Java 其中是在onCreate(Bundle savedInstanceState)中创建的Bundle对象

Java 其中是在onCreate(Bundle savedInstanceState)中创建的Bundle对象,java,android,android-activity,oncreate,Java,Android,Android Activity,Oncreate,在Android中,onCreate方法将savedInstanceState作为Bundle对象的引用。 我只想知道在哪里以及如何创建Bundle对象?如果您将应用程序的状态保存在Bundle中(通常是onSaveInstanceState中的非持久性动态数据),那么如果需要重新创建活动(例如,方向更改),它可以传递回onCreate,这样您就不会丢失以前的信息。如果未提供数据,则savedInstanceState为空 您需要重写onSaveInstanceState(Bundle save

在Android中,
onCreate
方法将
savedInstanceState
作为Bundle对象的引用。
我只想知道在哪里以及如何创建
Bundle
对象?

如果您将应用程序的状态保存在Bundle中(通常是onSaveInstanceState中的非持久性动态数据),那么如果需要重新创建活动(例如,方向更改),它可以传递回onCreate,这样您就不会丢失以前的信息。如果未提供数据,则savedInstanceState为空

您需要重写onSaveInstanceState(Bundle savedInstanceState),并将要更改的应用程序状态值写入Bundle参数,如下所示:

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
  super.onSaveInstanceState(savedInstanceState);
  // Save UI state changes to the savedInstanceState.
  // This bundle will be passed to onCreate if the process is
  // killed and restarted.
  savedInstanceState.putBoolean("MyBoolean", true);
  savedInstanceState.putDouble("myDouble", 1.9);
  savedInstanceState.putInt("MyInt", 1);
  savedInstanceState.putString("MyString", "Welcome back to Android");
  // etc.
}
@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
  super.onRestoreInstanceState(savedInstanceState);
  // Restore UI state from the savedInstanceState.
  // This bundle has also been passed to onCreate.
  boolean myBoolean = savedInstanceState.getBoolean("MyBoolean");
  double myDouble = savedInstanceState.getDouble("myDouble");
  int myInt = savedInstanceState.getInt("MyInt");
  String myString = savedInstanceState.getString("MyString");
}
Bundle本质上是一种存储NVP(“名称-值对”)映射的方法,它将被传递到onCreate()和onRestoreInstanceState(),您可以在其中提取如下值:

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
  super.onSaveInstanceState(savedInstanceState);
  // Save UI state changes to the savedInstanceState.
  // This bundle will be passed to onCreate if the process is
  // killed and restarted.
  savedInstanceState.putBoolean("MyBoolean", true);
  savedInstanceState.putDouble("myDouble", 1.9);
  savedInstanceState.putInt("MyInt", 1);
  savedInstanceState.putString("MyString", "Welcome back to Android");
  // etc.
}
@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
  super.onRestoreInstanceState(savedInstanceState);
  // Restore UI state from the savedInstanceState.
  // This bundle has also been passed to onCreate.
  boolean myBoolean = savedInstanceState.getBoolean("MyBoolean");
  double myDouble = savedInstanceState.getDouble("myDouble");
  int myInt = savedInstanceState.getInt("MyInt");
  String myString = savedInstanceState.getString("MyString");
}

如果将应用程序的状态保存在捆绑包中(通常是onSaveInstanceState中的非持久性动态数据),如果需要重新创建活动(例如,方向更改),则可以将其传递回onCreate,以避免丢失此先前信息。如果未提供数据,则savedInstanceState为空

您需要重写onSaveInstanceState(Bundle savedInstanceState),并将要更改的应用程序状态值写入Bundle参数,如下所示:

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
  super.onSaveInstanceState(savedInstanceState);
  // Save UI state changes to the savedInstanceState.
  // This bundle will be passed to onCreate if the process is
  // killed and restarted.
  savedInstanceState.putBoolean("MyBoolean", true);
  savedInstanceState.putDouble("myDouble", 1.9);
  savedInstanceState.putInt("MyInt", 1);
  savedInstanceState.putString("MyString", "Welcome back to Android");
  // etc.
}
@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
  super.onRestoreInstanceState(savedInstanceState);
  // Restore UI state from the savedInstanceState.
  // This bundle has also been passed to onCreate.
  boolean myBoolean = savedInstanceState.getBoolean("MyBoolean");
  double myDouble = savedInstanceState.getDouble("myDouble");
  int myInt = savedInstanceState.getInt("MyInt");
  String myString = savedInstanceState.getString("MyString");
}
Bundle本质上是一种存储NVP(“名称-值对”)映射的方法,它将被传递到onCreate()和onRestoreInstanceState(),您可以在其中提取如下值:

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
  super.onSaveInstanceState(savedInstanceState);
  // Save UI state changes to the savedInstanceState.
  // This bundle will be passed to onCreate if the process is
  // killed and restarted.
  savedInstanceState.putBoolean("MyBoolean", true);
  savedInstanceState.putDouble("myDouble", 1.9);
  savedInstanceState.putInt("MyInt", 1);
  savedInstanceState.putString("MyString", "Welcome back to Android");
  // etc.
}
@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
  super.onRestoreInstanceState(savedInstanceState);
  // Restore UI state from the savedInstanceState.
  // This bundle has also been passed to onCreate.
  boolean myBoolean = savedInstanceState.getBoolean("MyBoolean");
  double myDouble = savedInstanceState.getDouble("myDouble");
  int myInt = savedInstanceState.getInt("MyInt");
  String myString = savedInstanceState.getString("MyString");
}

你能告诉我活动对象是在哪里创建的吗?你能告诉我活动对象是在哪里创建的吗