获取数据表中的值指数

本文介绍了获取数据表中的值指数的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我需要得到一个价值指数在数据表。

i need to get index of a value in DataTable.

我试图让这样的。

SqlDataAdapter da = new SqlDataAdapter("SELECT MessageID,SenderID,MessageContent FROM Messages WHERE ThreadID="+ThreadID, connectionString); //Get all messages in the Thread. DataTable dt = new DataTable(); da.Fill(dt); da.SelectCommand.CommandText = "SELECT MessageID,SenderID,MessageContent FROM Messages WHERE MessageID="+MessageID; //Get the message which i need to get index. DataTable dtMsg = new DataTable(); da.Fill(dtMsg); //Get index of dtMsg.Rows[0] in dt. int msgIndex = dt.Rows.IndexOf(dtMsg.Rows[0]);

我analized它时，调试值相同，但其返回-1每次。我该怎么办？

I analized it when debugging values are same but its returning -1 everytime. What i can do?

推荐答案

您正在寻找在数据表DT行时该行实际上是在数据表dtMsg ....

You are looking for a row in datatable dt when the row is actually in datatable dtMsg....

尝试：

int msgIndex = dtMsg.Rows.IndexOf(dtMsg.Rows[0]);

其实这总是会返回零反正你是用索引引用无论如何行。

Actually that is always going to return zero anyway as you are referencing the row by index anyway.

如果你真正想要的是DT找到一排基于在dtMsg行中的值，你需要使用像查找（）或选择（）。

If what you actually want is to find a row in dt based on a value in a dtMsg row you will need to use something like Find() or Select().

继承人是一些示例code：

Heres's some sample code:

// Create test data table with messageid as primary column DataTable dt = new DataTable(); dt.Columns.Add("MessageID", typeof (int)); dt.Columns.Add("SenderID", typeof(int)); dt.Columns.Add("MessageContent", typeof(string)); dt.PrimaryKey = new[] {dt.Columns["MessageID"]}; // Add some data dt.Rows.Add(1, 10, "Message1"); dt.Rows.Add(2, 11, "Message2"); dt.Rows.Add(3, 12, "Message3"); dt.Rows.Add(4, 13, "Message4"); // Create second test data table with single row DataTable dtMsg = new DataTable(); dtMsg.Columns.Add("MessageID", typeof(int)); dtMsg.Columns.Add("SenderID", typeof(int)); dtMsg.Columns.Add("MessageContent", typeof(string)); dtMsg.PrimaryKey = new[] { dtMsg.Columns["MessageID"] }; dtMsg.Rows.Add(3, 12, "Message3"); // Not very elegant way of getting the message id from dtMsg. int messageId = (int)dtMsg.Rows[0][0]; int index = dt.Rows.IndexOf(dt.Rows.Find(messageId)); // Result : index is 2 Console.WriteLine(index);

这个假设的MessageId是餐桌上的主索引。

This assumes that MessageId is the primary index on the table.