在上一篇Uiautomator測試----系統測試是通過Uiautomatorviewer工具來搜尋查詢，當控制元件含有搜尋字元時 唯一時，容易定位及編寫程式碼如：

new UiSelector().className("android.widget.TextView").textContains("地圖").resourceId("com.android.launch")

但遇到太多的view\RelativeLayout等父控制元件，子控制元件沒有明顯的搜尋關鍵字/ID時，則需一級一級進行編寫測試程式碼。

當應用開源已知每一個元件的id(開發使用findViewById來操作)，則可直接針對ID進行搜尋查詢，同樣達到測試的目的

 mDevice.findObject(By.res("<span style="color: rgb(24, 54, 145); font-family: Consolas, 'Liberation Mono', Menlo, Courier, monospace; line-height: 16.8px; white-space: pre;">com.example.android.testing.uiautomator.BasicSample</span>", "<strong>changeTextBt</strong>"))
                .click();
 

<strong>changeTextBt 為該控制元件的ID名稱</strong>

例：

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.support.test.InstrumentationRegistry;
import android.support.test.filters.SdkSuppress;
import android.support.test.runner.AndroidJUnit4;
import android.support.test.uiautomator.By;
import android.support.test.uiautomator.UiDevice;
import android.support.test.uiautomator.UiObject2;
import android.support.test.uiautomator.Until;

import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.CoreMatchers.notNullValue;
import static org.junit.Assert.assertThat;

/**
 * Basic sample for unbundled UiAutomator.
 */
@RunWith(AndroidJUnit4.class)
@SdkSuppress(minSdkVersion = 18)
public class ChangeTextBehaviorTest {

    private static final String BASIC_SAMPLE_PACKAGE
            = "com.example.android.testing.uiautomator.BasicSample";

    private static final int LAUNCH_TIMEOUT = 5000;

    private static final String STRING_TO_BE_TYPED = "UiAutomator";

    private UiDevice mDevice;

    @Before
    public void startMainActivityFromHomeScreen() {
        // Initialize UiDevice instance
        mDevice = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation());

        // Start from the home screen
        mDevice.pressHome();

        // Wait for launcher
        final String launcherPackage = getLauncherPackageName();
        assertThat(launcherPackage, notNullValue());
        mDevice.wait(Until.hasObject(By.pkg(launcherPackage).depth(0)), LAUNCH_TIMEOUT);

        // Launch the blueprint app
        Context context = InstrumentationRegistry.getContext();
        final Intent intent = context.getPackageManager()
                .getLaunchIntentForPackage(BASIC_SAMPLE_PACKAGE);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);    // Clear out any previous instances
        context.startActivity(intent);

        // Wait for the app to appear
        mDevice.wait(Until.hasObject(By.pkg(BASIC_SAMPLE_PACKAGE).depth(0)), LAUNCH_TIMEOUT);
    }

    @Test
    public void checkPreconditions() {
        assertThat(mDevice, notNullValue());
    }

    @Test
    public void testChangeText_sameActivity() {
        // Type text and then press the button.
        mDevice.findObject(By.res(BASIC_SAMPLE_PACKAGE, "editTextUserInput"))
                .setText(STRING_TO_BE_TYPED);
        mDevice.findObject(By.res(BASIC_SAMPLE_PACKAGE, "changeTextBt"))
                .click();

        // Verify the test is displayed in the Ui
        UiObject2 changedText = mDevice
                .wait(Until.findObject(By.res(BASIC_SAMPLE_PACKAGE, "textToBeChanged")),
                        500 /* wait 500ms */);
        assertThat(changedText.getText(), is(equalTo(STRING_TO_BE_TYPED)));
    }

    @Test
    public void testChangeText_newActivity() {
        // Type text and then press the button.
        mDevice.findObject(By.res(BASIC_SAMPLE_PACKAGE, "editTextUserInput"))
                .setText(STRING_TO_BE_TYPED);
        mDevice.findObject(By.res(BASIC_SAMPLE_PACKAGE, "activityChangeTextBtn"))
                .click();

        // Verify the test is displayed in the Ui
        UiObject2 changedText = mDevice
                .wait(Until.findObject(By.res(BASIC_SAMPLE_PACKAGE, "show_text_view")),
                        500 /* wait 500ms */);
        assertThat(changedText.getText(), is(equalTo(STRING_TO_BE_TYPED)));
    }

    /**
     * Uses package manager to find the package name of the device launcher. Usually this package
     * is "com.android.launcher" but can be different at times. This is a generic solution which
     * works on all platforms.`
     */
    private String getLauncherPackageName() {
        // Create launcher Intent
        final Intent intent = new Intent(Intent.ACTION_MAIN);
        intent.addCategory(Intent.CATEGORY_HOME);

        // Use PackageManager to get the launcher package name
        PackageManager pm = InstrumentationRegistry.getContext().getPackageManager();
        ResolveInfo resolveInfo = pm.resolveActivity(intent, PackageManager.MATCH_DEFAULT_ONLY);
        return resolveInfo.activityInfo.packageName;
    }
}