搞了一下午，看了些资料，终于弄好了matlab GUI中的回调函数。

效果图见底部~

umtitled3.m:

function varargout = untitled3(varargin)

% UNTITLED3 M-file for untitled3.fig

% UNTITLED3, by itself, creates a new UNTITLED3 or raises the existing

% singleton*.

%

% H = UNTITLED3 returns the handle to a new UNTITLED3 or the handle to

% the existing singleton*.

%

% UNTITLED3('CALLBACK',hObject,eventData,handles,...) calls the local

% function named CALLBACK in UNTITLED3.M with the given input arguments.

%

% UNTITLED3('Property','Value',...) creates a new UNTITLED3 or raises the

% existing singleton*. Starting from the left, property value pairs are

% applied to the GUI before untitled3_OpeningFunction gets called. An

% unrecognized property name or invalid value makes property application

% stop. All inputs are passed to untitled3_OpeningFcn via varargin.

%

% *See GUI Options on GUIDE's Tools menu. Choose "GUI allows only one

% instance to run (singleton)".

%

% See also: GUIDE, GUIDATA, GUIHANDLES

% Copyright 2002-2003 The MathWorks, Inc.

% Edit the above text to modify the response to help untitled3

% Last Modified by GUIDE v2.5 18-Mar-2012 16:58:53

% Begin initialization code - DO NOT EDIT

gui_Singleton = 1;

gui_State = struct('gui_Name', mfilename, ...

'gui_Singleton', gui_Singleton, ...

'gui_OpeningFcn', @untitled3_OpeningFcn, ...

'gui_OutputFcn', @untitled3_OutputFcn, ...

'gui_LayoutFcn', [] , ...

'gui_Callback', []);

if nargin && ischar(varargin{1})

gui_State.gui_Callback = str2func(varargin{1});

end

if nargout

[varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});

else

gui_mainfcn(gui_State, varargin{:});

end

% End initialization code - DO NOT EDIT

% --- Executes just before untitled3 is made visible.

function untitled3_OpeningFcn(hObject, eventdata, handles, varargin)

% This function has no output args, see OutputFcn.

% hObject handle to figure

% eventdata reserved - to be defined in a future version of MATLAB

% handles structure with handles and user data (see GUIDATA)

% varargin command line arguments to untitled3 (see VARARGIN)

% Choose default command line output for untitled3

handles.output = hObject;

% Update handles structure

guidata(hObject, handles);

% UIWAIT makes untitled3 wait for user response (see UIRESUME)

% uiwait(handles.figure1);

% --- Outputs from this function are returned to the command line.

function varargout = untitled3_OutputFcn(hObject, eventdata, handles)

% varargout cell array for returning output args (see VARARGOUT);

% hObject handle to figure

% eventdata reserved - to be defined in a future version of MATLAB

% handles structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure

varargout{1} = handles.output;

% --- Executes on button press in openfile.

function openfile_Callback(hObject, eventdata, handles)%打开文件

global filep

filep=OnFileOpen();

% hObject handle to openfile (see GCBO)

% eventdata reserved - to be defined in a future version of MATLAB

% handles structure with handles and user data (see GUIDATA)

% --- Executes on button press in pushbutton2.

function pushbutton2_Callback(hObject, eventdata, handles)%求取sift特征

global filep

global im1

global des1

global loc1

[im1,des1,loc1] = sift(filep);

showkeys(im1,loc1);

% hObject handle to pushbutton2 (see GCBO)

% eventdata reserved - to be defined in a future version of MATLAB

% handles structure with handles and user data (see GUIDATA)

% --- Executes on button press in pushbutton3.

function pushbutton3_Callback(hObject, eventdata, handles)%写入txt文件

global im1

global des1

global loc1

fid=fopen('matrix.txt','w');

fprintf(fid,'%f',des1);%sift特征

fclose(fid);

% hObject handle to pushbutton3 (see GCBO)

% eventdata reserved - to be defined in a future version of MATLAB

% handles structure with handles and user data (see GUIDATA)

图片贴上：

design view:

result view:

property inspector: