我有 2 個面板。如果文本框為空，則有一條訊息。我的問題是，假設我進入第二個面板然后回傳并洗掉文本然后再次進入第二個面板，它不顯示訊息。有沒有辦法每次都檢查文本？
private void bttn_Next_Click(object sender, EventArgs e)
{
if (txt_FirstName.Text == " " || txt_LastName.Text == " " ||
txt_Email.Text == " " || txt_Contact.Text == " " ||
txt_HouseNumber.Text == " " || txt_Street.Text == " " ||
txt_Barangay.Text == " " || txt_Municipality.Text == "")
{
MessageBox.Show("Please complete all required fields.", "Message");
}
else
{
panel1.Hide();
panel2.Hide();
panel3.Show();
}
}
uj5u.com熱心網友回復：
檢查空字串的正確方法如下
private void bttn_Next_Click(object sender, EventArgs e)
{
if (string.IsNullOrWhiteSpace(txt_FirstName.Text) || string.IsNullOrWhiteSpace(txt_LastName.Text) ||
string.IsNullOrWhiteSpace(txt_Email.Text) || string.IsNullOrWhiteSpace(txt_Contact.Text) ||
string.IsNullOrWhiteSpace(txt_HouseNumber.Text) || string.IsNullOrWhiteSpace(txt_Street.Text) ||
string.IsNullOrWhiteSpace(txt_Barangay.Text) || string.IsNullOrWhiteSpace(txt_Municipality.Text))
{
MessageBox.Show("Please complete all required fields.", "Message");
}
else
{
panel1.Hide();
panel2.Hide();
panel3.Show();
}
}
轉載請註明出處，本文鏈接：https://www.uj5u.com/qita/487568.html
上一篇：如果另一個作業表列中的文本包含“特定文本”，則Google腳本運行函式
下一篇：scala：如果條件從未評估過