我是一个新手,刚开始学什么都不是很明白呢希望各位高手能够指导一下新手问题可能很简单,但是希望能说明白点程序如下,总是报错,但是我感觉没有错误:private void button2_Click(object sender, EventArgs e)
{
IPAddress[] ip=null;
try
{
ip = Dns.GetHostAddresses(this.textBox1.Text);
}
catch (Exception ey)
{
MessageBox.Show(ey.Message);
this.textBox1.Focus();
this.textBox1.SelectAll();
return;
}
this.textBox2.Text = ip[0].ToString();
}
public string Nettest()
{
string sNetId;
for (int i = 1; i <= 256; i++)
{
for (int j = 1; j <= 256; j++)
sNetId = sNetId + i * j + "";
sNetId += "\n";
}
return sNetId;
}
{
IPAddress[] ip=null;
try
{
ip = Dns.GetHostAddresses(this.textBox1.Text);
}
catch (Exception ey)
{
MessageBox.Show(ey.Message);
this.textBox1.Focus();
this.textBox1.SelectAll();
return;
}
this.textBox2.Text = ip[0].ToString();
}
public string Nettest()
{
string sNetId;
for (int i = 1; i <= 256; i++)
{
for (int j = 1; j <= 256; j++)
sNetId = sNetId + i * j + "";
sNetId += "\n";
}
return sNetId;
}
string sNetId;
for (int i = 1; i <= 256; i++)
{
for (int j = 1; j <= 256; j++)
sNetId = sNetId + i * j + "";
sNetId += "\n";
}
你的sNetId是string类型的蛾可以sNetId += "\n";这样吗?
for (int i = 1; i <= 256; i++)
{
for (int j = 1; j <= 256; j++)
sNetId = sNetId + i * j + "";
sNetId += "\n";
}
改为
string sNetId="";
for (int i = 1; i <= 256; i++)
{
for (int j = 1; j <= 256; j++)
sNetId = sNetId + i * j + "";
sNetId += "\n";
}
需要先赋值,另外这个循环好大啊...
你需要给sNetId 赋个初始值啊,否则会报错的,因为你是在没赋值的情况下使用了变量加个String sNetId ="";就可以了建议你先看看基础的c#书籍。
string类型的变量在使用前要先赋值的