ERLANG wx小部件加载png

Question

我尝试构建一个包含 PNG 照片的 GUI。 PNG加载代码在加载到空框架时工作正常，但是在这段代码上我看不到照片。我试图更改 wxBoxSizers 的选项和面板上的位置 {0,0}，但我仍然看不到照片。有帮助吗？

首先，我设置了所有的框架和组件

-module(neuron_wx).
-author("adisolo").
%% API
-export([start/0, handleButtonStart/2]).
-include_lib("wx/include/wx.hrl").

-record(data, {env, file}).

%% Will get the pid of server
%% will send the information on button pressing
start() ->

  %%Frame and components build
  WX = wx:new(),
  Frame = wxFrame:new(wx:null(), 1, "Top Frame"),
  TopTxt = wxStaticText:new(Frame, ?wxID_ANY, "Analog Neuron final Project"), %%?wxID_ANY


  %L Components
  TextConfiguration = wxStaticText:new(Frame, ?wxID_ANY, "Program Configuration"), %%?wxID_ANY
  TextSetNumNeurons = wxStaticText:new(Frame, ?wxID_ANY, "Enter number of Neurons per Layer"), %%?wxID_ANY
  TextCtrlNeurons = wxTextCtrl:new(Frame, ?wxID_ANY,  [{value, "example:4 3 6 7"}]),
  ButtonBuild = wxButton:new(Frame, ?wxID_ANY, [{label, "Build"}]), %{style, ?wxBU_LEFT}
  FilePickerInput = wxFilePickerCtrl:new(Frame, ?wxID_ANY),
  ButtonStart = wxButton:new(Frame, ?wxID_ANY, [{label, "Start"}]),

  %Buttons
  wxButton:connect(ButtonStart, command_button_clicked, [{callback, fun handleButtonStart/2}, {userData, #data{env = wx:get_env(), file=FilePickerInput}}]),

这是我放入面板并使用图片的地方

  %R Components
  TextNet = wxStaticText:new(Frame, ?wxID_ANY, "Net Description"), %%?wxID_ANY

  %% panel for picture
  Panel = wxPanel:new(Frame),
  %% bitmap
  PictureDraw = wxImage:new("Erlang_logo.png"),
  Picture = wxBitmap:new(PictureDraw),
  wxPanel:connect(Panel, paint, [{callback,fun(WxData, _)->panelPictureUpdate(Picture, WxData)end}]),


  %3 Components
  TextOutput = wxStaticText:new(Frame, ?wxID_ANY, "Program Output"), %%?wxID_ANY



  %%Font set
  Font = wxFont:new(20, ?wxFONTFAMILY_ROMAN, ?wxFONTSTYLE_NORMAL, ?wxFONTWEIGHT_NORMAL),
  wxTextCtrl:setFont(TopTxt, Font),
  Font2 = wxFont:new(18, ?wxFONTFAMILY_ROMAN, ?wxFONTSTYLE_NORMAL, ?wxFONTWEIGHT_NORMAL),
  wxTextCtrl:setFont(TextConfiguration, Font2),
  wxTextCtrl:setFont(TextOutput, Font2),
  wxTextCtrl:setFont(TextNet, Font2),

  Font3 = wxFont:new(12, ?wxFONTFAMILY_ROMAN, ?wxFONTSTYLE_NORMAL, ?wxFONTWEIGHT_NORMAL),
  wxTextCtrl:setFont(TextSetNumNeurons, Font3),


  %%Sizer Attachment
  MainSizer = wxBoxSizer:new(?wxVERTICAL),
  MainSizer2 = wxBoxSizer:new(?wxHORIZONTAL),
  MainSizerL = wxBoxSizer:new(?wxVERTICAL),
  MainSizerR = wxBoxSizer:new(?wxVERTICAL),
  MainSizer3 = wxBoxSizer:new(?wxVERTICAL),

  wxSizer:add(MainSizer, TopTxt, [{flag, ?wxALIGN_TOP bor ?wxALIGN_CENTER}, {border, 5}]),
  wxSizer:add(MainSizer, MainSizer2), %,[{flag, ?wxALIGN_CENTER}]),
  wxSizer:add(MainSizer, MainSizer3),
  wxSizer:add(MainSizer2, MainSizerL, [{border, 5}]),%{flag, ?wxALIGN_LEFT},
  wxSizer:add(MainSizer2, MainSizerR, [{border, 5}]),%{flag, ?wxALIGN_RIGHT},

  %% Assign to L
  lists:foreach(fun(X)-> wxSizer:add(MainSizerL, X, [{flag, ?wxALL bor ?wxEXPAND}, {border, 8}]) end,
    [TextConfiguration, TextSetNumNeurons, TextCtrlNeurons, ButtonBuild, FilePickerInput, ButtonStart]),
  %wxSizer:add(MainSizerL, TextConfiguration, [{flag, ?wxALL bor ?wxEXPAND}, {border, 5}]),
  %wxSizer:add(MainSizerL, TextSetNumNeurons, [{flag, ?wxALL bor ?wxEXPAND}, {border, 5}]),
  %wxSizer:add(MainSizerL, TextCtrlL, [{flag, ?wxALL bor ?wxEXPAND}, {border, 5}]),

  %% Assign to R
  wxSizer:add(MainSizerR, TextNet, [{flag, ?wxALL bor ?wxALIGN_CENTRE }, {border, 8}]),
  wxSizer:add(MainSizerR, Panel, [{flag, ?wxEXPAND}]),%, {proportion, 1}, {border, 8}]),

  %% Assign to 3
  wxSizer:add(MainSizer3, TextOutput, [{flag, ?wxALL bor ?wxALIGN_CENTRE }, {border, 8}]),


  wxWindow:setSizer(Frame, MainSizer),
  %%Show Frame
  wxFrame:show(Frame).

handleButtonStart(WxData,_)->
  %Get the userdata
  Data=WxData#wx.userData,
  wx:set_env(Data#data.env),
  FilePicker = Data#data.file,
  %Use the info
  Frame = wxFrame:new(wx:null(), ?wxID_ANY, "Print"),
  Text=io_lib:format("The file is: ~p~n", [wxFilePickerCtrl:getPath(FilePicker)]),
  wxStaticText:new(Frame, ?wxID_ANY, Text),
  wxFrame:show(Frame).

这是将图片绘制到面板（面板的回调'paint'）我认为这不是我的代码中的问题，因为它确实适用于我尝试过的空框架。

% upload the picture to the panel
  panelPictureUpdate(Picture, #wx{obj =Panel} ) ->
  %% display picture
  DC = wxPaintDC:new(Panel),
  wxDC:drawBitmap(DC, Picture, {0,0}),
  wxPaintDC:destroy(DC),
  ok.

Answer 1

这里的代码太多了，读起来不太舒服，尤其是对于不太了解 Erlang 的人来说，但问题是图片加载不正确，或者面板大小不正确。

要检查前者，您应该验证 image/bitmap 是否有效（使用其 IsOk()）。要检查后者，您需要检查面板是否有足够的 space 来扩展到不仅在其直接父级 sizer 中，而且这个 sizer 本身也被正确定位和调整大小。

最后，请注意，无论如何您都不需要自己绘制图片，您可以使用 wxStaticBitmap 代替。

Answer 2

问题是图片没有正确缩放。我用的是面板的烤漆手柄：

wxPanel:connect(Panel, paint, [{callback,fun(WxData, _)->panelPictureUpdate({Frame,PictureDraw}, WxData)end}])

每次调整 window 大小时重新绘制图片。

{Width, Height} = wxPanel:getSize(Panel),
  PictureDrawScaled = wxImage:scale(PictureDraw, Width, Height),
  %% display picture
  Picture = wxBitmap:new(PictureDrawScaled),
  DC = wxPaintDC:new(Panel),
  wxDC:drawBitmap(DC, Picture, {0,0}),
  wxPaintDC:destroy(DC)

这样图片就缩放到面板大小了。

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