Qt4.6 QMessageBox 使用大全

使用方式为
/***消息框的使用 *********************/
//提示框
//QMessageBox::about(this,"about me","helloworld");
// QMessageBox::aboutQt(this,"about me");  //输出关于Qt的详细信息
//警告窗口
//int bs=   QMessageBox::critical(this,"about me","show info",QMessageBox::Ok|QMessageBox::Cancel,QMessageBox::Ok);
//ui.infos->setText(QString(tr("%1")).arg(bs));

//输出信息提示框
//int bs=  QMessageBox::information(this,"about me","information",QMessageBox::Ok|QMessageBox::Cancel|QMessageBox::Discard|QMessageBox::Save,QMessageBox::Ok);
//ui.infos->setText(QString(tr("%1")).arg(bs));

其他使用方式：

QMessageBox msgBox;
 msgBox.setText("The document has been modified.");
 msgBox.setInformativeText("Do you want to save your changes?");
 msgBox.setStandardButtons(QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel);
 msgBox.setDefaultButton(QMessageBox::Save);
 int ret = msgBox.exec();
switch (ret) {
   case QMessageBox::Save:
       // Save was clicked
       break;
   case QMessageBox::Discard:
       // Don't Save was clicked
       break;
   case QMessageBox::Cancel:
       // Cancel was clicked
       break;
   default:
       // should never be reached
       break;
 }

	Question	For asking a question during normal operations.
	Information	For reporting information about normal operations.
	Warning	For reporting non-critical errors.
	Critical	For reporting critical errors.

int ret = QMessageBox::warning(this, tr("My Application"),
                                tr("The document has been modified.\n"
                                   "Do you want to save your changes?"),
                                QMessageBox::Save | QMessageBox::Discard
                                | QMessageBox::Cancel,
                                QMessageBox::Save);



 QMessageBox msgBox;
 QPushButton *connectButton = msgBox.addButton(tr("Connect"), QMessageBox::ActionRole);
 QPushButton *abortButton = msgBox.addButton(QMessageBox::Abort);
 msgBox.exec();
 if (msgBox.clickedButton() == connectButton) {
     // connect
 } else if (msgBox.clickedButton() == abortButton) {
     // abort
 }

Constant	Value	Description
QMessageBox::InvalidRole	-1	The button is invalid.
QMessageBox::AcceptRole	0	Clicking the button causes the dialog to be accepted (e.g. OK).
QMessageBox::RejectRole	1	Clicking the button causes the dialog to be rejected (e.g. Cancel).
QMessageBox::DestructiveRole	2	Clicking the button causes a destructive change (e.g. for Discarding Changes) and closes the dialog.
QMessageBox::ActionRole	3	Clicking the button causes changes to the elements within the dialog.
QMessageBox::HelpRole	4	The button can be clicked to request help.
QMessageBox::YesRole	5	The button is a "Yes"-like button.
QMessageBox::NoRole	6	The button is a "No"-like button.
QMessageBox::ApplyRole	8	The button applies current changes.
QMessageBox::ResetRole	7	The button resets the dialog's fields to default values.

See also StandardButton.

enum QMessageBox::Icon

This enum has the following values:

Constant	Value	Description
QMessageBox::NoIcon	0	the message box does not have any icon.
QMessageBox::Question	4	an icon indicating that the message is asking a question.
QMessageBox::Information	1	an icon indicating that the message is nothing out of the ordinary.
QMessageBox::Warning	2	an icon indicating that the message is a warning, but can be dealt with.
QMessageBox::Critical	3	an icon indicating that the message represents a critical problem.

enum QMessageBox::StandardButton
flags QMessageBox::StandardButtons

These enums describe flags for standard buttons. Each button has a defined ButtonRole.

Constant	Value	Description
QMessageBox::Ok	0x00000400	An "OK" button defined with the AcceptRole.
QMessageBox::Open	0x00002000	A "Open" button defined with the AcceptRole.
QMessageBox::Save	0x00000800	A "Save" button defined with the AcceptRole.
QMessageBox::Cancel	0x00400000	A "Cancel" button defined with the RejectRole.
QMessageBox::Close	0x00200000	A "Close" button defined with the RejectRole.
QMessageBox::Discard	0x00800000	A "Discard" or "Don't Save" button, depending on the platform, defined with theDestructiveRole.
QMessageBox::Apply	0x02000000	An "Apply" button defined with the ApplyRole.
QMessageBox::Reset	0x04000000	A "Reset" button defined with the ResetRole.
QMessageBox::RestoreDefaults	0x08000000	A "Restore Defaults" button defined with the ResetRole.
QMessageBox::Help	0x01000000	A "Help" button defined with the HelpRole.
QMessageBox::SaveAll	0x00001000	A "Save All" button defined with the AcceptRole.
QMessageBox::Yes	0x00004000	A "Yes" button defined with the YesRole.
QMessageBox::YesToAll	0x00008000	A "Yes to All" button defined with the YesRole.
QMessageBox::No	0x00010000	A "No" button defined with the NoRole.
QMessageBox::NoToAll	0x00020000	A "No to All" button defined with the NoRole.
QMessageBox::Abort	0x00040000	An "Abort" button defined with the RejectRole.
QMessageBox::Retry	0x00080000	A "Retry" button defined with the AcceptRole.
QMessageBox::Ignore	0x00100000	An "Ignore" button defined with the AcceptRole.
QMessageBox::NoButton	0x00000000	An invalid button.

The following values are obsolete:

Constant	Value	Description
QMessageBox::YesAll	YesToAll	Use YesToAll instead.
QMessageBox::NoAll	NoToAll	Use NoToAll instead.
QMessageBox::Default	0x00000100	Use the defaultButton argument of information(), warning(), etc. instead, or call setDefaultButton().
QMessageBox::Escape	0x00000200	Call setEscapeButton() instead.
QMessageBox::FlagMask	0x00000300
QMessageBox::ButtonMask	~FlagMask