摘要： 比较重要的函数。 哪有不重要的函数呢？ 标题就这样起，有合适的名字再改。
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1. int QDialog::exec() [slot]
帮助文档:
int QDialog::exec () [slot]
Shows the dialog as a modal dialog, blocking until the user closes it. The function returns a DialogCode result.
If the dialog is application modal, users cannot interact with any other window in the same application until they close the dialog. If the dialog is window modal, only interaction with the parent window is blocked while the dialog is open. By default, the dialog is application modal.
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2. void QDialog::accepted () [signal]
帮助文档
void QDialog::accepted () [signal]
This signal is emitted when the dialog has been accepted either by the user or by calling accept() or done() with the QDialog::Accepted argument.
Note that this signal is not emitted when hiding the dialog with hide() or setVisible(false). This includes deleting the dialog while it is visible.
This function was introduced in Qt 4.1.
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