以下为activity_mian代码：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="com.example.gxd.hellowordhw.MainActivity"    android:orientation="vertical">

    <TextView        android:id="@+id/textview"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="Hello World!" />

    <EditText

        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:id="@+id/editText" />

    <Button        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="SAY HELLO!"        android:id="@+id/button"        android:layout_gravity="center_horizontal" />

</LinearLayout>

以下为Mainactivity代码：

package com.example.gxd.hellowordhw;

import android.support.v7.app.AppCompatActivity;        import android.os.Bundle;        import android.view.View;        import android.widget.EditText;        import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }

    public void sayHello(View view){        TextView textView=(TextView)findViewById(R.id.textview);        EditText editText=(EditText)findViewById(R.id.editText);        textView.setText("Hello,"+editText.getText().toString()+"!");    }}

以下为MainactivityText代码：public class MainActivityTest {     private static final String STRING_TO_BE_TYPEDTO = "Peter";    @Rule    public ActivityTestRule<MainActivity> mActivityTestRule = new ActivityTestRule<>(MainActivity.class);

    @Test    public void testSayHello() throws Exception {

        onView(withId(R.id.editText)).perform(TestRule(STRING_TO_BE_TYPEDTO),closeSoftKeyboard);        onView(withId(R.id.button)).perform(click());        String expectedText="Hello,"+ STRING_TO_BE_TYPEDTO +"!";        onView(withId(R.id.textview)).check(matches(withText(expectedText)));

    }

}

以下为build.gradle代码：

apply plugin: 'com.android.application'

android {    compileSdkVersion 23    buildToolsVersion "24.0.2"

    defaultConfig {        applicationId "com.example.gxd.hellowordhw"        minSdkVersion 19        targetSdkVersion 23        versionCode 1        versionName "1.0"        //add for test        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"    }    buildTypes {        release {            minifyEnabled false            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'        }    }}

dependencies {    compile fileTree(dir: 'libs', include: ['*.jar'])    testCompile 'junit:junit:4.12'    compile 'com.android.support:appcompat-v7:23.4.0'    //add for test    androidTestCompile 'com.android.support.test.espresso:espresso-core:2.2.2', {        exclude group: 'com.android.support', module: 'support-annotations'    }}布局：