private void button1_Click(object sender, EventArgs e)
{
int num1, num2;
double result;
try
{
if (textBox1.Text == null || textBox2.Text == null)
MessageBox.Show("输入不完整!");
else
{
num1 = Convert.ToInt32(textBox1.Text);
num2 = Convert.ToInt32(textBox2.Text);
result = checked(num1 + num2);
textBox3.Text = Convert.ToString(result);
}
}
catch (OverflowException)
{
textBox3.Text = "加法溢出!";
}
}
我这样做还是不行,该如何修改代码?
{
int num1, num2;
double result;
try
{
if (textBox1.Text == null || textBox2.Text == null)
MessageBox.Show("输入不完整!");
else
{
num1 = Convert.ToInt32(textBox1.Text);
num2 = Convert.ToInt32(textBox2.Text);
result = checked(num1 + num2);
textBox3.Text = Convert.ToString(result);
}
}
catch (OverflowException)
{
textBox3.Text = "加法溢出!";
}
}
我这样做还是不行,该如何修改代码?
{
MessageBox.Show("数据出错,请重新读取数据信息!", "错误", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
int.TryParse(textBox1.Text, out num1);
int.TryParse(textBox2.Text, out num2);
如果无法转化,则默认为0
另:如果要判断没有输入,必须加入不等于空
if (textBox1.Text == null ¦ ¦ textBox2.Text == null¦ ¦ textBox1.Text == String.Empty || textBox2.Text == String.Empty )
所以应该改为:
if (String.IsNullOrEmpty(textBox1.Text) || String.IsNullOrEmpty(textBox2.Text))
{
MessageBox.Show( "输入不完整! ");
return;
}