c# - 从方法返回 boolean 值

我正在程序中保存一个选项，将更改保存到文件中。我正在使用此代码保存并获取MessageBox以显示过程的结果我在“对象引用未设置为对象的实例”这一行上遇到错误。

     SaveFileCheck = StockHandler.SaveChangesToFile();

这是我的代码

    private void Save_Click(object sender, EventArgs e)
    {

        bool SaveFileCheck = false;
        var result = MessageBox.Show("Are you sure you want to Save the changes ?", "My   Application",
      MessageBoxButtons.YesNo, MessageBoxIcon.Asterisk);
        if (result == DialogResult.Yes)
        {

                 SaveFileCheck = StockHandler.SaveChangesToFile();
                 if (SaveFileCheck)
                 {
                     MessageBox.Show("The process was a success");
                 }
                 else
                 {
                     MessageBox.Show("The process failed please make sure that the file is not been       used and try again");
                 }

            //Save the file back


        }
    }
}
}

    public bool SaveChangesToFile()
    {
        try
        {
            if (FileName != null)
            {
                using (StreamWriter Write = new StreamWriter(FileName, false))
                {
                    foreach (Stock s in FileStockList)
                    {
                        Write.Write(s.ToString() + "\r\n");

                    }

                }
            }
            else {
                return false;
            }

        }
        catch(IOException ex)
        {
            return false;
            throw new ArgumentException("something went wrong an error" + ex + "is been cought");

        }
        return true;


    }

最佳答案

StockHandler为空。

如果StockHandler不是static类，则需要创建它的实例，然后才能对其调用方法：

var handler = new StockHandler();
SaveFileCheck = handler.SaveChangesToFile();

或者，如果StockHandler是成员变量：

StockHandler = new // something

关于c# - 从方法返回 boolean 值，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/7773837/