C# 必须在控制离开当前方法之前分配 out 参数
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The out parameter must be assigned to before control leaves the current method
提问by Dana Yeger
private void getDetails(out IPAddress ipAddress, out int port)
{
IPAddress Ip;
int Port;
try
{
Ip = IPAddress.Parse(textboxIp.Text);
Port = int.Parse(textboxPort.Text);
}
catch (Exception ex)
{
IPAddress Ip null;
int Port = -1;
MessageBox.Show(ex.Message);
}
}
Why i got this compiler error ? my parameters assigned to value in both cases
为什么我得到这个编译器错误？我的参数在两种情况下都分配给 value
采纳答案by matt
You're not assigning any values to the parameters passed into the method - ipAddressand port. Instead of declaring new Ipand Portvariables, just assign the values to the parameters you've passed in:
您没有为传递给方法的参数分配任何值 -ipAddress和port. 无需声明 newIp和Port变量，只需将值分配给您传入的参数：
private void getDetails(out IPAddress ipAddress, out int port)
{
try
{
ipAddress = IPAddress.Parse(textboxIp.Text);
port = int.Parse(textboxPort.Text);
}
catch (Exception ex)
{
ipAddress = null;
port = -1;
MessageBox.Show(ex.Message);
}
}
EDIT:For other developers, if using "out", you must allow the variable the ability to be set at all points in the function - including "if" statements, and the "catch", like here, just like it was being returned, or it will give the error this guy got.
编辑：对于其他开发人员，如果使用“out”，则必须允许在函数的所有点设置变量的能力 - 包括“if”语句和“catch”，就像这里一样，就像它被返回一样，否则它会给出这个家伙得到的错误。
回答by meilke
You are not assigning values to both of the outvariables. You are justassigning values to the ones you created inside the method.
您没有为这两个out变量赋值。您只是将值分配给您在方法中创建的值。
回答by Mark Sherretta
No, you have created another variable - int Port, that is not the same as out int port. You are not assigning a value to the actual out parameter. Same goes for the ipAddressout parameter.
不，您创建了另一个变量 - int Port，它与out int port. 您没有为实际的输出参数分配值。这同样适用于ipAddress输出参数。
回答by Dan Puzey
Quite obviously, you don't assign any value to your outparameters ipAddressand portat any point in the method.
很显然，你不分配给您的任何值out的参数ipAddress，并port在方法中的任一点。
