我有一些具有这种结构的片段:
<RelativeLayout
android:id="@+id/control_panel"
android:visibility="gone">
<RelativeLayout
android:id="@+id/control_panel_icon">
<ImageView
android:id="@+id/control_panel_icon_1"
android:src="@drawable/ic_control_panel_icon_1" />
<ImageView
android:id="@+id/control_panel_icon_2"
android:src="@drawable/ic_control_panel_icon_2"
android:visibility="gone"/>
</RelativeLayout>
<TextView
android:id="@+id/control_panel_tv"
android:text="@string/not_available" />
</RelativeLayout>
在Fragment类中,我有onSaveInstanceState
和onActivityCreated
:
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putString("tv", panel_tv.getText().toString());
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
if (savedInstanceState != null)
panel_tv.setText(savedInstanceState.getString("tv"));
}
因此它解决了保存TextView
状态的问题。
在Fragment类中,我还设置了要显示某些功能的图像:
public void setIcon(boolean condition){
if (condition) {
control_panel_icon_1.setVisibility(View.GONE);
control_panel_icon_2.setVisibility(View.VISIBLE);
} else {
control_panel_icon_1.setVisibility(View.VISIBLE);
control_panel_icon_2.setVisibility(View.GONE);
}
}
有什么方法可以保存和恢复当前显示的图像?
我知道,我不应该保存整个窗口小部件,但是如果我可以保存RelativeLayout
的状态,它将恢复所有子状态吗?
答案 0 :(得分:2)
在您的Fragment类中,声明一个私有变量:
private boolean condition; // rename to something more descriptive
现在setIcon()
中存储值:
this.condition = condition;
最后将其保存到onSaveInstanceState()
中的捆绑软件中:
outState.putBoolean("condition", this.condition);
并在onActivityCreated()
中阅读:
this.condition = savedInstanceState.getBoolean("condition");
this.setIcon(this.condition);
注意
您无需保存TextView
中的文本。对super.onSaveInstanceState()
的呼叫已经为您解决了这个问题。
答案 1 :(得分:2)
您可以将condition
保存在outState
中,如下所示:
outState.putBoolean("condition", condition);
然后阅读并更新图像视图
setIcon(savedInstanceState.getBoolean("condition"))
或者您可以通过putInt
方法保存图像视图的可见性状态:
outState.putInt("ic1", control_panel_icon_1.getVisibility());
outState.putInt("ic2", control_panel_icon_2.getVisibility());
然后恢复状态:
control_panel_icon_1.setVisibility(savedInstanceState.getInt("ic1"));
control_panel_icon_2.setVisibility(savedInstanceState.getInt("ic2"));