如果文本框为空代码如何实现错误

Question

在实现两个文本框都为空的方法时，我一直有这个问题。每当我执行IsNullOrEmpty或textbox == 0时，我的文本框就会得到豁免。

我能不能用一种更简单的方式来处理这个问题?

public int number 1;
public int number 2;
public int answer 3;
private void Add_Click(object sender, RoutedEventArgs e)
{  
//text box
number1 = int.Parse(TextBox1.Text);
number2 = int.Parse(TextBox2.Text);
//if number1 and number2 are less than 1
if (number1 < 1 || number2 < 1 || number1 > 100 || number2 > 100)
{
MessageBox.Show("INVALID INPUT");
TextBox1.Text = " ";
TextBox2.Text = " ";
}
// if both text boxes are empty 
// send error message
// end if statement
else
{
// operation
answer = number1 + number2;
//
// when clicked
answerText.Text = answer.ToString();
}
}

Answer 1

可以包含一个TryParse。

bool number1b = int.TryParse(TextBox1.Text, out number1)
bool number2b = int.TryParse(TextBox2.Text, out number2);
if (number1b && number2b)
{
if (number1 < 1 || number2 < 1 || number1 > 100 || number2 > 100)
{
MessageBox.Show("Integer inputs can not be outside of 1-100.");
}
else
{
answer = number1 + number2;
answerText.Text = answer.ToString();
}
}
else
{
MessageBox.Show("Inputs could not be converted to an integer.");
}