我如何打印结果像0.0045

Question

     I only get this 

1667785316

1667785316

1667785316

     Float32 preferredBufferSize = 0.005; // 5 millis buffer
  UInt32 size = sizeof(preferredBufferSize);


    AudioSessionGetProperty(kAudioSessionProperty_CurrentHardwareIOBufferDuration, &size,
                &preferredBufferSize);
   printf("\n%d", kAudioSessionProperty_CurrentHardwareIOBufferDuration);

如果

        printf("\n%.4f", kAudioSessionProperty_CurrentHardwareIOBufferDuration);

我明白了 736204793259769514805539544958332881185808905380376591296729466482703872896792123284994544877461533270472921226586720994654163338779026978512060081697113376452636514975744.0000 736204793259769514805539544958332881185808905380376591296729466482703872896792123284994544877461533270472921226586720994654163338779026978512060081697113376452636514975744.0000

Answer 1

您正在使用整数符号。请改用浮点数。

printf("\n%.4f", kAudioSessionProperty_CurrentHardwareIOBufferDuration);

Answer 2

为什么要打印属性ID而不是值？ 如果你想打印你的毫秒，你可以这样做：

Float32 currentBufferSize; 
UInt32 size = sizeof(currentBufferSize);
AudioSessionGetProperty(kAudioSessionProperty_CurrentHardwareIOBufferDuration, 
                        &size,
                        &currentBufferSize);
printf("\n%.4f", currentBufferSize);

Answer 3

printf("\n%.4f", kAudioSessionProperty_CurrentHardwareIOBufferDuration);

如果要在32位浮点数上使用4位小数精度。如果你想要任意长度，请删除.4。

Answer 4

%d表示整数，使用%f表示float或double。阅读String Format Specifiers。