3

除了 Apple 的 Load Preset Demo 示例代码中包含的许多其他内容外，对 CFURLCreateDataAndPropertiesFromResource 的调用现在已被弃用。但是我找不到它的替代品——无论是单击选项还是查看参考资料都不会告诉我它不再是完成的事情。

CFDataRef propertyResourceData = 0;
Boolean status;
SInt32 errorCode = 0;
OSStatus result = noErr;

// Read from the URL and convert into a CFData chunk
status = CFURLCreateDataAndPropertiesFromResource (
                                                   kCFAllocatorDefault,
                                                   (__bridge CFURLRef) presetURL,
                                                   &propertyResourceData,
                                                   NULL,
                                                   NULL,
                                                   &errorCode
                                                   );


NSAssert (status == YES && propertyResourceData != 0, @"Unable to create data and properties from a preset. Error code: %d '%.4s'", (int) errorCode, (const char *)&errorCode);

// Convert the data object into a property list
CFPropertyListRef presetPropertyList = 0;
CFPropertyListFormat dataFormat = 0;
CFErrorRef errorRef = 0;
presetPropertyList = CFPropertyListCreateWithData (
                                                   kCFAllocatorDefault,
                                                   propertyResourceData,
                                                   kCFPropertyListImmutable,
                                                   &dataFormat,
                                                   &errorRef
                                                   );

// Set the class info property for the Sampler unit using the property list as the value.
if (presetPropertyList != 0) {

    result = AudioUnitSetProperty(
                                  self.samplerUnit,
                                  kAudioUnitProperty_ClassInfo,
                                  kAudioUnitScope_Global,
                                  0,
                                  &presetPropertyList,
                                  sizeof(CFPropertyListRef)
                                  );

    CFRelease(presetPropertyList);
}

if (errorRef) CFRelease(errorRef);
CFRelease (propertyResourceData);

return result;
4

3 回答 3

5

对于属性： CFURLCopyResourcePropertiesForKeys example property: kCFURLFileSizeKeyand kCFURLContentModificationDateKey，或 Foundation-style with [NSURL resourceValuesForKeys:error:]。

对于数据： +[NSData dataWithContentsOfURL:options:error:]。

他们没有记录为替代品，AFAIK。大多数这些更新的替代 API 已经存在了几年。

编辑

在您在编辑中发布的此示例中，程序不请求属性，因此您只需要 URL 中的数据presetURL。

您可以通过以下方式实现：

NSURL * presetURL = ...;
// do review these options for your needs. you can make great
// optimizations if you use memory mapping or avoid unnecessary caching.
const NSDataReadingOptions DataReadingOptions = 0;
NSError * outError = nil;
NSData * data = [NSData dataWithContentsOfURL:presetURL
                                      options:DataReadingOptions
                                        error:&outError];

const bool status = nil != data; // << your `status` variable

if (!status) {
 // oops - an error was encountered getting the data see `outError`
}
else {
 // use the data
}
于 2013-09-26T21:29:01.900 回答
0

我发现我可以使用以下内容删除更多代码：

OSStatus result = noErr;
NSData* data = [NSData dataWithContentsOfURL:presetURL];
id propertyList = [NSPropertyListSerialization propertyListWithData:data options:NSPropertyListImmutable format:NULL error:NULL];

// Set the class info property for the Sampler unit using the property list as the value.
if (propertyList) {
    result = AudioUnitSetProperty(
                                  self.samplerUnit,
                                  kAudioUnitProperty_ClassInfo,
                                  kAudioUnitScope_Global,
                                  0,
                                  (__bridge CFPropertyListRef)propertyList,
                                  sizeof(CFPropertyListRef)
                                  );
}

return result;
于 2014-11-11T16:51:14.760 回答
-1

我最终使用了这个代码https://developer.apple.com/library/mac/technotes/tn2283/_index.html#//apple_ref/doc/uid/DTS40011217-CH1-TNTAG2

- (OSStatus) loadSynthFromPresetURL: (NSURL *) presetURL {

OSStatus result = noErr;

AUSamplerInstrumentData auPreset = {0};

auPreset.fileURL = (__bridge CFURLRef) presetURL;
auPreset.instrumentType = kInstrumentType_AUPreset;

result = AudioUnitSetProperty(self.samplerUnit,
                              kAUSamplerProperty_LoadInstrument,
                              kAudioUnitScope_Global,
                              0,
                              &auPreset,
                              sizeof(auPreset));

return result;
于 2015-04-24T11:32:57.600 回答