int Convert.Tolnt32(string value) (+ 18過載) 將數字的指定字串表示形式轉換為等效的32位有符號整數。 異常: ## 標題System.FormatExceptionSystem.OverflowException 求解答

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms;

namespace PFD { public partial class 股票 : Form { private Stock myStock; Random r; private EventHandler myStock_OnStockFall; public 股票() { InitializeComponent(); int price= Convert.ToInt32(txtStartPrice.Text);//編譯說我此處錯誤 myStock = new Stock(price); r = new Random(); } class StockEventArgs : EventArgs { int stockPrice; public StockEventArgs(int stockPrice) { this.stockPrice = stockPrice; } public int StockPrice { get { return StockPrice; } } } class Stock { public event EventHandler OnStockChange; public event EventHandler OnStockRise; public event EventHandler OnStockFall; private int stockPrice; public Stock(int price) { stockPrice = price; } //當股票 價格改變 觸發事件； public int Price { set { decimal oldPrice = stockPrice; stockPrice = value;

                if (OnStockChange != null && (oldPrice != value))
                {
                    OnStockChange(this, new StockEventArgs(stockPrice));
                }
                if (OnStockFall != null && (oldPrice > value))
                {
                    OnStockChange(this, new StockEventArgs(stockPrice));
                }
                else if (OnStockRise != null && (oldPrice < value))
                {
                    OnStockChange(this, new StockEventArgs(stockPrice));
                }
            }
            get
            {
                return stockPrice;
            }
        }
    }

    private void btnOpened_Click(object sender, EventArgs e)
    {
        myStock.OnStockChange += new EventHandler<StockEventArgs>(Change);
        timer1.Enabled = true;
    }

    private void btnBuying_Click(object sender, EventArgs e)
    {
        myStock.OnStockFall += new EventHandler<StockEventArgs>(Fall);
    }

    private void btnSelling_Click(object sender, EventArgs e)
    {
        myStock.OnStockRise += new EventHandler<StockEventArgs>(Rise);
    }
    void Change(object sender, StockEventArgs e)
    {
        this.txtCurPrice.Text  = myStock.Price.ToString();
        rtbMessages.AppendText("\n當前股份：" + myStock.Price);
    }
    void Fall(object sender, StockEventArgs e)
    {
        int buy = Convert.ToInt32(txtBuy.Text);
        if (myStock.Price < buy)
        {
            rtbMessages.Text += "\n+買人，賣入價：" + myStock.Price;
            myStock.OnStockFall -= new EventHandler<StockEventArgs>(Fall);
            txtBuy.Text = "";
        }
    void Rise(object sender, StockEventArgs e)
    {
        int sell = Convert.ToInt32(txtSell.Text);
        if (myStock.Price > sell)
        {
            rtbMessages.Text += "\n-買出，賣出價：" + myStock.Price;
            myStock.OnStockRise -= new EventHandler<StockEventArgs>(Rise);
            txtSell.Text = "";
        }
    }

    private void timer1_Tick(object sender, EventArgs e)
    {
        int nowPrice;
    
if (txtCurPrice .Text  == "") nowPrice = Convert.ToInt32(txtStartPrice .Text );
        else nowPrice = Convert.ToInt32(txtCurPrice .Text );
        int change = r.Next(-3, 4);
        myStock.Price = nowPrice + change;
    }
}
 

} } void Rise(object sender, StockEventArgs e) { int sell = Convert.ToInt32(txtSell.Text); if (myStock.Price > sell) { rtbMessages.Text += “\n-買出，賣出價：” + myStock.Price; myStock.OnStockRise -= new EventHandler(Rise); txtSell.Text = “”; } }

    private void timer1_Tick(object sender, EventArgs e)
    {
        int nowPrice;
    
if (txtCurPrice .Text  == "") nowPrice = Convert.ToInt32(txtStartPrice .Text );
        else nowPrice = Convert.ToInt32(txtCurPrice .Text );
        int change = r.Next(-3, 4);
        myStock.Price = nowPrice + change;
    }
}

}