objective-c - objc 结构数组到 swift 数组

Question

-(CGPoint*)func
{
    CGPoint* result = calloc(2, sizeof(CGPoint));
    result[0] = ..;
    result[1] = ..;

    return result;
}

如何将这个数组转换为 swift [CGPoint]？

Answer 1

您可以使用 UnsafeBufferPointer如下所示

    let pointer: UnsafeMutablePointer<CGPoint> = yourInstance.func()

    let swiftArray = Array(UnsafeBufferPointer(start: pointer, count: 2))

    free(pointer)

编辑

如果您真的需要使用 C 数组，您可能需要将 func 方法重写为如下内容:

- (CGPoint*)pointArray:(NSInteger *)length
{
    int arrSize = 2;
    CGPoint* result = calloc(arrSize, sizeof(CGPoint));
    result[0] = ...
    result[1] = ...

    *length = arrSize;

    return result;
}

然后在 Swift 方面:

    var arrayLength: Int = 0
    let pointer: UnsafeMutablePointer<CGPoint> = yourInstance.pointArray(&arrayLength)

    let swiftArray = Array(UnsafeBufferPointer(start: pointer, count: arrayLength))

    free(pointer)