通过 Macrobenchmark 控制应用

与大多数 Android 界面测试不同，Macrobenchmark 测试在独立于应用本身的进程中运行。必须这样做才能实现停止应用进程和从 DEX 字节码编译到机器码等目的。

您可以使用 UIAutomator 库或其他可以在测试进程中控制目标应用的机制来驱动应用的状态。您不能将 Espresso 或 ActivityScenario 用于 Macrobenchmark，因为它们需要在与应用共享的进程中运行。

以下示例会使用资源 ID 查找 RecyclerView，然后向下滚动几次：

Kotlin

@Test
fun scrollList() {
    benchmarkRule.measureRepeated(
        // ...
        setupBlock = {
            // Before starting to measure, navigate to the UI to be measured
            val intent = Intent("$packageName.RECYCLER_VIEW_ACTIVITY")
            startActivityAndWait(intent)
        }
    ) {
        val recycler = device.findObject(By.res(packageName, "recycler"))
        // Set gesture margin to avoid triggering gesture navigation
        // with input events from automation.
        recycler.setGestureMargin(device.displayWidth / 5)

        // Scroll down several times
        repeat(3) { recycler.fling(Direction.DOWN) }
    }
}
FrameTimingBenchmark.kt

Java

@Test
public void scrollList() {
    benchmarkRule.measureRepeated(
        // ...
        /* setupBlock */ scope -> {
            // Before measuring, navigate to the UI to be measured.
            val intent = Intent("$packageName.RECYCLER_VIEW_ACTIVITY")
            scope.startActivityAndWait();
            return Unit.INSTANCE;
        },
        /* measureBlock */ scope -> {
            UiDevice device = scope.getDevice();
            UiObject2 recycler = device.findObject(By.res(scope.getPackageName(), "recycler"));

            // Set gesture margin to avoid triggering gesture navigation
            // with input events from automation.
            recycler.setGestureMargin(device.getDisplayWidth() / 5);

            // Fling the recycler several times.
            for (int i = 0; i < 3; i++) {
                recycler.fling(Direction.DOWN);
            }

            return Unit.INSTANCE;
        }
    );
}

基准测试并不一定要滚动界面。不过，举例来说，它可以运行动画。此外，它也不需要特地使用 UI Automator。只要帧是由视图系统生成的（其中包括 Jetpack Compose 生成的帧），基准测试就会收集性能指标。

注意：访问界面对象时，请指定 packageName，因为此类测试是在单独的进程中运行。

进入应用的内部板块

有时，您需要对应用中无法直接从外部访问的板块进行基准测试。例如，您可能需要访问内部 activity（标有 exported=false）、进入 Fragment，或者滑开界面的某个部分。基准测试需要像用户一样手动进入应用的这些板块。

如需手动进入相应板块，请更改 setupBlock{} 内的代码以包含所需的效果，例如按钮点按或滑动。您的 measureBlock{} 仅包含您要实际进行基准测试的界面操作：

Kotlin

@Test
fun nonExportedActivityScrollList() {
    benchmarkRule.measureRepeated(
        // ...
        setupBlock = setupBenchmark()
    ) {
        // ...
    }
}

private fun setupBenchmark(): MacrobenchmarkScope.() -> Unit = {
    // Before starting to measure, navigate to the UI to be measured
    startActivityAndWait()

    // click a button to launch the target activity.
    // While we use button text  here to find the button, you could also use
    // accessibility info or resourceId.
    val selector = By.text("RecyclerView")
    if (!device.wait(Until.hasObject(selector), 5_500)) {
        fail("Could not find resource in time")
    }
    val launchRecyclerActivity = device.findObject(selector)
    launchRecyclerActivity.click()

    // wait until the activity is shown
    device.wait(
        Until.hasObject(By.clazz("$packageName.NonExportedRecyclerActivity")),
        TimeUnit.SECONDS.toMillis(10)
    )
}
NonExportedActivityBenchmark.kt

Java

@Test
public void scrollList() {
    benchmarkRule.measureRepeated(
        // ...
        /* setupBlock */ scope -> {
            // Before measuring, navigate to the default activity.
            scope.startActivityAndWait();

            // Click a button to launch the target activity.
            // While you use resourceId here to find the button, you can also
            // use accessibility info or button text content.
            UiObject2 launchRecyclerActivity = scope.getDevice().findObject(
                By.res(packageName, "launchRecyclerActivity")
            )
            launchRecyclerActivity.click();

            // Wait until activity is shown.
            scope.getDevice().wait(
                Until.hasObject(By.clazz("$packageName.NonExportedRecyclerActivity")),
                10000L
            )

            return Unit.INSTANCE;
        },
        /* measureBlock */ scope -> {
            // ...
        }
    );
}