【问题标题】：ActivityInstrumentationTestCase2 issues - test hangs because of invalidate() call in the code I'm writing a test forActivityInstrumentationTestCase2 问题 - 由于我正在为其编写测试的代码中的 invalidate() 调用，测试挂起
【发布时间】：2011-11-02 08:51:36
【问题描述】：

我正在对我编写的一些代码进行测试提炼成下面粘贴的示例项目。我遇到的问题是测试挂起测试运行器并且我的测试用例中没有一个测试运行。

我已将问题归结为对 invalidate() 的调用 getChildStaticTransformation(View child, Transformation t) 我是覆盖做一些缩放效果。

如果我注释掉对 invalidate() 的调用，那么测试就会运行。这我之所以调用 invalidate() 是为了确保视图得到应用缩放效果后重绘。

如果我不调用 invalidate() 那么视图看起来不正确，直到用户操作会强制重新绘制屏幕。

两个问题：

为什么 invalidate() 会阻止测试运行？
我是否应该以不同的方式缩放视图？需要调用 invalidate() 吗？

以下是 Eclipse Android 控制台的输出，显示了在哪里测试挂起：

[2011-08-19 13:51:27 - HelloGalleryTest]
------------------------------
[2011-08-19 13:51:27 - HelloGalleryTest] Android Launch!
[2011-08-19 13:51:27 - HelloGalleryTest] adb is running normally.
[2011-08-19 13:51:27 - HelloGalleryTest] Performing
android.test.InstrumentationTestRunner JUnit launch
[2011-08-19 13:51:27 - HelloGalleryTest] Automatic Target Mode: using
device '428024642BF9457'
[2011-08-19 13:51:27 - HelloGalleryTest] Uploading
HelloGalleryTest.apk onto device '428024642BF9457'
[2011-08-19 13:51:27 - HelloGalleryTest] Installing
HelloGalleryTest.apk...
[2011-08-19 13:51:29 - HelloGalleryTest] Success!
[2011-08-19 13:51:29 - HelloGalleryTest] Project dependency found,
installing: HelloGallery
[2011-08-19 13:51:29 - HelloGallery] Uploading HelloGallery.apk onto
device '428024642BF9457'
[2011-08-19 13:51:29 - HelloGallery] Installing HelloGallery.apk...
[2011-08-19 13:51:31 - HelloGallery] Success!
[2011-08-19 13:51:31 - HelloGalleryTest] Launching instrumentation
android.test.InstrumentationTestRunner on device 428024642BF9457
[2011-08-19 13:51:31 - HelloGalleryTest] Collecting test information
[2011-08-19 13:51:32 - HelloGalleryTest] Sending test information to
Eclipse
[2011-08-19 13:51:32 - HelloGalleryTest] Running tests...

以下是我编写的示例项目代码和测试用例表现出我上面描述的问题。 HelloGallery.getChildStaticTransformation（查看孩子，转换 t) 是调用 invalidate() 的方法。

下面包含的其他文件是为了完整性，以防您想要尝试构建项目并观察我所描述的行为。

START::HELLO_GALLERY_PROJECT-FILES

HelloGallery.java

package com.hello;

import android.content.Context;
import android.graphics.Camera;
import android.graphics.Matrix;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.Transformation;
import android.widget.Gallery;

public class HelloGallery extends Gallery {

       private Camera mCamera = new Camera();

       /**
        * The position (index) of the centered view in the gallery.
        */
       public int mCenterViewPositionIndex;

       public HelloGallery(Context context, AttributeSet attrs) {
               super(context, attrs);
               this.setStaticTransformationsEnabled(true);
       }

       /**
        * {@inheritDoc}
        *
        * @see #setStaticTransformationsEnabled(boolean)
        */
       protected boolean getChildStaticTransformation(View child,
Transformation t) {
               t.clear();

               mCamera.save();
               final Matrix imageMatrix = t.getMatrix();
               int position = getPositionForView(child);
               t.setTransformationType(Transformation.TYPE_MATRIX);

               if (child == getSelectedView()) {
                       mCenterViewPositionIndex = position;

                       t.setAlpha(1f);
                       mCamera.translate(-20, 20, -200);
               }
               else if(((mCenterViewPositionIndex - 1) == position )) {
                       t.setAlpha(0.5f);
                       // no need to zoom this view.
               }
               else if((mCenterViewPositionIndex + 1) == position ) {
                       t.setAlpha(0.5f);
                       // no need to zoom this view.
               }

               else if(((mCenterViewPositionIndex - 2) == position )) {
                       t.setAlpha(0.35f);
                       mCamera.translate(0, 0, 250);
               }
               else if((mCenterViewPositionIndex + 2) == position ) {
                       t.setAlpha(0.35f);
                       mCamera.translate(0, 0, 250);
               }

               else if(((mCenterViewPositionIndex - 3) == position )) {
                       t.setAlpha(0.1f);
                       mCamera.translate(0, 0, 350);
               }
               else if((mCenterViewPositionIndex + 3) == position ) {
                       t.setAlpha(0.2f);
                       mCamera.translate(0, 0, 350);
               }else {
                       t.setAlpha(0.1f);
                       mCamera.translate(0, 0, 450);
               }

               mCamera.getMatrix(imageMatrix);
               mCamera.restore();
//              invalidate();  //  <----  commenting out this line allows the Test
to run.   Uncommenting this line will not allow the Test to run.

               return true;
       }
}

HelloGalleryActivity.java

package com.hello;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Gallery;

public class HelloGalleryActivity extends Activity implements OnItemClickListener {
    private Gallery mGallery;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mGallery=(Gallery)findViewById(R.id.gallery);

        //String array holding the values
        String [] text=new String[]{"Hello","Hi","Alloha","Bonjour","Hallo","¡Hola"};

        //Circular Array adapter to display our values in the gallery control
        HomeGalleryAdapter adapter = new HomeGalleryAdapter(this, R.layout.gallery_item_layout, text);
        mGallery.setAdapter(adapter);
        mGallery.setSelection(adapter.MIDDLE);
        mGallery.setOnItemClickListener(this);
        mGallery.setOnTouchListener(new OnTouchListener() {

            public boolean onTouch(View arg0, MotionEvent arg1) {
                Log.d("HelloGalleryActivity", " --> onTouch");
                return false;
            }
        });        
    }

    @Override
    public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
        Log.d("HelloGalleryActivity", " --> onItemClick");  
    }
}

HelloGalleryAdapter.java

package com.hello;

import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class HomeGalleryAdapter extends ArrayAdapter<String> {
       private LayoutInflater mLayoutInflater;
       private TextView mText;
       private int mLayoutId;

       public static final int HALF_MAX_VALUE = Integer.MAX_VALUE/2;
   public final int MIDDLE;
   private String[] mObjects;

       public HomeGalleryAdapter(Context context, int layoutId, String[]
lables) {
               super(context, 0, lables);

               mLayoutInflater = ((Activity) context).getLayoutInflater();
               mLayoutId = layoutId;

           mObjects = lables;
           MIDDLE = HALF_MAX_VALUE - HALF_MAX_VALUE % lables.length;
       }

       public int getCount() {
               return Integer.MAX_VALUE;
       }

       public String getItem(int position) {
               return mObjects[position % mObjects.length];
       }

       public long getItemId(int position) {
               return position % mObjects.length;
       }

       public View getView(int position, View convertView, ViewGroup group)
{
               if (convertView == null) {
                       convertView = mLayoutInflater.inflate(mLayoutId, group, false);
               }

               mText = (TextView) convertView.findViewById(R.id.gallery_item_text);

               mText.setText((String) getItem(position));
               mText.setTextColor(Color.WHITE);

               convertView.setTag(mText.getText());

               return convertView;
       }
}

res/layout/main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
       xmlns:android="http://schemas.android.com/apk/res/android"
       android:orientation="vertical"
       android:layout_width="fill_parent"
       android:layout_height="fill_parent">

       <TextView
               android:id="@+id/textview"
               android:layout_width="fill_parent"
               android:layout_height="wrap_content"
               android:text="@string/hello" />

       <com.hello.HelloGallery
               android:id="@+id/gallery"
               android:layout_gravity="center"
               android:spacing="0dp"
               android:layout_width="fill_parent"
               android:layout_height="fill_parent" />
</LinearLayout>

res/layout/gallery_item_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
       xmlns:android="http://schemas.android.com/apk/res/android"
       android:id="@+id/home_gallery_item_layout"
       android:orientation="vertical"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_gravity="center">

       <RelativeLayout
               android:id="@+id/gallery_item_background"
               android:layout_width="100dip"
               android:layout_height="100dip"
               android:orientation="horizontal"
               android:background="@drawable/gallery_item_selector">

               <ImageView
                       android:src="@drawable/icon"
                       android:id="@+id/gallery_item_icon"
                       android:layout_width="wrap_content"
                       android:layout_height="wrap_content"
                       android:layout_centerInParent="true" />

       </RelativeLayout>

       <TextView
               android:id="@+id/gallery_item_text"
               android:layout_width="wrap_content"
               android:layout_height="wrap_content"
               android:layout_gravity="center"
               android:textSize="20sp" />
</LinearLayout>

res/drawable/gallery_item_selector.xml

 <selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true"
          android:drawable="@drawable/background_selected" /> <!--
pressed -->
    <item android:drawable="@drawable/background_normal" /> <!--
default -->
 </selector>

res/drawable/background_normal.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
   android:shape="rectangle">
   <gradient
       android:startColor="#80000000"
       android:endColor="#80FFFFFF"
       android:angle="45"/>
   <padding android:left="7dp"
       android:top="7dp"
       android:right="7dp"
       android:bottom="7dp" />
   <corners android:radius="8dp" />
</shape>

res/drawable/background_selected.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
   android:shape="rectangle">
   <gradient
       android:startColor="#80000000"
       android:endColor="#807EB6FF"
       android:angle="45"/>
   <padding android:left="7dp"
       android:top="7dp"
       android:right="7dp"
       android:bottom="7dp" />
   <corners android:radius="8dp" />
</shape>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest
       xmlns:android="http://schemas.android.com/apk/res/android"
       package="com.hello"
       android:versionCode="1"
       android:versionName="1.0">
       <uses-sdk
               android:minSdkVersion="7" />

       <application
               android:icon="@drawable/icon"
               android:label="@string/app_name">
               <activity
                       android:name=".HelloGalleryActivity"
                       android:label="@string/app_name">
                       <intent-filter>
                               <action
                                       android:name="android.intent.action.MAIN" />
                               <category
                                       android:name="android.intent.category.LAUNCHER" />
                       </intent-filter>
               </activity>

       </application>
</manifest>

END::HELLO_GALLERY_PROJECT-FILES

START::HELLO_GALLERY_TEST_PROJECT-FILES

HelloGalleryActivityTest.java (

package com.hello.test;

import android.test.ActivityInstrumentationTestCase2;
import android.widget.Gallery;
import android.widget.SpinnerAdapter;

import com.hello.HelloGalleryActivity;

public class HelloGalleryActivityTest extends
ActivityInstrumentationTestCase2<HelloGalleryActivity> {
       private HelloGalleryActivity mActivity; // the activity under test
       private Gallery mGallery;
       private String[] mGalleryDataTestArray;
       private SpinnerAdapter mGalleryData;

       public HelloGalleryActivityTest() {
               super("com.hello", HelloGalleryActivity.class);
               mGalleryDataTestArray = new String[] { "Hello", "Hi", "Alloha",
"Bonjour", "Hallo", "¡Hola" };
       }

       @Override
       protected void setUp() throws Exception {
               super.setUp();
               setActivityInitialTouchMode(false);

               mActivity = this.getActivity();
               mGallery = (Gallery) mActivity.findViewById(com.hello.R.id.gallery);
               mGalleryData = (SpinnerAdapter) mGallery.getAdapter();
       }

       public void testPreconditions() {
               assertNotNull(mActivity);
               assertNotNull(mGallery);
               assertNotNull(mGallery.getOnItemClickListener());
               assertNotNull(mGalleryData);
       }

       public void testInitialGalleryPosition() {
               int position = mGallery.getSelectedItemPosition();
               String galleryItemLabel = (String)
mGallery.getItemAtPosition(position);

               assertEquals(mGalleryDataTestArray[0], galleryItemLabel);
       }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.hello.test"
     android:versionCode="1"
     android:versionName="1.0">
   <uses-sdk android:minSdkVersion="12" />
   <instrumentation android:targetPackage="com.hello"
android:name="android.test.InstrumentationTestRunner" />
   <application android:icon="@drawable/icon" android:label="@string/
app_name">

   <uses-library android:name="android.test.runner" />
   </application>
</manifest>

END::HELLO_GALLERY_TEST_PROJECT-FILE

【问题讨论】：

标签： java android testing junit instrumentation

【解决方案1】：

尝试使用 postInvalidate() 而不是 invalidate()。

我不能 100% 确定发生了什么，但我怀疑您的代码中有一些东西阻塞了 UI 线程。使用 postInvalidate() 将立即返回并让您的代码完成，这将解除对 UI 线程的阻塞。

【讨论】：

感谢您的建议，虽然它没有解决问题。 postInvalidate() 和 invalidate() 表现出完全相同的行为。

【解决方案2】：

问题解决了！

不需要 invalidate 调用.. 它搞砸了 PERIOD！

诀窍是向 HelloGallery.java 添加一个方法来设置中心位置并在超类上调用 setPosition。

HelloGallery.java

public void setSelectionToCenter(int position) {
    mCenterViewPositionIndex = position;
    setSelection(mCenterViewPositionIndex);
}

然后在 HelloGalleryActivity 中调用 setSelectionToCenter 方法而不是 setSelection。

HelloGalleryActivity

public void onCreate(Bundle savedInstanceState) {
    ...
    ((HelloGallery)mGallery).setSelectionToCenter(adapter.MIDDLE);
    ...
}

测试现在运行起来就像一个魅力！哇！
感谢神秘开发者 Betsy 帮我追踪了这个问题！

【讨论】：