";
        sql += where;
        sql += OrderBy;
        return sql;
    }

更新

我已经完成了所有编码，现在我正在向DB提交颜色。但是，当在每个帖子下方显示列表视图时，仍然只有默认的黑色文本颜色。而不是保存的颜色，例如“＃FFF000”被转换和显示。

foreach (MsgBoard m in Messages)
        {
            AddImages(m.EmpPic);

            ListViewItem Message = new ListViewItem("", i);
            if (m.AlertNo == 0) //Default Message Post (non Alert)
            {
                Message.SubItems.Add(m.EmpName.First);                   
                Message.SubItems.Add(m.MessageText + Environment.NewLine).ForeColor = System.Drawing.ColorTranslator.FromHtml(m.MessageColor);
                Message.SubItems.Add(m.PostDate.ToString());
                Message.SubItems.Add(m.EmpName.EmpNo.ToString());
                Message.SubItems.Add(m.EmpName.Name); //Displayed only on 'Show Details'
                listView1.Items.Add(Message);
            }

最终更新

原来我遗失的最后一块是改变listview属性UseItemStyleForSubItems = false;现在它的工作。

Answer 1

You can convert your hex value (assuming that it is stored as a string in the format "#RRGGBB") into a color using ColorTranslator
Using this approach, you can also use named colors (like "Violet")

Message.SubItems.Add(m.MessageText + Environment.NewLine).ForeColor =  
    System.Drawing.ColorTranslator.FromHtml(m.Color); //sth. like "#FFCC66"

Furthermore you have to retrieve the value of the Color column. It seems that you have to add "MESSAGE_COLOR" (or whatever your column is called) to your db_columns. When you got the values from the DB, you have to map the column to the property of your Message:

return new MsgBoard
{
  // ...
  Color = System.Drawing.ColorTranslator.FromHtml([alias+"MESSAGE_COLOR"]),
  // ...
}

(In other words: You already save it to db, now you also have to read it from DB)

Listview ForeColor每个项目

1 个答案: