等待返回处理后的结果
int function(const int &a)
{
qDebug() << __LINE__ << __FUNCTION__ << __FILE__<<QThread::currentThreadId();
return a*100;
}
QList<int> list{
0,1,2,3};
auto f = QtConcurrent::blockingMapped(list,function);
for (auto& v:f) {
qDebug() << __LINE__ << __FUNCTION__ << __FILE__<<v;
}
返回处理后的结果
QList<int> list{
0,1,2,3};
auto f = QtConcurrent::mapped(list,function);
f.waitForFinished();
for (auto& a: f.results()) {
qDebug() << __LINE__ << __FUNCTION__ << __FILE__<<a;
}
直接修改原队列
void function(int &a)
{
qDebug() << __LINE__ << __FUNCTION__ << __FILE__<<QThread::currentThreadId();
a = a*100;
}
QList<int> list{
0,1,2,3};
auto f = QtConcurrent::map(list,function);
f.waitForFinished();
for (auto& a: list) {
qDebug() << __LINE__ << __FUNCTION__ << __FILE__<<a;
}
将结果继续传递给新函数，并在新函数里再处理成一个单值
新函数必须是“V function(T &result，const U &intermediate)”的形式
int function(const int &a)
{
return a*100;
}
void reduce(int& result,const int& in)
{
result += in ;
}
void Widget::on_pushButton_clicked()
{
QList<int> list{
0,1,2,3};
auto f = QtConcurrent::mappedReduced(list,function,reduce);
f.waitForFinished();
qDebug() << __LINE__ << __FUNCTION__ << __FILE__<<f.result();
}
可以使用成员函数
QStringList lst;
lst<<"123"<<"456"<<"789";
auto f1 = QtConcurrent::blockingMappedReduced(lst,&QString::length,strLength);
qDebug() << __LINE__ << __FUNCTION__ << __FILE__<<f1;
输出
9
auto f2 = QtConcurrent::blockingMappedReduced(lst,&QString::length,&QList<int>::push_back);
输出
(3, 3, 3)
支持函数对象
struct strExpand
{
strExpand(int a):m_a{
a}{
}
typedef QString result_type;//
QString operator()(const QString& str)
{
return str + QString::number(m_a);
}
int m_a{
0};
};
QStringList lst;
lst<<"123"<<"456"<<"7899";
auto f3 = QtConcurrent::mapped(lst,strExpand{
10086});
f.waitForFinished();
qDebug() << __LINE__ << __FUNCTION__ << __FILE__<<f3.results();
bind
int fun(int b,const int& a)
{
return a+1+b;
}
QList<int> list{
0,1,2,3};
auto bFun = std::bind(&fun,100,std::placeholders::_1);
auto f = QtConcurrent::mappedReduced(list,bFun,reduce);
f.waitForFinished();
qDebug() << __LINE__ << __FUNCTION__ << __FILE__<<f.result();
过滤
bool aselect(const int& value)
{
return value%2;
}
auto f11 = QtConcurrent::filtered(list,aselect);
f11.waitForFinished();
run
QtConcurrent::run([]{
qDebug() << __LINE__ << __FUNCTION__ << __FILE__<<QThread::currentThreadId();
});
QFuture<bool> f = QtConcurrent::run(this,&Widget::threadTest,1024);
QFutureWatcher 观察并发结束
m_watcher.setFuture(f);
qDebug() << __LINE__ << __FUNCTION__ << __FILE__;
connect(&m_watcher,&QFutureWatcherBase::finished,this,[&]{
qDebug() << __LINE__ << __FUNCTION__ << __FILE__<<m_watcher.result();
});
