指定的转换类型无效错误C＃请帮助 [英] Specified Cast Type not Valid Error C# please help

问题描述

我正在尝试从数据库中将一些值插入到图表中。第一列（X轴）是String类型，第二列（Y轴）是float类型。当我按下按钮时，我不断收到此错误Cast Type无效。请帮助

I am trying to insert some values into a chart from a database. the first column (X axis) is a String type and the second column ( Y Axis) is float type. I keep getting this error "Cast Type not valid"when ever i press the button. Please help

private void ViewGraphBtn_Click(object sender, EventArgs e)
  {
      try
      {
          Query = "SELECT *  FROM Products;";
          Reader = conn.ExecuteStatement(Query);

          while (Reader.Read())
          {
              this.chart1.Series["Series1"]
                         .Points.AddXY(Reader.GetString(1), Reader.GetInt64(4));
          }
      }
      catch (Exception ex)
      {
           MessageBox.Show(ex.Message);
      }

推荐答案

X和Y都需要是数值。字符串不是图表控制点的有效类型。

X and Y both need to be numeric values. A string is not a valid type for a chart control point.

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