我有這個搜索功能,爲了標記來自MySQL數據庫的匹配關鍵字列表的評論,標記的評論將顯示在dataGridView_flaggedComments
上,然後關注通過填入comboBox_stockIndex
與涉及的股價符號(例如BARC,LLOY,TSCO)。「對象引用未設置爲對象的實例」時過濾dataGridView
private void button_Search1_Click(object sender, EventArgs e)
{
commentCount = 0;
dataGridView_flaggedComments.Refresh();
DataTable flaggedcomments = new DataTable("flaggedcomments");
using (MySqlConnection sqlConn = new MySqlConnection(strProvider))
{
using (MySqlDataAdapter da = new MySqlDataAdapter("SELECT Comment_ID, Comments_Date, Comments_Time, Author, Title, Comments_Comment, Tickers_Ticker_ID FROM comments ORDER BY Comments_Date ASC, Comments_Time ASC", sqlConn))
{
da.Fill(flaggedcomments);
}
}
StringBuilder sb = new StringBuilder();
string[] words = File.ReadAllLines(sourceDirTemp + comboBox_crimeKeywords.SelectedItem.ToString() + ".txt");
var query = flaggedcomments.AsEnumerable().Where(r => words.Any(wordOrPhrase => Regex.IsMatch(r.Field<string>("Comments_Comment"), @"\b" + Regex.Escape wordOrPhrase) + @"\b", RegexOptions.IgnoreCase)));
dataGridView_flaggedComments.DataSource = query.AsDataView();
PopulateStockIndex();
}
private void PopulateStockIndex()
{
comboBox_stockIndex.Items.Clear();
comboBox_stockIndex.Items.Add("Choose to Filter");
DataTable link_stockIndex = new DataTable("link_stockIndex");
using (MySqlConnection sqlConn = new MySqlConnection(strProvider))
{
using (MySqlDataAdapter da = new MySqlDataAdapter("SELECT Ticker_ID, Symbol FROM tickers", sqlConn))
{
da.Fill(link_stockIndex);
}
}
foreach (DataRow da in link_stockIndex.Rows)
{
for (int i = 0; i < dataGridView_flaggedComments.Rows.Count - 1; i++)
{
if (dataGridView_flaggedComments.Rows[i].Cells["Tickers_Ticker_ID"].Value.ToString() != "" && dataGridView_flaggedComments.Rows[i].Cells["Tickers_Ticker_ID"].Value.ToString() == da["Ticker_ID"].ToString())
{
if (!comboBox_stockIndex.Items.Contains(da[1].ToString()))
{
comboBox_stockIndex.Items.Add(da[1].ToString());
}
comboBox_stockIndex.SelectedIndex = 0;
}
}
}
}
接下來,如果我選擇從comboBox_stockIndex
象徵,dataGridView_flaggedComments
應該過濾,只顯示相關選定的符號(一旦選擇符號,它會尋找符號的Tickers_TTicker_ID,然後通過過濾評論Tickers_Ticker_ID)。但下面的代碼不起作用。有一個錯誤說「對象引用未設置爲對象的實例」。對於這條線(dataGridView_flaggedComments.DataSource as DataTable).DefaultView.RowFilter = string.Format("Tickers_Ticker_ID = '{0}'", da["Ticker_ID"]);
。我試圖調試,但我不明白哪裏出了問題。
private void comboBox_stockIndex_SelectedIndexChanged(object sender, EventArgs e)
{
DataTable link_stockIndex = new DataTable("link_stockIndex");
using (MySqlConnection sqlConn = new MySqlConnection(strProvider))
{
using (MySqlDataAdapter da = new MySqlDataAdapter("SELECT Ticker_ID, Symbol FROM tickers", sqlConn))
{
da.Fill(link_stockIndex);
}
}
foreach (DataRow da in link_stockIndex.Rows)
{
for (int i = 0; i < dataGridView_flaggedComments.Rows.Count - 1; i++)
{
if (dataGridView_flaggedComments.Rows[i].Cells["Tickers_Ticker_ID"].Value.ToString() != "" && comboBox_stockIndex.SelectedItem.ToString() == da["Symbol"].ToString())
{
(dataGridView_flaggedComments.DataSource as DataTable).DefaultView.RowFilter = string.Format("Tickers_Ticker_ID = '{0}'", da["Ticker_ID"]);
}
}
}
}
我已經花了兩天的時間研究這個,SOF是我的最後一招。任何幫助將非常感謝!非常感謝你!
好吧,我不能相信這只是'DataView'和'DataTable'的問題! T.T現在可以使用!非常感謝你!! :D – Shyuan 2014-10-28 13:00:04
我不能相信你花了2天的時間:) – Reniuz 2014-10-28 13:11:13
我也是.. :(另外,這是因爲編程不是我學到的東西,而是我爲我的項目做了部分工作:/ – Shyuan 2014-10-28 13:20:19