上一篇文章：
Android自動化測試--Instrumented Unit Tests使用
相比上一篇文章所講的Instrumented Unit Tests，本文所講的自動化測試Espresso最顯著的特點就是，可以與UI相交互。
使用
首先我們在Android Studio中新建一個項目，取名為EspressoTests。同時刪除自動生成的一些文件，最終目錄結構如下：
目錄結構
接下來我們看看如何一步一步的使用Espresso，首先在?根目錄的 build.gradle 文件中添加下面的引入。
ext {
buildToolsVersion = "24.0.1"
supportLibVersion = "24.2.0"
espressoVersion = "2.2.2"
}
在app目錄中的build.gradle 文件中添加下面的引入，根據提示點擊Sync Now。
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
// App dependencies
compile 'com.android.support:appcompat-v7:' + rootProject.supportLibVersion;
compile 'com.android.support:support-annotations:' + rootProject.supportLibVersion;
compile 'com.android.support:recyclerview-v7:' + rootProject.supportLibVersion;
androidTestCompile 'com.android.support.test.espresso:espresso-core:' + rootProject.espressoVersion;
androidTestCompile('com.android.support.test.espresso:espresso-contrib:' + rootProject.espressoVersion) {
transitive false
};
androidTestCompile 'com.android.support.test.espresso:espresso-web:' + rootProject.espressoVersion;
androidTestCompile 'com.android.support:support-annotations:' + rootProject.supportLibVersion;
androidTestCompile 'com.android.support:recyclerview-v7:' + rootProject.supportLibVersion;
}
接下來我們編寫測試例子，最終的結果如下：
Paste_Image.png
其中MainActivity界面如下，輸入框中點擊數字后點擊計算可以在結果處顯示兩者相加的值，點擊webview跳轉到WebViewActivity，點擊recycleview跳轉到RecycleViewActivity。
MainActivity
其中WebViewActivity中包含一個webview，可以加載跳轉傳過來的url。
WebViewActivity
其中RecycleViewActivity就是一個recycleview的簡單使用，實現了一個列表。
RecycleViewActivity
接下來我們看看測試的代碼，在代碼中又詳細的注釋。
package me.shihao.instrumentedunittests;
import android.support.test.espresso.Espresso;
import android.support.test.espresso.contrib.RecyclerViewActions;
import android.support.test.espresso.matcher.ViewMatchers;
import android.support.test.espresso.web.assertion.WebViewAssertions;
import android.support.test.espresso.web.webdriver.DriverAtoms;
import android.support.test.espresso.web.webdriver.Locator;
import android.support.test.rule.ActivityTestRule;
import android.support.test.runner.AndroidJUnit4;
import org.hamcrest.Matchers;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import me.shihao.espressotests.MainActivity;
import me.shihao.espressotests.R;
import static android.support.test.espresso.action.ViewActions.click;
import static android.support.test.espresso.action.ViewActions.closeSoftKeyboard;
import static android.support.test.espresso.action.ViewActions.typeText;
import static android.support.test.espresso.assertion.ViewAssertions.matches;
import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
import static android.support.test.espresso.matcher.ViewMatchers.withId;
import static android.support.test.espresso.matcher.ViewMatchers.withText;
import static android.support.test.espresso.web.sugar.Web.onWebView;
import static android.support.test.espresso.web.webdriver.DriverAtoms.findElement;
import static android.support.test.espresso.web.webdriver.DriverAtoms.webClick;
/**
* Created by shihao on 2017/3/2.
*/
@RunWith(AndroidJUnit4.class)
public class MainActivityTest {
@Rule
public ActivityTestRule activityTestRule = new ActivityTestRule(MainActivity.class);
@Test
public void test() {
//通過id找到edittext，在里面輸入2并關閉輸入法
Espresso.onView(withId(R.id.editText)).perform(typeText("2"), closeSoftKeyboard());
//通過id找到edittext，在里面輸入5并關閉輸入法
Espresso.onView(withId(R.id.editText2)).perform(typeText("5"), closeSoftKeyboard());
//通過id找到button，執行點擊事件
Espresso.onView(withId(R.id.button)).perform(click());
//通過id找到textview，并判斷是否與文本匹配
Espresso.onView(withId(R.id.textView)).check(matches(withText("計算結果：6")));
Espresso.onView(withId(R.id.textView)).check(matches(withText("計算結果：7")));
}
@Test
public void testRecycleView() {
//通過文本RecycleView找到按鈕，并執行點擊事件，跳轉到RecycleviewActivity
Espresso.onView(withText("RecycleView")).perform(click());
//通過文本"Item 0"找到view，并檢查是否顯示，然后執行點擊事件 ，此時會彈出對話框
Espresso.onView(withText("Item 0")).check(matches(isDisplayed())).perform(click());
//通過文本"確定"找到對話框上的確定按鈕，執行點擊事件，關閉對話框
Espresso.onView(withText("確定")).perform(click());
//通過文本"Item 2"找到view，并檢查是否顯示，然后執行點擊事件，此時會彈出對話框
Espresso.onView(withText("Item 2")).check(matches(isDisplayed())).perform(click());
//執行點擊返回按鈕事件，關閉對話框
Espresso.pressBack();
//通過id找到recycleview，然后執行滑動事件，滑動到21項
Espresso.onView(ViewMatchers.withId(R.id.recycleview)).perform(RecyclerViewActions.scrollToPosition(21));
//通過文本"Item 20"找到view，并檢查是否顯示，然后執行點擊事件，此時會彈出對話框
Espresso.onView(withText("Item 20")).check(matches(isDisplayed())).perform(click());
//通過文本"確定"找到對話框上的確定按鈕，執行點擊事件，關閉對話框
Espresso.onView(withText("確定")).perform(click());
//執行點擊返回按鈕事件，關閉跳轉到RecycleviewActivity
Espresso.pressBack();
}
@Test
public void testWebView() {
//通過文本RecycleView找到按鈕，并執行點擊事件，跳轉到WebViewActivity
Espresso.onView(withText("WebView")).perform(click());
//通過name為"word"找到搜索輸入框
onWebView().withElement(findElement(Locator.NAME, "word"))
//往輸入框中輸入字符串"android"
.perform(DriverAtoms.webKeys("android"))
//通過id為"index-bn"找到"百度一下"按鈕
.withElement(DriverAtoms.findElement(Locator.ID, "index-bn"))
//執行點擊事件
.perform(webClick())
//通過id為"results"找到結果div
.withElement(DriverAtoms.findElement(Locator.ID, "results"))
//檢查div中是否包含字符串"android"
.check(WebViewAssertions.webMatches(DriverAtoms.getText(), Matchers.containsString("android")));
//執行點擊返回按鈕事件，關閉跳轉到WebViewActivity
Espresso.pressBack();
}
}
package me.shihao.instrumentedunittests;
import android.content.Intent;
import android.support.test.espresso.web.action.AtomAction;
import android.support.test.espresso.web.assertion.WebViewAssertions;
import android.support.test.espresso.web.sugar.Web;
import android.support.test.espresso.web.webdriver.DriverAtoms;
import android.support.test.espresso.web.webdriver.Locator;
import android.support.test.rule.ActivityTestRule;
import android.support.test.runner.AndroidJUnit4;
import org.hamcrest.Matchers;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import me.shihao.espressotests.WebViewActivity;
import static android.support.test.espresso.web.sugar.Web.onWebView;
import static android.support.test.espresso.web.webdriver.DriverAtoms.findElement;
import static android.support.test.espresso.web.webdriver.DriverAtoms.webClick;
import static org.hamcrest.Matchers.containsString;
/**
* Created by shihao on 2017/3/3.
*/
@RunWith(AndroidJUnit4.class)
public class WebViewActivityTest {
@Rule
public ActivityTestRule activityTestRule = new ActivityTestRule(WebViewActivity.class, false);
@Test
public void test() {
//傳遞數據到WebViewActivity
Intent intent = new Intent();
intent.putExtra(WebViewActivity.EXTRA_URL, "http://m.baidu.com");
activityTestRule.launchActivity(intent);
//通過name為"word"找到搜索輸入框
onWebView().withElement(findElement(Locator.NAME, "word"))
//往輸入框中輸入字符串"android"
.perform(DriverAtoms.webKeys("android"))
//通過id為"index-bn"找到"百度一下"按鈕
.withElement(DriverAtoms.findElement(Locator.ID, "index-bn"))
//執行點擊事件
.perform(webClick())
//通過id為"results"找到結果div
.withElement(DriverAtoms.findElement(Locator.ID, "results"))
//檢查div中是否包含字符串"android"
.check(WebViewAssertions.webMatches(DriverAtoms.getText(), Matchers.containsString("android")));
}
}
接下來我們運行測試一下MainActivityTest，看看效果如何
測試結果
測試結果與我們預期的一樣，有一個不匹配。手機運行效果如下：
運行效果.gif
接下來我們就看一看如何在測試中與多個應用界面相交互，歡迎查看下一篇文章：
