可能,我的代码是正确的,但是旋转屏幕时方法onSaveInstanceState()不起作用。活动销毁(onDestroy()有效)后,数据不会保存。但是,该方法在方法onPause()和onStop()之后起作用。活动上有一个元素-textView,当方法工作时我会写文本。有错误吗?先感谢您。
public class MainActivity extends AppCompatActivity {
TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getSupportActionBar().hide();
textView = findViewById(R.id.textView);
if (savedInstanceState != null)
{
textView.setText(savedInstanceState.getString("saveInstance"));
}
Log.i("lifecycle show", "onCreate() worked");
textView.append("onCreate() worked\n");
}
@Override
protected void onStart() {
super.onStart();
Log.i("lifecycle show", "onStart() worked");
textView.append("onStart() worked\n");
}
@Override
protected void onResume() {
super.onResume();
Log.i("lifecycle show", "onResume() worked");
textView.append("onResume() worked\n");
}
@Override
protected void onRestart() {
super.onRestart();
Log.i("lifecycle show", "onRestart() worked");
textView.append("onRestart() worked\n");
}
@Override
protected void onPause() {
super.onPause();
Log.i("lifecycle show", "onPause() worked");
textView.append("onPause() worked\n");
}
@Override
protected void onStop() {
super.onStop();
Log.i("lifecycle show", "onStop() worked");
textView.append("onStop() worked\n");
}
@Override
protected void onDestroy() {
super.onDestroy();
Log.i("lifecycle show", "onDestroy() worked");
textView.append("onDestroy() worked\n");
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
Log.i("lifecycle show", "onSaveInstanceState() worked");
textView.append("onSaveInstanceState() worked\n");
outState.putString("savedInstance", textView.getText().toString());
}
}
标签错误。您使用“ savedInstance”作为标签放置字符串,然后通过标签“ saveInstance”获取字符串。
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