作为测试示例,有一个具有 2 个活动的应用程序:
MainActivity
,单击按钮时启动 SecondActivity
。系统设置中的自动旋转已关闭(或打开 - 没关系,“后面”选项无论如何都会被忽略)。
android:screenOrientation="landscape"
设置为 MainActivity
,android:screenOrientation="behind"
设置为 SecondActivity
,这意味着 SecondActivity
也必须以横向启动。SecondActivity
从纵向开始。
AndroidManifest.xml:
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="16" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.my.example.testbehindorientation.MainActivity"
android:label="@string/app_name"
android:screenOrientation="landscape" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.my.example.testbehindorientation.SecondActivity"
android:configChanges="screenSize|orientation"
android:label="@string/title_activity_second"
android:screenOrientation="behind" >
</activity>
</application>
SecondActivity.java:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
logOrientation("onCreate");
}
@Override
protected void onDestroy() {
super.onDestroy();
logOrientation("onDestroy");
}
@Override
protected void onResume() {
super.onResume();
logOrientation("onResume");
}
private void logOrientation(String prefix) {
int requestedOrientation = this.getRequestedOrientation();
WindowManager lWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
Configuration cfg = getResources().getConfiguration();
int lRotation = lWindowManager.getDefaultDisplay().getRotation();
int orientation = cfg.orientation;
Log.i(LOG_TAG, prefix + ", requestedOrientation is " + requestedOrientation + ", rotation is " + lRotation + ", orientation is " + orientation);
}
在
android:configChanges="screenSize|orientation"
中单击按钮后,AndroidManifest.xml
中没有 SecondActivity
行的日志输出:MainActivity
使用
onCreate, requestedOrientation is 3, rotation is 1, orientation is 2
onResume, requestedOrientation is 3, rotation is 1, orientation is 2
onDestroy, requestedOrientation is 3, rotation is 0, orientation is 1
onCreate, requestedOrientation is 3, rotation is 0, orientation is 1
onResume, requestedOrientation is 3, rotation is 0, orientation is 1
行记录在
android:configChanges="screenSize|orientation"
中:AndroidManifest.xml
现在没有活动娱乐,但结果总是一样的 -
onCreate, requestedOrientation is 3, rotation is 1, orientation is 2
onResume, requestedOrientation is 3, rotation is 1, orientation is 2
是从纵向开始! :( 也就是说,由于某种原因,
SecondActivity
在onResume之后旋转为纵向。
为什么?.测试于:
配备 Android 4.0.4 的三星 Galaxy S3(好的)
SecondActivity
在清单文件中删除此语句,因为 SDKVersion=16 仅适用于 v4.0。
Manifest.xml
android:targetSdkVersion="16"
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="16" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.my.example.testbehindorientation.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.my.example.testbehindorientation.SecondActivity"
android:configChanges="screenSize|orientation"
android:label="@string/title_activity_second" >
</activity>
</application>
onCreate()方法中添加以下代码
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);//Change according to need this is for landscape
logOrientation("onCreate");
}
@Override
protected void onDestroy() {
super.onDestroy();
logOrientation("onDestroy");
}
@Override
protected void onResume() {
super.onResume();
logOrientation("onResume");
}
private void logOrientation(String prefix) {
int requestedOrientation = this.getRequestedOrientation();
WindowManager lWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
Configuration cfg = getResources().getConfiguration();
int lRotation = lWindowManager.getDefaultDisplay().getRotation();
int orientation = cfg.orientation;
Log.i(LOG_TAG, prefix + ", requestedOrientation is " + requestedOrientation + ", rotation is " + lRotation + ", orientation is " + orientation);
}