如何在catch塊中獲取變量名？

Question

在這里，我分配了多個string變量，但我想捕獲哪個變量及其名稱的錯誤。

try
{
    sSrNo = Convert.ToString(valueArrayCustomerDetails[row, 1]);
    sNotice_No = (string)valueArrayCustomerDetails[row, 2];
    dt_notice_date = Convert.ToDateTime(valueArrayCustomerDetails[row, 3]);
    sAgreement_No = Convert.ToString(valueArrayCustomerDetails[row, 4]);
    sBorrower = (string)valueArrayCustomerDetails[row, 5];
}
catch (Exception ex)
{
    MessageBox.Show(ex.ToString() + "\n Error At :- Row-" + row + " Column-"); // here i want variable name at which error occurs
    throw;
}

Answer 1

好吧，如果你想要這些信息，你必須使用多個 try-catch：

try
{
    sSrNo = Convert.ToString(valueArrayCustomerDetails[row, 1]);
}
catch (Exception ex)
{
    MessageBox.Show(ex.ToString() + "\n Error At :- Row-" + row + " 1"); 
    throw;
} 

try
{
    sNotice_No = (string)valueArrayCustomerDetails[row, 2];
}
catch (Exception ex)
{
    MessageBox.Show(ex.ToString() + "\n Error At :- Row-" + row + " 2"); 
    throw;
}

// ...

另一種選擇是創建一個像這樣的輔助方法：

public static class Utils
{
    public static T TryDo<T>(Func<T> returnMethod, Action<Exception> exceptionAction = null, bool throwOnException = true, T fallbackValue = default(T))
    {
        try
        {
            return returnMethod();
        }catch(Exception ex)
        {
            exceptionAction(ex);
            if(throwOnException)
            {
                throw;
            }
        }
        
        return fallbackValue;
    }
}

現在你可以使用這個簡潔易讀的代碼：

sSrNo = Utils.TryDo(() => Convert.ToString(valueArrayCustomerDetails[row, 1]), ex => MessageBox.Show(GetMessage(ex, row, 1)));
sNotice_No = Utils.TryDo(() => Convert.ToString(valueArrayCustomerDetails[row, 2]), ex => MessageBox.Show(GetMessage(ex, row, 2)));
dt_notice_date = Utils.TryDo(() => Convert.ToDateTime(valueArrayCustomerDetails[row, 3]), ex => MessageBox.Show(GetMessage(ex, row, 3)));
sAgreement_No = Utils.TryDo(() => Convert.ToString(valueArrayCustomerDetails[row, 4]), ex => MessageBox.Show(GetMessage(ex, row, 4)));
sBorrower = Utils.TryDo(() => Convert.ToString(valueArrayCustomerDetails[row, 5]), ex => MessageBox.Show(GetMessage(ex, row, 5)));

// local method
string GetMessage(Exception ex, int row, int col) 
    => $"{ex.ToString()} Error At :- Row-{row} Column-{col}";

Answer 2

嘗試使用這個：

它將給出拋出異常的行號，從而獲取變量。

catch(Exception ex)
{
var LineNumber = new StackTrace(ex, true).GetFrame(0).GetFileLineNumber();

MessageBox.Show(ex.StackTrace + "\n Error at :- Row-" + LineNumber);
}

ex.StackTrace 給出了詳細的錯誤信息。

Answer 3

string index="1";
try
{
    sSrNo = Convert.ToString(valueArrayCustomerDetails[row, 1]);
index="2";
sNotice_No = (string)valueArrayCustomerDetails[row, 2];
index="3";
dt_notice_date = 
Convert.ToDateTime(valueArrayCustomerDetails[row, 3]);
index="4";
sAgreement_No = 
Convert.ToString(valueArrayCustomerDetails[row, 4]);
index="5";
sBorrower = (string)valueArrayCustomerDetails[row, 5];
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString() + "\n Error At :- Row-" + row + " 
Column-"+index); // here i want variable name at which error occurs
throw;
}