c# Textbox textresult不会显示

本文关键字：显示 textresult Textbox | 更新日期: 2023-09-27 18:06:58

这是用于检查第一个数字是否大于第二个数字的代码，但它没有像预期的那样工作。谁能告诉我原因并纠正我?

if (txtFirst.Text == "") 
{ 
    txtFirst.Text = "0"; 
    if (txtSecond.Text == "") 
    { 
        txtSecond.Text = "0"; 
        int first = Convert.ToInt32(txtFirst.Text); 
        int second = Convert.ToInt32(txtSecond.Text); 
        if (first < second) 
        {
            txtResult.Text = "TRUE"; 
        } 
        else 
        { 
            txtResult.Text = "FALSE"; 
        } 
    } 
}

只有当两个文本框都为空("")时，您的场景才有效。因此，如果您喜欢以下内容，将会更好:

if (txtFirst.Text == "") {txtFirst.Text = "0";}
if (txtSecond.Text == ""){txtSecond.Text = "0";}
// it is good to check for null in this scenario since
// Convert.ToInt32() is not capable of handling null
int first = Convert.ToInt32(txtFirst.Text); 
int second = Convert.ToInt32(txtSecond.Text);
if (first < second){txtResult.Text = "TRUE";}
else{txtResult.Text = "FALSE";}