[pre]bool MainWindow::maybeSave()[pre]{[/pre][pre] Q_ASSERT(textEdit);[/pre][pre] [/pre][pre] if(!textEdit->document()->isModified())[/pre][pre] return true;[/pre][pre] if(filename.startsWith(QLatin1String(":/")))[/pre][pre] return true;[/pre]
[pre] QMessageBox::StandardButton res = QMessageBox::warning(this,tr("Application"),tr("this file has been changed"[/pre][pre] "do you want to save it"),QMessageBox::Save|QMessageBox::Discard|QMessageBox::Cancel);[/pre][pre] if(QMessageBox::Save == res)[/pre][pre] return save();[/pre][pre] else[/pre][pre] return false;[/pre][pre] return true;[/pre]
[pre]}[/pre][pre]————————————————————————[/pre][pre]textEdit是QTextEdit的一个实例，，实例是类似win的TXT文档编辑器，，[/pre][pre][/pre][pre]textEdit->document()得到文档内容，但是每次运行这行就报错，提示内存不能访问的数据.....[/pre][pre][/pre][pre]查找相关的文档[/pre][pre]
Note: The editor does not take ownership of the document[/pre] unless it is the document's parent object.
The parent object of the provided document remains the owner of the object.
If the current document is a child of the text editor, then it is deleted.
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牛人指点下
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