下面的代码只适用于Objective C。

- (void)wait:(NSUInteger)interval {

    XCTestExpectation *expectation = [self expectationWithDescription:@"wait"];
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(interval * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        [expectation fulfill];
    });
    [self waitForExpectationsWithTimeout:interval handler:nil];
}

只需调用这个函数，如下所示。

[self wait: 10];

iOS 11 / Xcode 9

<#yourElement#>.waitForExistence(timeout: 5)

这是一个伟大的替代所有自定义实现在这个网站!

一定要看看我的答案:https://stackoverflow.com/a/48937714/971329。在这里，我描述了一种替代等待请求的方法，它将大大减少测试运行的时间!

基于@Ted的回答，我使用了这个扩展:

extension XCTestCase {

    // Based on https://stackoverflow.com/a/33855219
    func waitFor<T>(object: T, timeout: TimeInterval = 5, file: String = #file, line: UInt = #line, expectationPredicate: @escaping (T) -> Bool) {
        let predicate = NSPredicate { obj, _ in
            expectationPredicate(obj as! T)
        }
        expectation(for: predicate, evaluatedWith: object, handler: nil)

        waitForExpectations(timeout: timeout) { error in
            if (error != nil) {
                let message = "Failed to fulful expectation block for \(object) after \(timeout) seconds."
                let location = XCTSourceCodeLocation(filePath: file, lineNumber: line)
                let issue = XCTIssue(type: .assertionFailure, compactDescription: message, detailedDescription: nil, sourceCodeContext: .init(location: location), associatedError: nil, attachments: [])
                self.record(issue)
            }
        }
    }

}

你可以这样用

let element = app.staticTexts["Name of your element"]
waitFor(object: element) { $0.exists }

它还允许等待元素消失或任何其他属性更改(通过使用适当的块)

waitFor(object: element) { !$0.exists } // Wait for it to disappear

从Xcode 8.3开始，我们可以使用XCTWaiter http://masilotti.com/xctest-waiting/

func waitForElementToAppear(_ element: XCUIElement) -> Bool {
    let predicate = NSPredicate(format: "exists == true")
    let expectation = expectation(for: predicate, evaluatedWith: element, 
                                  handler: nil)

    let result = XCTWaiter().wait(for: [expectation], timeout: 5)
    return result == .completed
}

另一个技巧是写一个等待函数，感谢John Sundell给我演示了它

extension XCTestCase {

  func wait(for duration: TimeInterval) {
    let waitExpectation = expectation(description: "Waiting")

    let when = DispatchTime.now() + duration
    DispatchQueue.main.asyncAfter(deadline: when) {
      waitExpectation.fulfill()
    }

    // We use a buffer here to avoid flakiness with Timer on CI
    waitForExpectations(timeout: duration + 0.5)
  }
}

然后像这样使用它

func testOpenLink() {
  let delegate = UIApplication.shared.delegate as! AppDelegate
  let route = RouteMock()
  UIApplication.shared.open(linkUrl, options: [:], completionHandler: nil)

  wait(for: 1)

  XCTAssertNotNil(route.location)
}

Xcode测试

在我的情况下，睡眠会产生副作用，所以我使用等待

let _ = XCTWaiter.wait(for: [XCTestExpectation(description: "Hello World!")], timeout: 2.0)

下面的代码只适用于Objective C。

- (void)wait:(NSUInteger)interval {

    XCTestExpectation *expectation = [self expectationWithDescription:@"wait"];
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(interval * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        [expectation fulfill];
    });
    [self waitForExpectationsWithTimeout:interval handler:nil];
}

只需调用这个函数，如下所示。

[self wait: 10];