appium三种等待元素的方法

测试积点老人

学过selenium的都知道，一般等待元素加载有三种办法:
（1）sleep                  强制等待。示例：Thread.sleep（60000）
（2）implicitlyWait   隐式等待。全局等待30s不管元素是否已经加载

示例：driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);
（3）WebDriverWait     显示等待，这个需要增加一定等待时间，显示等待时间可以通过WebDriverWait 和util来决定,比如这个timeOut是60，如果该元素60s以内出现就不在等待

1. WebDriverWait wait = new WebDriverWait(driver, 60);
   
2.     WebElement e= wait.until(new  ExpectedCondition<WebElement>() {
   
3.             @Override
   
4.             public WebElement apply(WebDriver d) {
   
5.                 return d.findElement(By.id("q"));
   
6.             }
   
7.         })

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以上三种方法中，只用WebDriverWait是selenium所特有，在java-client中也找不到相应的，如果想使用这种方法怎么办？

改造轮子，首先添加AndroidDriverWait.java, 其实是将WebDriverWait的类型改成AndroidDriverWait

具体代码如下：

1. import org.openqa.selenium.NotFoundException;
   
2. import org.openqa.selenium.TimeoutException;
   
3. import org.openqa.selenium.WebDriver;
   
4. import org.openqa.selenium.WebDriverException;
   
5. import org.openqa.selenium.remote.RemoteWebDriver;
   
6. import org.openqa.selenium.support.ui.Clock;
   
7. import org.openqa.selenium.support.ui.FluentWait;
   
8. import org.openqa.selenium.support.ui.Sleeper;
   
9. import org.openqa.selenium.support.ui.SystemClock;
   
10. 
    
11. import io.appium.java_client.android.AndroidDriver;
    
12. 
    
13. import java.util.concurrent.TimeUnit;
    
14. 
    
15. /**
    
16.   * A specialization of {[url=home.php?mod=space&uid=26824]@link[/url] FluentWait} that uses WebDriver instances.
    
17.   */
    
18. public class AndroidDriverWait extends FluentWait<AndroidDriver> {
    
19.    public final static long DEFAULT_SLEEP_TIMEOUT = 500;
    
20.    private final WebDriver driver;
    
21. 
    
22.    /**
    
23.     * Wait will ignore instances of NotFoundException that are encountered (thrown) by default in
    
24.     * the 'until' condition, and immediately propagate all others.  You can add more to the ignore
    
25.     * list by calling ignoring(exceptions to add).
    
26.     *
    
27.     * @param driver The WebDriver instance to pass to the expected conditions
    
28.     * @param timeOutInSeconds The timeout in seconds when an expectation is called
    
29.     * @see AndroidDriverWait#ignoring(java.lang.Class)
    
30.     */
    
31.    public AndroidDriverWait(AndroidDriver driver, long timeOutInSeconds) {
    
32.      this(driver, new SystemClock(), Sleeper.SYSTEM_SLEEPER, timeOutInSeconds, DEFAULT_SLEEP_TIMEOUT);
    
33.    }
    
34. 
    
35.    /**
    
36.     * Wait will ignore instances of NotFoundException that are encountered (thrown) by default in
    
37.     * the 'until' condition, and immediately propagate all others.  You can add more to the ignore
    
38.     * list by calling ignoring(exceptions to add).
    
39.     *
    
40.     * @param driver The WebDriver instance to pass to the expected conditions
    
41.     * @param timeOutInSeconds The timeout in seconds when an expectation is called
    
42.     * @param sleepInMillis The duration in milliseconds to sleep between polls.
    
43.     * @see AndroidDriverWait#ignoring(java.lang.Class)
    
44.     */
    
45.    public AndroidDriverWait(AndroidDriver driver, long timeOutInSeconds, long sleepInMillis) {
    
46.      this(driver, new SystemClock(), Sleeper.SYSTEM_SLEEPER, timeOutInSeconds, sleepInMillis);
    
47.    }
    
48. 
    
49.    /**
    
50.     * @param driver The WebDriver instance to pass to the expected conditions
    
51.     * @param clock The clock to use when measuring the timeout
    
52.     * @param sleeper Object used to make the current thread go to sleep.
    
53.     * @param timeOutInSeconds The timeout in seconds when an expectation is
    
54.     * @param sleepTimeOut The timeout used whilst sleeping. Defaults to 500ms called.
    
55.     */
    
56.    public AndroidDriverWait(AndroidDriver driver, Clock clock, Sleeper sleeper, long timeOutInSeconds,
    
57.        long sleepTimeOut) {
    
58.      super(driver, clock, sleeper);
    
59.      withTimeout(timeOutInSeconds, TimeUnit.SECONDS);
    
60.      pollingEvery(sleepTimeOut, TimeUnit.MILLISECONDS);
    
61.      ignoring(NotFoundException.class);
    
62.      this.driver = driver;
    
63.    }
    
64. 
    
65.    @Override
    
66.    protected RuntimeException timeoutException(String message, Throwable lastException) {
    
67.      TimeoutException ex = new TimeoutException(message, lastException);
    
68.      ex.addInfo(WebDriverException.DRIVER_INFO, driver.getClass().getName());
    
69.      if (driver instanceof RemoteWebDriver) {
    
70.        RemoteWebDriver remote = (RemoteWebDriver) driver;
    
71.        if (remote.getSessionId() != null) {
    
72.          ex.addInfo(WebDriverException.SESSION_ID, remote.getSessionId().toString());
    
73.        }
    
74.        if (remote.getCapabilities() != null) {
    
75.          ex.addInfo("Capabilities", remote.getCapabilities().toString());
    
76.        }
    
77.      }
    
78.      throw ex;
    
79.    }
    
80. }

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接着需要修改接口：ExpectedCondition，将其WebDriver的类型替换为AndroidDriver

具体代码：

public interface ExpectedCondition<T> extends Function<AndroidDriver, T> {}

经过修改之后，就可以在appium中直接使用：

1. //wait for 60s if WebElemnt show up less than 60s , then return , until 60s
   
2.         WebElement showClose = new AndroidDriverWait(driver, 60)
   
3.                 .until(new ExpectedCondition<WebElement>() {
   
4.                     public WebElement apply(AndroidDriver d) {
   
5.                         return d.findElement(By
   
6.                                 .id("com.zhihu.android:id/showcase_close"));
   
7.                     }
   
8. 
   
9.                 });

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