appium三种等待元素的方法

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

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

  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：

 import org.openqa.selenium.NotFoundException; import org.openqa.selenium.TimeoutException; import org.openqa.selenium.WebDriver; import org.openqa.selenium.WebDriverException; import org.openqa.selenium.remote.RemoteWebDriver; import org.openqa.selenium.support.ui.Clock; import org.openqa.selenium.support.ui.FluentWait; import org.openqa.selenium.support.ui.Sleeper; import org.openqa.selenium.support.ui.SystemClock;  import io.appium.java_client.android.AndroidDriver;  import java.util.concurrent.TimeUnit;  /**  * A specialization of {@link FluentWait} that uses WebDriver instances.  */ public class AndroidDriverWait extends FluentWait<AndroidDriver> {   public final static long DEFAULT_SLEEP_TIMEOUT = 500;   private final WebDriver driver;    /**    * Wait will ignore instances of NotFoundException that are encountered (thrown) by default in    * the 'until' condition, and immediately propagate all others.  You can add more to the ignore    * list by calling ignoring(exceptions to add).    *    * @param driver The WebDriver instance to pass to the expected conditions    * @param timeOutInSeconds The timeout in seconds when an expectation is called    * @see AndroidDriverWait#ignoring(java.lang.Class)    */   public AndroidDriverWait(AndroidDriver driver, long timeOutInSeconds) {     this(driver, new SystemClock(), Sleeper.SYSTEM_SLEEPER, timeOutInSeconds, DEFAULT_SLEEP_TIMEOUT);   }    /**    * Wait will ignore instances of NotFoundException that are encountered (thrown) by default in    * the 'until' condition, and immediately propagate all others.  You can add more to the ignore    * list by calling ignoring(exceptions to add).    *    * @param driver The WebDriver instance to pass to the expected conditions    * @param timeOutInSeconds The timeout in seconds when an expectation is called    * @param sleepInMillis The duration in milliseconds to sleep between polls.    * @see AndroidDriverWait#ignoring(java.lang.Class)    */   public AndroidDriverWait(AndroidDriver driver, long timeOutInSeconds, long sleepInMillis) {     this(driver, new SystemClock(), Sleeper.SYSTEM_SLEEPER, timeOutInSeconds, sleepInMillis);   }    /**    * @param driver The WebDriver instance to pass to the expected conditions    * @param clock The clock to use when measuring the timeout    * @param sleeper Object used to make the current thread go to sleep.    * @param timeOutInSeconds The timeout in seconds when an expectation is    * @param sleepTimeOut The timeout used whilst sleeping. Defaults to 500ms called.    */   public AndroidDriverWait(AndroidDriver driver, Clock clock, Sleeper sleeper, long timeOutInSeconds,       long sleepTimeOut) {     super(driver, clock, sleeper);     withTimeout(timeOutInSeconds, TimeUnit.SECONDS);     pollingEvery(sleepTimeOut, TimeUnit.MILLISECONDS);     ignoring(NotFoundException.class);     this.driver = driver;   }    @Override   protected RuntimeException timeoutException(String message, Throwable lastException) {     TimeoutException ex = new TimeoutException(message, lastException);     ex.addInfo(WebDriverException.DRIVER_INFO, driver.getClass().getName());     if (driver instanceof RemoteWebDriver) {       RemoteWebDriver remote = (RemoteWebDriver) driver;       if (remote.getSessionId() != null) {         ex.addInfo(WebDriverException.SESSION_ID, remote.getSessionId().toString());       }       if (remote.getCapabilities() != null) {         ex.addInfo("Capabilities", remote.getCapabilities().toString());       }     }     throw ex;   } }

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：

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