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无法使用LayoutManager还原RecyclerView中的滚动位置

linearlayoutmanager mvp android-recyclerview android java

hsm59 · 技术社区 · 7 年前

因此,我有一个EditText,我在其上设置了一个EditoractionListener,即在用户输入文本并按enter/search后,它将获取详细信息并相应地填充回收器视图。

现在为了保存配置更改的状态,我编写了以下代码-

Parcelable stateList;

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);

    //Saving instance of the state in Parcelable stateList
    stateList = recyclerView.getLayoutManager().onSaveInstanceState();
    outState.putParcelable(RETAIN_STATE, stateList);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);

    if(savedInstanceState!=null) {
        stateList = savedInstanceState.getParcelable(RETAIN_STATE);
        recyclerView.getLayoutManager().onRestoreInstanceState(stateList);
    }
}

我正在使用MVP,所以我正在演示者的回调中设置适配器。

在屏幕旋转后,当我们在键盘上单击enter/search时,我能够保持状态,所以我在onRestoreInstanceState()中尝试了这种黑客攻击,但我认为应该有更好的方法来实现这一点。

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);

    if(savedInstanceState!=null) {
        //The hack!
        et_search.onEditorAction(EditorInfo.IME_ACTION_SEARCH);
        stateList = savedInstanceState.getParcelable(RETAIN_STATE);
        recyclerView.getLayoutManager().onRestoreInstanceState(stateList);
    }
}

提前谢谢。

2 回复 | 直到 7 年前

akshay_shahane 7 年前

<activity android:name=".mainpage.view.MainActivity" android:configChanges="orientation|screenSize|screenLayout" >

将其包含在该活动的清单中

import android.content.Context;
import android.os.Bundle;
import android.os.Parcelable;
import android.support.annotation.Nullable;
import android.support.v7.widget.RecyclerView;
import android.util.AttributeSet;

/**
 * Class {@link StatefulRecyclerView} extends {@link RecyclerView} and adds position management on configuration changes.
 *
 * @author FrantisekGazo
 * @version 2016-03-15
 */
public final class StatefulRecyclerView
        extends RecyclerView {

    private static final String SAVED_SUPER_STATE = "super-state";
    private static final String SAVED_LAYOUT_MANAGER = "layout-manager-state";

    private Parcelable mLayoutManagerSavedState;

    public StatefulRecyclerView(Context context) {
        super(context);
    }

    public StatefulRecyclerView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public StatefulRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected Parcelable onSaveInstanceState() {
        Bundle bundle = new Bundle();
        bundle.putParcelable(SAVED_SUPER_STATE, super.onSaveInstanceState());
        bundle.putParcelable(SAVED_LAYOUT_MANAGER, this.getLayoutManager().onSaveInstanceState());
        return bundle;
    }

    @Override
    protected void onRestoreInstanceState(Parcelable state) {
        if (state instanceof Bundle) {
            Bundle bundle = (Bundle) state;
            mLayoutManagerSavedState = bundle.getParcelable(SAVED_LAYOUT_MANAGER);
            state = bundle.getParcelable(SAVED_SUPER_STATE);
        }
        super.onRestoreInstanceState(state);
    }

    /**
     * Restores scroll position after configuration change.
     * <p>
     * <b>NOTE:</b> Must be called after adapter has been set.
     */
    private void restorePosition() {
        if (mLayoutManagerSavedState != null) {
            this.getLayoutManager().onRestoreInstanceState(mLayoutManagerSavedState);
            mLayoutManagerSavedState = null;
        }
    }

    @Override
    public void setAdapter(Adapter adapter) {
        super.setAdapter(adapter);
        restorePosition();
    }
}

Link to gist

Ekalips 7 年前

onRestoreInstanceState LayoutManager中的配置更改,因为它将自动调用(所有视图都具有 onSaveInstanceState onRestoreInstanceState 这是从生命周期所有者那里传来的)。即使你想-你所要做的就是恢复视图的滚动位置。

RecyclerView 并在屏幕旋转时将其设置回原位。然后再次调用search(或filter,随便什么)。