该窗体具有FormClosing事件，其参数类型为FormClosingEventArgs。

private void Form1_FormClosing( object sender, FormClosingEventArgs e ) { if ( e.CloseReason == CloseReason.UserClosing ) { if ( MessageBox.Show( this, "Really?", "Closing...", MessageBoxButtons.OKCancel, MessageBoxIcon.Question ) == DialogResult.Cancel ) e.Cancel = true; } } 

你可以完全删除’X’吗？

表单的一个属性是“ControlBox”，只是将其设置为false

如果要将返回的字段设置为null，就像在表单中单击“取消”时所做的那样：

 private void Form1_FormClosing( object sender, FormClosingEventArgs e ) { if ( e.CloseReason == CloseReason.UserClosing ) { returnfield = null; this.close(); } } 

对于OnFormClosing ， FormClosingEventArgs.CloseReason是UserClosing要么是’X’按钮，要么是form.Close()方法。 我的解决方案

 //override the OnFormClosing event protected override void OnFormClosing(FormClosingEventArgs e) { if (e.CloseReason == CloseReason.ApplicationExitCall)// the reason that you need base.OnFormClosing(e); else e.Cancel = true; // cancel if the close reason is not the expected one } //create a new method that allows to handle the close reasons public void closeForm(FormClosingEventArgs e) { if (e.CloseReason == CloseReason.UserClosing) this.Close(); else e.Cancel = true; } //if you want to close the form or deny the X button action invoke closeForm method myForm.closeForm(new FormClosingEventArgs(CloseReason.ApplicationExitCall, false)); //the reason that you want ↑ 

在此示例中，关闭（X）按钮不会关闭表单

上述就是C#学习教程：单击C＃表单X按钮分享的全部内容，如果对大家有所用处且需要了解更多关于C#学习教程，希望大家多多关注—计算机技术网(www.ctvol.com)!