c# - 有人可以用英语向我解释这段 MSDN 代码吗？

Question

这是并发相关的。因此 SubmitChanges() 失败，并抛出 ChangeConflictException。对于 db.ChangeConflicts 中的每个 ObjectChangeConflict，其 Resolve 设置为 RefreshMode.OverwriteCurrentValues？这是什么意思？

http://msdn.microsoft.com/en-us/library/bb399354.aspx

Northwnd db = new Northwnd("...");
try
{
    db.SubmitChanges(ConflictMode.ContinueOnConflict);
}

catch (ChangeConflictException e)
{
    Console.WriteLine(e.Message);
    foreach (ObjectChangeConflict occ in db.ChangeConflicts)
    {
        // All database values overwrite current values.
        occ.Resolve(RefreshMode.OverwriteCurrentValues);
    }
}

Answer 1

我在代码中添加了一些注释，看看是否有帮助:

Northwnd db = new Northwnd("...");
try
{
    // here we attempt to submit changes for the database
    // The ContinueOnConflict specifies that all updates to the 
    // database should be tried, and that concurrency conflicts
    // should be accumulated and returned at the end of the process.
    db.SubmitChanges(ConflictMode.ContinueOnConflict);
}

catch (ChangeConflictException e)
{
    // we got a change conflict, so we need to process it
    Console.WriteLine(e.Message);

    // There may be many change conflicts (if multiple DB tables were
    // affected, for example), so we need to loop over each
    // conflict and resolve it. 
    foreach (ObjectChangeConflict occ in db.ChangeConflicts)
    {
        // To resolve each conflict, we call
        // ObjectChangeConflict.Resolve, and we pass in OverWriteCurrentValues
        // so that the current values will be overwritten with the values
        // from the database
        occ.Resolve(RefreshMode.OverwriteCurrentValues);
    }
}