从C++ Windows存储应用程序中使用SQLite WINRT 我试图从Windows商店C++应用程序中使用。我想在这个包中专门使用Windows运行时包装，而不是。我试图查看codeplex页面上给出的C示例： C代码 但是我无法计算出那个代码的C++等价。这就是我到目前为止所做的： C++代码

我不太清楚如何使用C中的while循环模拟迭代行为。有指针吗？

不确定这是否是最简单的方法，但一种方法是将循环转换为递归调用。例如，类似这样的事情：

task<void> stepInfoRecursive(std::function<void()> actionToExecute,SQLiteWinRT::Statement^ stmt)
{
    return task<bool>(stmt->StepAsync()).then([actionToExecute,stmt](bool ret){
                        actionToExecute();

                        if (ret){
                             return stepInfoRecursive(actionToExecute,stmt);
                        }
                        return create_task([]{});

                    });
}

auto installLoc = Windows::ApplicationModel::Package::Current->InstalledLocation;

task<Windows::Storage::StorageFile^>(installLoc->GetFileAsync("cities.db")).then([](Windows::Storage::StorageFile^ file){
     auto db = ref new SQLiteWinRT::Database(file);

     task<void>(db->OpenAsync(SQLiteWinRT::SqliteOpenMode::OpenRead)).then([db](){
            task<SQLiteWinRT::Statement^>(db->PrepareStatementAsync("SELECT rowid, CityName FROM Cities;")).then([](SQLiteWinRT::Statement^ stmt){

                   while (bool res = task<bool>(stmt->StepAsync()).get()) {
                        if (res == true) {

                        }
                    }



            });
     });
});

---

在Actuto to Excice中，您将在循环中做任何事情。

< P>随着最新版本的发布，以及对可恢复和等待的支持，在这个版本中，C++代码现在看起来更容易读到下面的代码段：

void MainPage::DoStuff() __resumable
{
    auto items = ref new Vector<String^>();

    auto file = __await Package::Current->InstalledLocation->GetFileAsync("cities.db");
    auto db = ref new SQLiteWinRT::Database(file);
    __await db->OpenAsync(SQLiteWinRT::SqliteOpenMode::OpenRead);
    auto stmt = __await db->PrepareStatementAsync("SELECT rowid, CityName FROM Cities;");
    while (__await stmt->StepAsync())
        items->Append(stmt->GetIntAt(0) + ": " + stmt->GetTextAt(1));
}

---

我认为DatabasesCx更简单

---

或者你可以这样做：

task<void> stepInfoRecursive(std::function<void()> actionToExecute,SQLiteWinRT::Statement^ stmt)
{
    return task<bool>(stmt->StepAsync()).then([actionToExecute,stmt](bool ret){
                        actionToExecute();

                        if (ret){
                             return stepInfoRecursive(actionToExecute,stmt);
                        }
                        return create_task([]{});

                    });
}

auto installLoc = Windows::ApplicationModel::Package::Current->InstalledLocation;

task<Windows::Storage::StorageFile^>(installLoc->GetFileAsync("cities.db")).then([](Windows::Storage::StorageFile^ file){
     auto db = ref new SQLiteWinRT::Database(file);

     task<void>(db->OpenAsync(SQLiteWinRT::SqliteOpenMode::OpenRead)).then([db](){
            task<SQLiteWinRT::Statement^>(db->PrepareStatementAsync("SELECT rowid, CityName FROM Cities;")).then([](SQLiteWinRT::Statement^ stmt){

                   while (bool res = task<bool>(stmt->StepAsync()).get()) {
                        if (res == true) {

                        }
                    }



            });
     });
});

---

有关C++中异步的更多例子，请看一下这个博客文章：

auto installLoc = Windows::ApplicationModel::Package::Current->InstalledLocation;

task<Windows::Storage::StorageFile^>(installLoc->GetFileAsync("cities.db")).then([](Windows::Storage::StorageFile^ file){
     auto db = ref new SQLiteWinRT::Database(file);

     task<void>(db->OpenAsync(SQLiteWinRT::SqliteOpenMode::OpenRead)).then([db](){
            task<SQLiteWinRT::Statement^>(db->PrepareStatementAsync("SELECT rowid, CityName FROM Cities;")).then([](SQLiteWinRT::Statement^ stmt){

                   while (bool res = task<bool>(stmt->StepAsync()).get()) {
                        if (res == true) {

                        }
                    }



            });
     });
});