我做了这个声明来检查 TextBox 是否为空,但是 MessageBox 总是出现 TextBox 是否为空。
private void NextButton_Click(object sender, EventArgs e)
{
decimal MarkPoints, x, y;
x = HoursNumericUpDown.Value;
y = MarkNumericUpDown.Value;
MarkPoints = x * y;
//decimal MarkPoints = (decimal)HoursNumericUpDown.Value * (decimal)HoursNumericUpDown.Value;
DataGridViewRow dgvRow = new DataGridViewRow();
DataGridViewTextBoxCell dgvCell = new DataGridViewTextBoxCell();
dgvCell = new DataGridViewTextBoxCell();
dgvCell.Value = MaterialTextBox.Text;
dgvRow.Cells.Add(dgvCell);
dgvCell = new DataGridViewTextBoxCell();
dgvCell.Value = HoursNumericUpDown.Value;
dgvRow.Cells.Add(dgvCell);
dgvCell = new DataGridViewTextBoxCell();
dgvCell.Value = MarkNumericUpDown.Value;
dgvRow.Cells.Add(dgvCell);
dgvCell = new DataGridViewTextBoxCell();
dgvCell.Value = MarkPoints;
dgvRow.Cells.Add(dgvCell);
dataGridView1.Rows.Add(dgvRow);
MaterialTextBox.Clear();
HoursNumericUpDown.Value = HoursNumericUpDown.Minimum;
MarkNumericUpDown.Value = MarkNumericUpDown.Minimum;
if (String.IsNullOrEmpty(MaterialTextBox.Text))
{
MessageBox.Show("Enter Material Name Please.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Warning);
//dataGridView1.Rows.Clear();
}
else
{
/*if (MarkNumericUpDown.Value < 50)
{
int index = dataGridView1.Rows.Add();
dataGridView1.Rows[1].Cells[4].Value = "F";
}
else if (MarkNumericUpDown.Value > 50 && MarkNumericUpDown.Value <= 64)
{
dataGridView1.Rows[index].Cells[4].Value = "F";
}*/
最佳答案
试试这个条件:
if (string.IsNullOrWhiteSpace(MaterialTextBox.Text)) {
// Message box
}
这将处理一些只包含空白字符的字符串,您将不必处理有时可能很棘手的字符串相等性
关于c# - 检查TextBox是否为空并返回MessageBox?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/6156458/