考虑下面的代码,它会保存静态变量:mMyArray in onSaveInstanceState并将其恢复到onRestoreInstanceState中,但是我发现它根本无法保存int数组。我试过基本类型值(int),它可以保存/恢复基本类型值。静态变量不能保存在onSaveInstanceState中?
public class StaticVarActivity extends Activity {
private static final String TAG = "StaticVarActivity";
private static int[] mMyArray = { 1, 1 };
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Log.d(TAG, "Setting values to 2 in onCreate");
mMyArray[0] = 2;
mMyArray[1] = 2;
findViewById(R.id.btn).setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Log.d(TAG, "Setting values to 3 in onClick");
mMyArray[0] = 3;
mMyArray[1] = 3;
}
});
}
/* (non-Javadoc)
* @see android.app.Activity#onRestoreInstanceState(android.os.Bundle)
*/
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
Log.d(TAG,"onRestoreInstanceState 1:"+mMyArray[0]+","+mMyArray[1]);
mMyArray = savedInstanceState.getIntArray("key");
Log.d(TAG,"onRestoreInstanceState 2:"+mMyArray[0]+","+mMyArray[1]);
}
/* (non-Javadoc)
* @see android.app.Activity#onSaveInstanceState(android.os.Bundle)
*/
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
Log.d(TAG,"onSaveInstanceState 1:"+mMyArray[0]+","+mMyArray[1]);
//int[] sss = new int[]{mMyArray[0],mMyArray[1]};
//outState.putIntArray("key", sss);
outState.putIntArray("key", mMyArray);
Log.d(TAG,"onSaveInstanceState 2:"+mMyArray[0]+","+mMyArray[1]);
}
}
日志:
04-14 15:16:00.633:DEBUG/StaticVarActivity(7251):在的onCreate 设定值至2 04-14 15:16:19.843:DEBUG/StaticVarActivity(7251):1:的onClick
//使配置改变,例如改变取向
04-14 15设定值至3 6:23.893:DEBUG/StaticVarActivity(7251):onSaveInstanceState 1:3,3 04-14 15:16:23.893:DEBUG/StaticVarActivity(7251):onSaveInstanceState 2:3,3 04-14 15:16:24.073: DEBUG/StaticVarActivity(7251):在onCreate中将值设置为2 04-14 15:16:24.073:DEBUG/StaticVarActivity(7251):onRestoreInstanceState 1:2,2 04-14 15:16:24.073:DEBUG/StaticVarActivity 7251):onRestoreInstanceState 2:2,2
如果我更改为:
private int[] mMyArray = { 1, 1 };
日志将是:
04-14 15:18:29.183:DEBUG/StaticVarActivity(7355):在的onCreate 设定值至2 04-14 15:18:32.123:DEBUG/StaticVarActivity(7355):设置值至3在的onClick
//使配置改变,例如改变取向
04-14 15:18:33.353:DEBUG/StaticVarActivity(7355):1的onSaveInstanceState:3,3 04-14 15时十八:33.353:DEBUG/StaticVarActivity(7355):onSaveInstanceState 2:3,3 04-14 15:18:33.373:DEBUG/StaticVarActi (7355):将值设置为onCreate 04-14 15:18:33.393:DEBUG/StaticVarActivity(7355):onRestoreInstanceState 1:2,2 04-14 15:18:33.393:DEBUG/StaticVarActivity(7355) :onRestoreInstanceState 2:3,3
我才知道它并不需要保存静态变量,但为什么出现这种情况?