qt 基础知识2

screenshotLabel = new QLabel;
screenshotLabel->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);//使用QSizePolicy::Expanding  QLabel就会随着窗体的变化而变化
screenshotLabel->setAlignment(Qt::AlignCenter);　　// 对齐
screenshotLabel->setMinimumSize(240, 160);　　// 最小

让qtextedit 不能输入，只读

m_Logw=newQTextEdit();

m_Logw->setReadOnly(true);

让qlinetext 按enter键 就能执行，触发returnPressed() 信号

connect(m_InputArea,SIGNAL(returnPressed()),

this,SLOT(execute()));