swift - 从何时捕获进度

Question

我的 Promise 用法看起来像 -

when(fulfilled: [promise]).then {(response) -> Void in


}.catch { (error) in
    print(error)
}

我正在尝试找出如何利用 when.swift 中的 progress 属性，但到目前为止还没有成功。提前致谢。

Answer 1

PromiseKit 本身就有一个例子:

https://github.com/mxcl/PromiseKit/blob/master/Tests/CorePromise/03_WhenTests.swift#L120-L141

func testProgress() {
    let ex = expectation(description: "")

    XCTAssertNil(Progress.current())

    let p1 = after(.milliseconds(10))
    let p2 = after(.milliseconds(20))
    let p3 = after(.milliseconds(30))
    let p4 = after(.milliseconds(40))

    let progress = Progress(totalUnitCount: 1)
    progress.becomeCurrent(withPendingUnitCount: 1)

    when(fulfilled: p1, p2, p3, p4).done { _ in
        XCTAssertEqual(progress.completedUnitCount, 1)
        ex.fulfill()
    }

    progress.resignCurrent()

    waitForExpectations(timeout: 1, handler: nil)
}