MATLAB GUI：移动绘制点时更新文本框

Question

我有一个 GUI，用户可以在其中单击一个按钮来放置一个点 (drawpoint)。放置该点后，将计算它与之前选择的静态点之间的欧几里得距离。

我希望能够移动按钮创建的点；这样，在移动点后重新计算欧几里德距离并吐入文本框。

我尝试使用 addlistener（在 GUI_OpeningFcn 位置）创建点；但是，我不知道该怎么做，因为在创建按钮之前句柄不存在。

因此问题是：如何动态执行计算并在移动点时吐出值？下面是按钮的代码（它做我想要的）。但是移动点后如何重新计算呢？

也许，这可以使用 WindowbuttonDownFcn 来解决吗？同样，只是不确定如何将其合并到 GUI 中。

% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

h = findobj('Name', 'N');
Ndata = guidata(h);

axes(Ndata.axes1);

mypoint = drawpoint;

handles.distx = mypoint.Position(1);
handles.disty = mypoint.Position(2);

xp = Ndata.xpix;
yp = Ndata.ypix;
handles.poix = abs(double(handles.distx) - double(Ndata.ISOx))/str2double(xp.String);
handles.poiy = abs(double(handles.disty) - double(Ndata.ISOy))/str2double(yp.String);

handles.poi = sqrt(handles.poix^2 + handles.poiy^2)+1.3;

set(handles.edit1, 'Value', handles.poi);
set(handles.edit1, 'String', num2str(handles.poi));

% Update handles structure
guidata(hObject, handles);

Answer 1

您可以在创建点后添加事件监听器。

创建点：
```
mypoint = drawpoint;
```

仅在不存在时添加事件侦听器（将其添加到 handles）：

%Add event listenr only if not exist
if ~isfield(handles, 'el')
    handles.el = addlistener(mypoint, 'ROIMoved', @mypointmoved_Callback);
end

在回调函数中更新编辑框：

function mypointmoved_Callback(src, eventData)
handles = guidata(src.Parent); %Get the handles using the parent of the point (the axes).
handles.distx = src.Position(1);
handles.disty = src.Position(2);
set(handles.edit1, 'String', num2str(handles.distx)); %Simplified version of your code.
drawnow

这是代码的简化版本（我把你的一些代码放在评论中）：

% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)
%h = findobj('Name', 'N');
%Ndata = guidata(h);

%axes(Ndata.axes1);
axes(handles.axes1);

mypoint = drawpoint;

%Add event listenr only if not exist
if ~isfield(handles, 'el')
    handles.el = addlistener(mypoint, 'ROIMoved', @mypointmoved_Callback);
end

handles.distx = mypoint.Position(1);
handles.disty = mypoint.Position(2);

% xp = Ndata.xpix;
% yp = Ndata.ypix;
% handles.poix = abs(double(handles.distx) - double(Ndata.ISOx))/str2double(xp.String);
% handles.poiy = abs(double(handles.disty) - double(Ndata.ISOy))/str2double(yp.String);

% handles.poi = sqrt(handles.poix^2 + handles.poiy^2)+1.3;

% set(handles.edit1, 'Value', handles.poi);
%set(handles.edit1, 'String', num2str(handles.poi));
set(handles.edit1, 'String', num2str(handles.distx));

% Update handles structure
guidata(hObject, handles);


function mypointmoved_Callback(src, eventData)
handles = guidata(src.Parent); %Get the handles using the parent of the point (the axes).
handles.distx = src.Position(1);
handles.disty = src.Position(2);
set(handles.edit1, 'String', num2str(handles.distx));
drawnow

MATLAB GUI：移动绘制点时更新文本框

MATLAB GUI: Update textbox when moving drawpoint

matlab

matlab-guide