QT layout 不显示控件

zylthinking

不知道怎么回事，菜单， 工具栏都可以显示， 就是放在 layout中的 button 不显示， 代码如下:

2 #include "frame.h"
  3 #include <QtGui>
  4
  5 Frame::Frame(){
  6     createActions();
  7     createMenus();
  8     creatToolBars();
  9     createStatusBar();
10
11     createWidgets();
12 }
13
14 Frame::~Frame(){
15     delete newAction;
16     delete saveAction;
17     delete aboutAction;
18
19     delete fileMenu;
20     delete helpMenu;
21
22     delete fileToolBar;
23     delete helpToolBar;
24 }
25
26 void Frame::createActions(){
27     newAction = new QAction(tr("&New"), this);
28     connect(newAction, SIGNAL(triggered()), this, SLOT(newFile()));
29
30     saveAction = new QAction(tr("&Save"), this);
31     connect(saveAction, SIGNAL(triggered()), this, SLOT(saveFile()));
32
33     aboutAction = new QAction(tr("&About"), this);
34     connect(aboutAction, SIGNAL(triggered()), this, SLOT(about()));
35
36     quitAction = new QAction(tr("&Quit"), this);
37     connect(quitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
38 }
39
40 void Frame::createMenus(){
41     fileMenu = menuBar()->addMenu(tr("&File"));
42     fileMenu->addAction(newAction);
43     fileMenu->addAction(saveAction);
44     fileMenu->addSeparator();
45     fileMenu->addAction(quitAction);
46     
47     helpMenu = menuBar()->addMenu(tr("&Help"));
48     helpMenu->addAction(aboutAction);
49 }
50
51 void Frame::creatToolBars(){
52     fileToolBar = addToolBar(tr("&File"));
53     fileToolBar->addAction(newAction);
54     fileToolBar->addAction(saveAction);
55
56     helpToolBar = addToolBar(tr("&Help"));
57     helpToolBar->addAction(aboutAction);
58 }
59
60 void Frame::createWidgets(){
61     QVBoxLayout* layout = new QVBoxLayout;
62
63     QGridLayout* topLayout = new QGridLayout;
64     //QHBoxLayout* botLayout = new QHBoxLayout;
65
66     createTopWidgets(topLayout);
67     //createBotWidgets(botLayout);
68
69     layout->addLayout(topLayout);
70     //layout->addLayout(botLayout);
71     setLayout(layout);
72 }
73
74 void Frame::createTopWidgets(QGridLayout* layout){
75     QPushButton* button1 = new QPushButton("button1");
76     QPushButton* button2 = new QPushButton("button2");
77     QPushButton* button3 = new QPushButton("button3");
78     QPushButton* button4 = new QPushButton("button4");
79     QPushButton* button5 = new QPushButton("button5");
80     QPushButton* button6 = new QPushButton("button6");
81
82     layout->addWidget(button6, 0, 0, 1, 1);
83     layout->addWidget(button4, 0, 1, 1, 1);
84     layout->addWidget(button5, 0, 2, 1, 1);
85     layout->addWidget(button3, 1, 0, 1, 1);
86     layout->addWidget(button1, 1, 1, 1, 1);
87     layout->addWidget(button2, 1, 2, 1, 1);
88 }
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