Question

我使用official installation guide安装了Qt for Embedded Linux（Qt 4.8.5）。但是，当我在QtCreator 3.0.1中运行任何已安装的示例时，我收到以下错误：

QWSSocket::connectToLocalFile could not connect:: Connection refused
No Qt for Embedded Linux server appears to be running.
If you want to run this program as a server,
add the "-qws" command-line option.

如果我使用-qws选项运行，我会得到：

QScreenLinuxFb::connect: Permission denied Error opening framebuffer
/dev/fb0 The program has unexpectedly finished.

从Google搜索结果中，我可以看到它与权限设置有关，可能与帧缓冲设备（/ dev / fb0）有关。以下是我的ubuntu 12.04 LTS系统上ls -al /dev/fb0的输出：

$ ls -al /dev/fb0
crw-rw---- 1 root video 29, 0 Apr 21 22:43 /dev/fb0

我已将当前登录的用户添加到video所属的/dev/fb0组。我仍然收到permission denied错误。

如果我使用/examples/qws/framebuffer运行sudo示例，我会得到以下输出：

The framebuffer device was opened successfully.

Fixed screen info:
    id:          inteldrmfb
    smem_start:  0xc0073000
    smem_len:    5763072
    type:        0
    type_aux:    0
    visual:      2
    xpanstep:    1
    ypanstep:    1
    ywrapstep:   0
    line_length: 6400
    mmio_start:  0x0
    mmio_len:    0
    accel:       0

The framebuffer device was mapped to memory successfully.

Was in graphics mode already. Skipping
Variable screen info:
    xres:           1600
    yres:           900
    xres_virtual:   1600
    yres_virtual:   900
    yoffset:        0
    xoffset:        0
    bits_per_pixel: 32
    grayscale: 0
    red:    offset: 16, length:  8, msb_right:  0
    green:  offset:  8, length:  8, msb_right:  0
    blue:   offset:  0, length:  8, msb_right:  0
    transp: offset:  0, length:  0, msb_right:  0
    nonstd:       0
    activate:     0
    height:       -1
    width:        -1
    accel_flags:  0x1
    pixclock:     0
    left_margin:  0
    right_margin: 0
    upper_margin: 0
    lower_margin: 0
    hsync_len:    0
    vsync_len:    0
    sync:         0
    vmode:        0

Frame Buffer Performance test...
        Average:   916 usecs
        Bandwidth: 6000.102 MByte/Sec
        Max. FPS:  1091.703 fps

Will draw 3 rectangles on the screen,
they should be colored red, green and blue (in that order).
  Done.

但是，我在屏幕上看不到3个矩形。

有人可以帮助概述如何在Ubuntu桌面环境中运行这些Qt for Embedded Linux（Qt 4.8.5）示例吗？

Answer 1

我也只使用12.04系统但使用Qt 4.6.1。我遇到了和你一样的问题，发现当我从控制台（Ctrl + Alt + F1）终端运行-qws时，可以看到GUI。当从GUI终端或Qt Creator运行时，虽然显示了窗口，但操作系统的GUI（X11）在屏幕刷新期间用其内容覆盖屏幕。

如果您希望能够从Qt Creator或GUI OS运行Qt GUI应用程序， qvfb 需要在后台运行。此链接会提供以下信息：http://qt-project.org/doc/qt-4.8/qvfb.html

希望这有帮助！

运行Qt for Embedded Linux 4.8.5示例

1 个答案: