C＃字符串串联

Question

Help me with this Problem in C#, im trying to refine the search of my gridview, this is my code, i want to the user to be able to search values with this format on textbox. (name, description) ex. Food, Ice Cream, then it will filter all the food with description of ice cream. Thanks.

((DataTable) gridTestCodes.DataSource).DefaultView.RowFilter = 
        string.Concat("name like '%{0}% + description + '%{0}%'", 
                      txtSearch.Text.Trim().Replace("'", "''"));

Answer 1

You're using concat in place of format . Also, your query is wrong. You're using + instead of AND , there's a single quote missing after first '%{0}% , and description + '%{0}%' doesn't make sense. Try this:

((DataTable)gridTestCodes.DataSource).DefaultView.RowFilter = 
    string.Format("name like '%{0}%' AND description like '%{0}%'", 
                  txtSearch.Text.Trim().Replace("'", "''"));

Or try just querying on name first and then adding in description once this works (also should the .Replace be removing the quotes all together?):

((DataTable)gridTestCodes.DataSource).DefaultView.RowFilter = 
         string.Format("name like '%{0}%'", txtSearch.Text.Trim().Replace("'", string.empty));

EDIT:

If you want to enter name then description seperated by comma try:

var name = txtSearch.Text.Split(',')[0].Trim().Replace("'", string.empty);
var description = txtSearch.Text.Split(',')[1].Trim().Replace("'", string.empty);

((DataTable) gridTestCodes.DataSource).DefaultView.RowFilter = 
        string.Format("name like '%{0}%' AND description like '%{1}%'", name, description);

Note that the above code will throw an exception if the input string does not contain a comma. So you may want to add a check for that.

Answer 2

Looks like you need to use string.Format instead. string.Concat just concatenate your strings, it doesn't format them.

And your expression syntax doesn't seems right. You need one more single quote after your first {0} and you need to use AND or OR between your criterias.

string.Format("name like '%{0}%' AND description like '%{0}%'", 
               txtSearch.Text.Trim().Replace("'", "''"));