android - Android 视图性能 - 在两个视图之间切换

Question

性能问题 - 如果我有两个相互排斥的视图（例如成功通知/失败通知） - 从性能角度来看，最好使用：

1）parentView.removeView(indexOfChild)和addView()两者之间的过渡

2）覆盖两个视图并切换它们的可见性

3) 使用ViewSwitcher

Answer 1

我进行了一项小型研究以找出答案。简而言之 - 改变可见性会更好。

结果是（以毫秒为单位，平均估计）：

HTC Desire (4.0.4)
TEST1(visibility) = 251.5
TEST2(movement) = 751.1
TEST3(ViewSwitcher) = 267.0


HTC Wildfire (2.3.5)
TEST1(visibility) = 285.0
TEST2(movement) = 172.7
TEST3(ViewSwitcher) = 302.1


Samsung GALAXY S3 (4.1.2)
TEST1(visibility) = 83.5
TEST2(movement) = 3364.9
TEST3(ViewSwitcher) = 108.7


Google Nexus 4 (4.3)
TEST1(visibility) = 101.7
TEST2(movement) = 380.7
TEST3(ViewSwitcher) = 126.9

测试代码：

public class MainActivity extends Activity {

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

        test2View1 = findViewById(R.id.move_test1);
        test2View2 = findViewById(R.id.move_test2);

        findViewById(R.id.button1_start).setOnClickListener(
                new OnClickListener() {

                    @Override
                    public void onClick(View v) {
                        final int totalExpCount = 10;
                        final double[] totalResult = new double[3];
                        for (int i = 0; i < totalExpCount; i++) {
                            final long[] currentResult = performanceTest();
                            for (int j = 0; j < 3; j++) {
                                totalResult[j] += currentResult[j];
                            }
                        }

                        for (int j = 0; j < 3; j++) {
                            totalResult[j] /= totalExpCount;
                        }

                        Log.i("TIMING",
                                "=========================================");
                        Log.i("TIMING", "TOTAL - TEST1(visibility) = "
                                + totalResult[0]);
                        Log.i("TIMING", "TOTAL - TEST2(movement) = "
                                + totalResult[1]);
                        Log.i("TIMING", "TOTAL - TEST3(ViewSwitcher) = "
                                + totalResult[2]);
                    }
                });

    }

    View test2View1;
    View test2View2;

    private final long[] performanceTest() {
        final int testCount = 10000;

        // test 1
        final View test1View1 = findViewById(R.id.visibility_test1);
        final View test1View2 = findViewById(R.id.visibility_test2);

        final long test1StartTime = System.currentTimeMillis();
        for (int i = 0; i < testCount; i++) {
            final int visibility = test1View1.getVisibility();
            test1View1.setVisibility(test1View2.getVisibility());
            test1View2.setVisibility(visibility);
        }
        final long test1EndTime = System.currentTimeMillis();
        final long test1ResultTime = test1EndTime - test1StartTime;

        // test 2
        final ViewGroup test2ParentView = (ViewGroup) findViewById(R.id.layout_test2);

        test2ParentView.removeAllViews();
        test2ParentView.addView(test2View1);

        final long test2StartTime = System.currentTimeMillis();
        for (int i = 0; i < testCount; i++) {
            if ((i % 2) == 0) {
                test2ParentView.addView(test2View2);
                test2ParentView.removeView(test2View1);
            } else {
                test2ParentView.addView(test2View1);
                test2ParentView.removeView(test2View2);
            }
        }
        final long test2EndTime = System.currentTimeMillis();
        final long test2ResultTime = test2EndTime - test2StartTime;

        // test 3
        final ViewSwitcher test3ParentView = (ViewSwitcher) findViewById(R.id.layout_test3);
        test3ParentView.reset();

        final long test3StartTime = System.currentTimeMillis();
        for (int i = 0; i < testCount; i++) {
            test3ParentView.showNext();
        }
        final long test3EndTime = System.currentTimeMillis();
        final long test3ResultTime = test3EndTime - test3StartTime;

        Log.i("TIMING", "-----------------------------------------");
        Log.i("TIMING", "TEST1(visibility) = " + test1ResultTime);
        Log.i("TIMING", "TEST2(movement) = " + test2ResultTime);
        Log.i("TIMING", "TEST3(ViewSwitcher) = " + test3ResultTime);

        final long[] result = new long[3];
        result[0] = test1ResultTime;
        result[1] = test2ResultTime;
        result[2] = test3ResultTime;
        return result;

    }
}

和 XML：

<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:orientation="vertical"
    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=".MainActivity" >

    <Button
        android:id="@+id/button1_start"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Start test" />

   <RelativeLayout
        android:id="@+id/layout_test1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <TextView
            android:id="@+id/visibility_test1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="one" />

        <TextView
            android:id="@+id/visibility_test2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="two"
            android:visibility="gone" />
    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/layout_test2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <TextView
            android:id="@+id/move_test1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="one" />

        <TextView
            android:id="@+id/move_test2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="two" />
    </RelativeLayout>

    <ViewSwitcher
        android:id="@+id/layout_test3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >


        <TextView
            android:id="@+id/switcher_test1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="one" />

        <TextView
            android:id="@+id/switcher_test2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="two" />
    </ViewSwitcher>

</LinearLayout>