如何修复JUCE中的Midi inputfilestream错误？

Question

我正在尝试在JUCE中将midi文件读取为一个序列，但是当我运行它时，出现错误，表明我的输入文件流有问题。

我从音频应用程序模板开始，并在getNextBlock（）函数中编写了midi读取代码。

File midiPath("/Desktop/input.midi");
FileInputStream myStream(midiPath);
MidiFile midifile;
midifile.readFrom(myStream);
int NumofTrack = midifile.getNumTracks();
std::cout<<"The track number:"<<NumofTrack<<std::end;

我只想在JUCE中测试readin函数，但它不起作用。错误显示为“ juce_FileInputStream.cpp”：

int64 FileInputStream::getTotalLength()
{
    // You should always check that a stream opened successfully before using it!
    jassert (openedOk());              <--  errror here
    ...

Answer 1

尝试：

File midiPath = File::getSpecialLocation(File::SpecialLocationType::userDesktopDirectory).getChildFile("input.midi");
FileInputStream myStream(midiPath);
MidiFile midifile;
midifile.readFrom(myStream);
int NumofTrack = midifile.getNumTracks();
std::cout<<"The track number:"<<NumofTrack<<std::end;