在while循環中處理異常

Question

我想在我的應用程序中記錄一條錯誤消息，以重試調出Web服務，但是我只想在while循環之外一次顯示該錯誤消息，而不是每次重試和失敗時都記錄錯誤，或者我應該做一次環。

int retryCount = x;
int retryWait = y;

int retry = 0;

while (retry <= retryCount)
{
    try
    {
        //get response
    }
    catch (InvalidOperationException invalid)
    {
        message = //display status message 
    }
    catch (Exception exc)
    {
        //display log message 
        //retry again 
        retry++;

    }
    message = "Mamium tries have been exceeded
    Logs.WriteError(message);
    return false;
}

Answer 1

只需重置消息，然后檢查是否有消息，例如：

    while (retry <= retryCount)
    {
        try
        {
            message = null;
            //get response
        }
        catch (InvalidOperationException invalid)
        {
            message = invalid.Message; //display status message 
        }
        catch (Exception exc)
        {
            //display log message 
            //retry again 
            message = exc.Message; //display status message 
            retry++;

        }

        if (!string.IsNullOrEmpty(message))
        {
            message = "Mamium tries have been exceeded"
            Logs.WriteError(message);
            return false;
        }
    }

Answer 2

您可以使用您的retry和retryCount變量作為樣本，並使用finally塊進行增量。

{ // main scope

    int retry = 0, retryCount = 3;
    string message = null;

    while (retry < retryCount)
    {   
        try
        {
            //get response      
        }
        catch (Exception exc) 
        {
            //any error, since you don't need to give another threatment for other erros, just use  Exception

            message = exc.Message;
        }
        finally
        {   
            // increment retry anyway
            retry++;
        }
    }

    if (retry >= retryCount)
    {
        message = "Mamium tries have been exceeded"
        Logs.WriteError(message);
        return false;
    }       

    return true;
}