iPhone - Apple doc中的iOS兼容性

Question

我可以在苹果doc中读到NSData：

- (BOOL)writeToFile:(NSString *)path options:(NSDataWritingOptions)mask error:(NSError **)errorPtr
Parameters

mask
A mask that specifies options for writing the data. Constant components are described in “NSDataWritingOptions”.

Available in iOS 2.0 and later.

和NSDataWritingOptions：

Options for methods used to write NSData objects.

enum {
   NSDataWritingAtomic = 1UL << 0,
   NSDataWritingCoordinated = 1UL << 2,
   NSDataWritingFileProtectionNone     = 0x10000000,
   NSDataWritingFileProtectionComplete = 0x20000000,
   NSDataWritingFileProtectionMask     = 0xf0000000,
};
typedef NSUInteger NSDataWritingOptions;

NSDataWritingAtomic
Available in iOS 4.0 and later.

NSDataWritingCoordinated
??????

NSDataWritingFileProtectionNone
Available in iOS 4.0 and later.

NSDataWritingFileProtectionComplete
Available in iOS 4.0 and later.

NSDataWritingFileProtectionMask
Available in iOS 4.0 and later.

在编译3.x target ???

时，如何使用2.0方法，该方法需要4.0参数

Answer 1

您应该能够以2.0的方式为3.x目标调用该方法。您将无法使用4.0格式或值来调用它。