Question

c# textbox.text为空时的值

private void DcTextBox_TextChanged(object sender, EventArgs e)
{
if (this.cTgroupBox.Text.Trim() == "") //这个判断如何为真
{
this.Menupanel.Visible = false; //1
}
if (this.cTgroupBox.Text.Trim() != "")
{
this.Menupanel.Visible = true; //2 1,2两处设置断点 一直都是进2

}
}
怎么才能进1 或者如何判断textBox中已经没有字符了

Answer 1

if( string.IsNullOrEmpty(this.cTgroupBox.Text) )
{
this.Menupanel.Visible = false;

}
else
{
this.Menupanel.Visible = true;

}

Answer 2

this.cTgroupBox 里面什麼也不写就是为 "" 了

Answer 3

不输入任何内容就满足条件了