感觉拖了好久，今天将Wait接口的总结补上，顺便把SearchCondition也捎带结了。
直接上图。

Wait方法含义：查看查询条件是否符合，若符合，则返回结果。若不符合，则继续等待，直至超时。
返回结果可能为UIObject2对象或者UIObject2对象列表，或者布尔类型。

其中，传参SearchCondition是一个抽象类，若想获取其实体对象，需要调用Until工具类。
该类提供了4个接口方法，来返回SearchCondition实体对象。

public static SearchCondition<UiObject2> findObject(final BySelector selector) 
public static SearchCondition<List<UiObject2>> findObjects(final BySelector selector) 
public static SearchCondition<Boolean> hasObject(final BySelector selector) 
public static SearchCondition<Boolean> gone(final BySelector selector) 

这里着重说一下gone方法（前三个方法，从方法名称便可理解用途）。

该方法与findObject功能相反。若不存在符合查询条件的UI对象，则返回true，否则返回false。

还是通过示例来说明如何使用。核心代码如下。

public class WaitTest extends UIDeviceTest {
    

    private String text_button1 ="OPEN ACTIVITY 2";

    private String text_button2 ="OPEN ACTIVITY";

    private String text_check="check";

    private String mPackageName="com.breakloop.test";

    private String mActivityName=".MainActivity";

    private long timeout=2000l;

    @Before
    public void start(){
        Utils.startAPP(mDevice,mPackageName,mActivityName);
        waitForAMoment();
    }

    private void waitForAMoment(){
        mDevice.waitForWindowUpdate(mPackageName,timeout);
    }

    @After
    public void end(){
        Utils.closeAPP(mDevice,mPackageName);
        waitForAMoment();
    }

    @Test
    public void Test1(){
        UiObject2 ui2=null;
        List<UiObject2> uiObject2List=null;
        boolean result=false;

        Log.i(TAG, "Test: start");
        ui2=mDevice.wait(Until.findObject(By.text(text_button1)),timeout);
        Log.i(TAG, "Test1: "+(ui2!=null?"":"Do Not ")+"find UI with txt "+text_button1);

        ui2=mDevice.wait(Until.findObject(By.text(text_button2)),timeout);
        Log.i(TAG, "Test2: "+(ui2!=null?"":"Do Not ")+"find UI with txt "+text_button2);

        result=mDevice.wait(Until.hasObject(By.text(text_button1)),timeout);
        Log.i(TAG, "Test3: "+(result?"":"Do Not ")+"find UI with txt "+text_button1);

        result=mDevice.wait(Until.hasObject(By.text(text_button2)),timeout);
        Log.i(TAG, "Test4: "+(result?"":"Do Not ")+"find UI with txt "+text_button2);

        result=mDevice.wait(Until.gone(By.text(text_button1)),timeout);
        Log.i(TAG, "Test5: "+(result?"Do Not ":"")+"find UI with txt "+text_button1);

        result=mDevice.wait(Until.gone(By.text(text_button2)),timeout);
        Log.i(TAG, "Test6: "+(result?"Do Not ":"")+"find UI with txt "+text_button2);

        uiObject2List=mDevice.wait(Until.findObjects(By.textStartsWith(text_check)),timeout);
        Log.i(TAG, "Test7: "+(uiObject2List!=null?"":"Do Not ")+"find UI with txt "+text_check);
        if(uiObject2List!=null){
            for (UiObject2 item :
                    uiObject2List) {
                item.click();
                waitForAMoment();
            }
        }

        uiObject2List=mDevice.wait(Until.findObjects(By.text(text_check)),timeout);
        Log.i(TAG, "Test8: "+(uiObject2List!=null?"":"Do Not ")+"find UI with txt "+text_check);
        if(uiObject2List!=null){
            for (UiObject2 item :
                    uiObject2List) {
                item.click();
                waitForAMoment();
            }
        }
        Log.i(TAG, "Test: end");
    }
}

执行效果如图

执行结果如下

15:48:58.700 I/com.breakloop.u2demo.uidevice.WaitTest: Test: start
15:48:58.748 I/com.breakloop.u2demo.uidevice.WaitTest: Test1: find UI with txt OPEN ACTIVITY 2
15:49:00.876 I/com.breakloop.u2demo.uidevice.WaitTest: Test2: Do Not find UI with txt OPEN ACTIVITY
15:49:00.939 I/com.breakloop.u2demo.uidevice.WaitTest: Test3: find UI with txt OPEN ACTIVITY 2
15:49:03.078 I/com.breakloop.u2demo.uidevice.WaitTest: Test4: Do Not find UI with txt OPEN ACTIVITY
15:49:05.209 I/com.breakloop.u2demo.uidevice.WaitTest: Test5: find UI with txt OPEN ACTIVITY 2
15:49:05.249 I/com.breakloop.u2demo.uidevice.WaitTest: Test6: Do Not find UI with txt OPEN ACTIVITY
15:49:05.290 I/com.breakloop.u2demo.uidevice.WaitTest: Test7: find UI with txt check
15:49:11.620 I/com.breakloop.u2demo.uidevice.WaitTest: Test8: Do Not find UI with txt check
15:49:11.620 I/com.breakloop.u2demo.uidevice.WaitTest: Test: end

由执行结果可见：

对于Until.findObject，Until.findObjects，Until.hasObject三个方法，若找到符合查询条件的UI，则Wait结束，否则继续Wait，直至超时。

对于Until.gone方法，则相反。若找到符合查询条件的UI，则继续Wait，直至超时，否则，Wait结束。