沒有超載的方法'TryParse'需要'1'參數

Question

其實我試圖插入以及更新數據到datagridview在運行時，我寫了一個代碼，但執行它時給我數據類型沒有重載的方法'的TryParse」拍攝‘1’參數
我ACCDB表結構是像下面

Field Datatype 
Account-- Memo 
AccountNumber--Number 
Date--Date/Time 
Description--Memo 
Post_Ref--Memo 
Debit--Number 
Credit--Number 
Balance--Number 

**

 private void dataGridView1_CellValueChanged(object sender, DataGridViewCellEventArgs e) 
     { 
     string connectionString = null; 
        connectionString = ConfigurationManager.ConnectionStrings["AccessConnectionString"].ConnectionString; 
        con.ConnectionString = connectionString; 

        string cmd1 = "insert into Ledger([AccountNumber],[Account],[Date],[Description],[Post_Ref],[Debit],[Credit],[Balance])values(?,?,?,?,?,?,?,?)"; 
        OleDbCommand cmd = new OleDbCommand(cmd1, con); 
        con.Open(); 
        cmd.CommandType = CommandType.Text; 
int accountNumber; 

        bool accountHasValue = int.TryParse(dataGridView1.Rows[e.RowIndex].Cells["AccountNumber"].Value.ToString(), out accountNumber); 

        if (accountHasValue) 
        { 
         cmd.Parameters.AddWithValue("@AccountNumber", accountNumber); 
        } 

        string accounts = dataGridView1.Rows[e.RowIndex].Cells["Account"].Value.ToString(); 
        cmd.Parameters.AddWithValue("@Account", accounts); 

        DateTime datetime; 
        bool dateTimeHasValue = DateTime.TryParse(dataGridView1.Rows[e.RowIndex].Cells["Date"].Value.ToString(), out datetime); 

        if (dateTimeHasValue) 
        { 
         cmd.Parameters.AddWithValue("@Date", datetime); 
        } 


        string Description = dataGridView1.Rows[e.RowIndex].Cells["Description"].Value.ToString(); 
        cmd.Parameters.AddWithValue("@Description", Description); 


        string Post_Ref = dataGridView1.Rows[e.RowIndex].Cells["Post_Ref"].Value.ToString(); 
        cmd.Parameters.AddWithValue("@Post_Ref", Post_Ref); 


        int debit; 
        bool debitHasValue = Int32.TryParse(dataGridView1.Rows[e.RowIndex].Cells["Debit"].Value.ToString(), out debit); 

        if (debitHasValue) 
        { 
         cmd.Parameters.AddWithValue("@Debit", debit); 
        } 


        int Credits; 
        bool CreditsHasValue = Int32.TryParse(dataGridView1.Rows[e.RowIndex].Cells["Credit"].Value.ToString(), out Credits); 

        if (CreditsHasValue) 
        { 
         cmd.Parameters.AddWithValue("@Credit", Credits); 
        } 

        int Balances; 
        bool BalancesHasValue = Int32.TryParse(dataGridView1.Rows[e.RowIndex].Cells["Balance"].Value.ToString(), out Balances); 

        if (BalancesHasValue) 
        { 
         cmd.Parameters.AddWithValue("@Balance", Balances); 
        } 


        cmd.ExecuteNonQuery(); 


        con.Close(); 

        Load_data(); 
} 

Answer 1

誤差僅僅意味着的TryParse方法不具有接受一個參數的過載。如果您查看documentation，則需要兩個參數。

對於使用TryParse的代碼行，首先聲明一個變量並將其用作out參數並將其傳遞給種子數據庫。讓我看看代碼!!!好的，看下面的例子。

//For accountNumber 
int accountNumber; 

bool accountHasValue = int.TryParse(dataGridView1.Rows[e.RowIndex].Cells["AccountNumber"].Value, out accountNumber); 

if(accountHasValue) 
{ 
    cmd.Parameters.AddWithValue("@AccountNumber", accountNumber); 
} 

//For Datetime 
DateTime datetime; 
bool dateTimeHasValue = DateTime.TryParse(dataGridView1.Rows[e.RowIndex].Cells["Date"].Value, out datetime); 

if(dateTimeHasValue) 
{ 
    cmd.Parameters.AddWithValue("@Date", datetime); 
} 

//For Debit 
int debit; 
bool debitHasValue = Int32.TryParse(dataGridView1.Rows[e.RowIndex].Cells["Debit"].Value, debit); 

if(debitHasValue) 
{ 
    cmd.Parameters.AddWithValue("@Debit", debit); 
} 

基本上，您使用TryParse的所有代碼行都按上述方式實現。