错误:'类'不命名类型C++
问题描述:
我见过这个问题的很多帖子。无论如何无法解决我的问题。错误:'类'不命名类型C++
我的问题是,我想从我的B类发一声我的A类A级已经有了B类声明(B B),但不能做B级相同(A一)
可以看出,如果A类包括B类,那么如果B类包括A类,则不起作用。 “A不命名类型”
我将显示我的节拍器程序中的代码。
这是testApp.h
#ifndef TESTAPP_H_
#define TESTAPP_H_
#pragma once
#include "ofMain.h"
#include "ofxSimpleGuiToo.h"
#include "ofxSynth.h"
#include "threadedObject.h"
class testApp : public ofBaseApp{
public:
// virtual string getName() { return "testApp"; }
testApp(){
}
ofxSynth synth;
threadedObject TO;
void setup();
void update();
void draw();
int count;
int rate;
int last_time;
void audioOut(float *input, int bufferSize, int nChannels);
ofSoundStream soundstream;
//testApp();
friend void bang();
void keyPressed (int key);
void keyReleased(int key);
void mouseMoved(int x, int y);
void mouseDragged(int x, int y, int button);
void mousePressed(int x, int y, int button);
void mouseReleased(int x, int y, int button);
void windowResized(int w, int h);
void dragEvent(ofDragInfo dragInfo);
void gotMessage(ofMessage msg);
ofEventArgs eventA;
int mainAppsCount;
void bang(){
synth.trigger();
}
private:
int bpm;
int current_bpm;
float current_frequency;
float frequency;
float volume;
};
#endif
#ifndef THREADED_OBJECT_H
#define THREADED_OBJECT_H
#pragma once
#include "ofMain.h"
#include "testApp.h"
这里是threadedObject类!在这里,我只是想送一“砰”地testApp
class threadedObject : public ofThread {
public:
testApp ta; #HERE IS THE FAIL
ofRectangle posRect;
int count;
int count2;
friend void bang();
double bpmToSeconds;
double changedBpm;
double sum;
int counter;
int check;
//--------------------------
threadedObject(){
// testApp hej;
count = 1;
count2=0;
bpmToSeconds=60;
changedBpm=135;
sum = bpmToSeconds/changedBpm;
counter=0;
}
//--------------------------
void start(){
startThread(true, false);
}
//--------------------------
void stop(){
stopThread();
}
//--------------------------
void threadedFunction(){
while(isThreadRunning() != 0){
if(lock()){
count++;
if(count>4) count= 1;
unlock();
counter++;
ofSleepMillis(getBpm() * 1000);
}
}
}
//--------------------------
void bpm(double bpm)
{
changedBpm=bpm;
sum = bpmToSeconds/changedBpm;
}
//--------------------------
double getBpm(){
return sum;
}
//--------------------------
void draw(){
string str = "I am a slowly increasing thread. \nmy current count is: ";
string tick = " TICK!";
string tock = " TOCK!";
posRect.set(150, 150, 0, 0);
if(lock()){
str += ofToString(count);
if(counter%4==0){
str += tock;
}else {
str += tick;
#Here i want to send a bang to testApp like ta.bang();
}
unlock();
}else{
str = "can't lock!\neither an error\nor the thread has stopped";
}
ofDrawBitmapString(str, 350, 156);
}
int getTick()
{
return counter;
}
};
#endif
显示的testApp.cpp藏汉
#include "testApp.h"
static const int bufferSize = 512;
static const int sampleRate = 44100;
//--------------------------------------------------------------
void testApp::setup(){
volume = 0.5f;
gui.addTitle("Master volume");
gui.addSlider("Volume", volume, 0.5f, 1.f);
frequency = current_frequency = 0.1f;
gui.addTitle("Base Frequency");
gui.addSlider("frequency", frequency, 20.f, 2000.f);
bpm=current_bpm;
bpm=135;
gui.addTitle("Metronome");
gui.addSlider("Bpm", bpm, 40.f, 140.f);
mainAppsCount = 0;
TO.start();
gui.show();
synth.setSampleRate(sampleRate);
soundstream.setup(this, 2, 0, sampleRate, bufferSize, 4);
}
//--------------------------------------------------------------
void testApp::update(){
if(current_frequency != frequency)
{
synth.setFrequency(frequency);
current_frequency = frequency;
}
synth.setVolume(volume);
mainAppsCount++;
TO.bpm(bpm);
}
//--------------------------------------------------------------
void testApp::draw(){
ofSetHexColor(0xffffff);
TO.draw();
string str = "I am a the main opengl thread.\nmy current count is: ";
str += ofToString(mainAppsCount);
ofDrawBitmapString(str, 350, 256);
ofSetHexColor(0xff0033);
ofDrawBitmapString("press 's' to stop the thread and 'a' to start it", 250, 360);
gui.draw();
}
//--------------------------------------------------------------
void testApp::keyPressed(int key){
if (key == 'a'){
TO.start();
} else if (key == 's'){
TO.stop();
}
}
void testApp::audioOut(float * output, int bufferSize, int nChannels)
{
synth.audioOut(output, bufferSize, nChannels, 0);
}
//--------------------------------------------------------------
void testApp::mousePressed(int x, int y, int button){
bang(); #The bang is in testApp.h. for just triggering the synth to play!
}
那么,怎样才能用我的一声()方法testApp.h在threadedobject.h ?
答
A.H:
class B; // forward decl
class A {
B*b;
public:
void bang();
void send();
/* ... */
};
B.h:
class A; // forward decl
class B {
A*a;
public:
void bang();
void send();
/* ... */
};
A.cc
#include A.h
#include B.h
void A::bang() { /* ... */ }
void A::send()
{
b->bang();
}
B.cc
#include B.h
#include A.h
void B::bang() { /* ... */ }
void B::send()
{
a->bang();
}
ö当然,你可能只需要一个头文件和一个源文件。
编辑
当然,必须注意的是B::a
和A::b
都指向有效的指针(完全构造)的对象。
阅读[本](http://*.com/questions/16205367/two-template-classes-being-composed-of-a-member-of-each-other)。 – 2013-04-29 10:36:20
是的,我知道我应该使用指针/参考 在这种情况下testApp * ta; 但是我如何使用ta? TA->邦(); ta.bang(); 当我做ta->砰();我得到这个: 错误:在'((threadedObject *)this)成员'bang'的请求 - > threadedObject :: ta',它是非类类型'testApp *'| – Drole 2013-04-29 11:09:45
您应该在'threadedObject'类的定义之前放置前面声明'class testApp;'。使用'ta-> bang();'因为'ta'现在是一个指针。再次注意我在另一个问题中的解释。在那里,在类“A”的定义之前,我已经向前声明了'B',即'class B;'。 – 2013-04-29 11:24:14