c# - Arabic turn to strange Question marks -

after typing in arabic in form press insert button insert fields in db. characters turn strange question marks :"?????". doesn't happen numbers or english characters.

how type arabic , still have in db arabic, not "?????"?

here code

sqlconnection cn = new sqlconnection(system.configuration.configurationmanager.connectionstrings["storeconnectionstring"].tostring());          public addbook()         {             initializecomponent();         }          private void button1_click(object sender, eventargs e)         {                 string x;                 cn.open();                 sqlcommand cm = new sqlcommand("select count(*) storeitem", cn);                 int32 count = (int32)cm.executescalar();                 x = count.tostring();                 cn.close();                  sqlcommand cmd = new sqlcommand("insert storeitem (id, title, writer, price, qun, date) values ('" + x + "','" + textbox1.text + "', '" + textbox2.text + "', '" + textbox3.text + "', '" + textbox4.text + "', '" + datetime.now.tostring("d/m/yyyy") + "')", cn);                 cn.open();                 cmd.executenonquery();                 cn.close();                  textbox1.text = null;                 textbox2.text = null;                 textbox3.text = null;                 textbox4.text = null;                  this.close();         }          private void button2_click(object sender, eventargs e)         {             this.close();         } 

and

private void rsh() {     sqldataadapter adap = new sqldataadapter("select * storeitem", cn);     dataset ds = new dataset();     adap.fill(ds, "store");     datagridview1.datasource = ds.tables["store"];     datagridview1.columns[1].width = 200;     datagridview1.columns[0].headercell.value = "#";     datagridview1.columns[1].headercell.value = "عنوان الكتاب";     datagridview1.columns[2].headercell.value = "الكاتب";     datagridview1.columns[3].headercell.value = "السعر";     datagridview1.columns[4].headercell.value = "الكمية";     datagridview1.columns[5].headercell.value = "تاريخ دخول"; } 

surly datatype column varchar.

you need change nvarchar , saved. dont forget add prefix n. refer following query.

if name nvarchar

insert emp (name) values (n'test')