我明确地为我的 LinearLayout 的背景定义了黑色（在我的 XML 中使用 @android:color/black），但有时（通常在屏幕旋转之后），黑色变成灰色（或透明黑色）。
这个问题出现在许多设备上：模拟器、Acer Liquid (Android 2.2) 和 Galaxy Nexus (Android 4.1)。
这是我的 XML 和活动代码：
XML:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="150dp"
android:minHeight="150dp">
<ImageView
android:id="@+id/projectview_description_image"
android:layout_width="match_parent"
android:layout_height="150dp"
android:contentDescription="@string/projectview_description_image_description"
android:scaleType="centerCrop"
android:src="@drawable/project_nophoto" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:orientation="vertical"
android:id="@+id/projectview_description_overlay"
android:paddingTop="5dp"
android:paddingLeft="10dp"
android:paddingBottom="5dp"
android:background="@android:color/black"
android:height="35dp">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/projectview_description_title"
android:textAllCaps="true"
android:textColor="@android:color/white"
android:textSize="20dp"
android:textStyle="bold"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/projectview_description_baseline"
android:textColor="@android:color/white"
android:textStyle="italic" />
</LinearLayout>
</RelativeLayout>
<!-- This LinearLayout background is buggy -->
<LinearLayout
android:layout_width="match_parent"
android:layout_height="40dp"
android:orientation="horizontal"
android:background="@android:color/black">
<ImageView
android:layout_width="175dp"
android:layout_height="25dp"
android:layout_gravity="center_vertical"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:scaleType="fitCenter"
android:src="@drawable/project_status_finish" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:gravity="right"
android:paddingRight="10dp"
android:text="@string/projectview_description_website"
android:textColor="@color/website_link"
android:textSize="15dp"
android:id="@+id/projectview_description_website" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:id="@+id/projectview_description_about_container"
android:padding="10dp"
android:paddingBottom="0dp">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/projectview_description_about"
android:textAllCaps="true"
android:textStyle="bold" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/projectview_description_about_text" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:id="@+id/projectview_description_questions_container" />
</LinearLayout>
</ScrollView>
活动：
public class ProjectViewActivity extends Activity implements OnClickListener {
private boolean displayMenu = false;
private Intent shareIntent;
private FavoriteSqlite db;
private I4pProjectTranslation project;
@TargetApi(14)
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
if(displayMenu) {
// Inflate menu only if it hasn't been done before
if(menu.size() == 0) {
// Inflating the menu
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.projectview, menu);
// Creating share intent
Intent prepareShareIntent = new Intent(Intent.ACTION_SEND);
prepareShareIntent.putExtra(Intent.EXTRA_TEXT, UriHelper.getProjectUrl(project));
prepareShareIntent.putExtra(Intent.EXTRA_SUBJECT, project.getTitle());
prepareShareIntent.setType("text/plain");
shareIntent = Intent.createChooser(prepareShareIntent, getResources().getText(R.string.projectview_menu_share_dialog));
}
// Defining favorite state
MenuItem favoriteItem = menu.getItem(0);
if(db.isFavorite(project))
favoriteItem.setTitle(R.string.projectview_menu_favorites_remove);
else
favoriteItem.setTitle(R.string.projectview_menu_favorites_add);
}
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch(item.getItemId()) {
case android.R.id.home:
if(getIntent().getData() != null) {
Intent intent = new Intent(this, HomepageActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
} else
finish();
break;
case R.id.projectview_favorite:
Toast t;
if(db.isFavorite(project)) {
db.removeFavorite(project);
t = Toast.makeText(this, getResources().getString(R.string.projectview_toast_favorites_remove, project.getTitle()), Toast.LENGTH_SHORT);
} else {
db.addFavorite(project);
t = Toast.makeText(this, getResources().getString(R.string.projectview_toast_favorites_add, project.getTitle()), Toast.LENGTH_SHORT);
}
t.show();
break;
case R.id.projectview_share:
startActivity(shareIntent);
break;
}
return super.onOptionsItemSelected(item);
}
@TargetApi(11)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(Build.VERSION.SDK_INT < 11)
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.loading);
db = new FavoriteSqlite(this);
if(Build.VERSION.SDK_INT >= 11)
getActionBar().setDisplayHomeAsUpEnabled(true);
project = (I4pProjectTranslation) getLastNonConfigurationInstance();
if(project != null)
displayProject();
else {
String projectLang;
String projectSlug;
Uri data = getIntent().getData();
if(data != null) {
List<String> path = data.getPathSegments();
projectLang = path.get(0);
projectSlug = path.get(2);
} else {
Bundle extras = getIntent().getExtras();
if(extras.containsKey("project_title"))
setTitle(extras.getString("project_title"));
projectLang = extras.getString("project_lang");
projectSlug = extras.getString("project_slug");
}
ProjectViewHandler handler = new ProjectViewHandler(this);
ProjectViewThread thread = new ProjectViewThread(handler, projectLang, projectSlug);
thread.start();
}
}
@Override
public Object onRetainNonConfigurationInstance() {
return project;
}
public void setProject(I4pProjectTranslation p) {
project = p;
}
@TargetApi(11)
public void displayProject() {
setContentView(R.layout.projectview_description);
displayMenu = true;
if(Build.VERSION.SDK_INT >= 11)
invalidateOptionsMenu(); // Rebuild the menu
setTitle(project.getTitle());
LinearLayout overlay = (LinearLayout) findViewById(R.id.projectview_description_overlay);
overlay.getBackground().setAlpha(127);
if(project.getProject().getPictures().size() > 0) {
ImageView image = (ImageView) findViewById(R.id.projectview_description_image);
image.setImageBitmap(project.getProject().getPictures().get(0).getImageBitmap());
}
TextView title = (TextView) findViewById(R.id.projectview_description_title);
title.setText(project.getTitle());
TextView baseline = (TextView) findViewById(R.id.projectview_description_baseline);
baseline.setText(project.getBaseline());
TextView website = (TextView) findViewById(R.id.projectview_description_website);
if("".equals(project.getProject().getWebsite()))
website.setVisibility(View.GONE);
else
website.setOnClickListener(this);
if("".equals(project.getAboutSection())) {
LinearLayout aboutContainer = (LinearLayout) findViewById(R.id.projectview_description_about_container);
aboutContainer.setVisibility(View.GONE);
} else {
TextView aboutText = (TextView) findViewById(R.id.projectview_description_about_text);
aboutText.setText(project.getAboutSection());
}
LinearLayout questions = (LinearLayout) findViewById(R.id.projectview_description_questions_container);
for(Question question : project.getProject().getQuestions()) {
if(question.getAnswer() != null) {
LinearLayout questionLayout = (LinearLayout) getLayoutInflater().inflate(R.layout.projectview_question, null);
TextView questionView = (TextView) questionLayout.findViewById(R.id.projectview_question_question);
TextView answerView = (TextView) questionLayout.findViewById(R.id.projectview_question_answer);
questionView.setText(question.getQuestion());
answerView.setText(question.getAnswer().trim());
questions.addView(questionLayout);
}
}
}
public void onClick(View arg0) {
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(project.getProject().getWebsite()));
startActivity(intent);
}
}
感谢帮助！