Question

我正在尝试从这里CTFrameGetLineOrigins Got Incorrect Origins中找出CTFrameGetLineOrigins，并尝试将ObjC转换为Swift。

Obj-C：

CFArrayRef lines = CTFrameGetLines(frame);
size_t numOfLines = CFArrayGetCount(lines);
CGPoint lineOrigins[numOfLines];
CTFrameGetLineOrigins(frame, CFRangeMake(0, 0), lineOrigins);

迅速：

let lines = CTFrameGetLines(frame)
let numOfLines: size_t = CFArrayGetCount(lines)
let lineOrigins = [CGPoint](repeating: CGPoint.zero, count: numOfLines)
CTFrameGetLineOrigins(frame, CFRangeMake(0, 0), lineOrigins)

但是我遇到了CTFrameGetLineOrigins的第三个参数错误：
无法将类型“ [CGPoint]”的值转换为预期的参数类型“ UnsafeMutablePointer”

如何克服此错误？

Answer 1

实际上，我只是将var arr = [{a:1, b:2, c:3, d:4}, {a:1, x:2, y:3, z:4}, {a:1, x:2, y:3, z:4}]; let result = arr.every((obj)=> obj.a === 1); console.log(result);//true arr = [{a:1, b:2, c:3, d:4}, {a:1, x:2, y:3, z:4}, {a:2, x:2, y:3, z:4}]; result = arr.every((obj)=> obj.a === 1); console.log(result);//false //Checks whether all the a keys is same in the array of objects. result = arr.every((obj)=> obj.a === arr[0].a); console.log(result); //false arr = [{a:1, b:2, c:3, d:4}, {a:1, x:2, y:3, z:4}, {a:1, x:2, y:3, z:4}]; result = arr.every((obj)=> obj.a === arr[0].a); console.log(result); //true添加到参数中，并将常量设为变量。

Answer 2

您可以尝试

CTFrameGetLineOrigins(frame, CFRangeMake(0, 0), UnsafeMutablePointer(&lineOrigins))

或直接

CTFrameGetLineOrigins(frame, CFRangeMake(0, 0),&lineOrigins)

您如何满足Swift中CTFrameGetLineOrigins（）中的'lineOrigins'参数？

2 个答案: