小编Car*_*ona的帖子

我在我的android项目中使用RecyclerView,其性能非常糟糕.从这里的答案,我尝试添加adapter.setHasStableIds(true);到我的代码.运行时,我收到一个错误:

java.lang.IllegalStateException: Cannot change whether this adapter has stable IDs while the adapter has registered observers.

我的完整logCat如下;

09-22 22:22:23.634 1808-1808/com.revosleap.movielist E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.revosleap.movielist, PID: 1808
java.lang.IllegalStateException: Cannot change whether this adapter has stable IDs while the adapter has registered observers.
    at android.support.v7.widget.RecyclerView$Adapter.setHasStableIds(RecyclerView.java:6749)
    at com.revosleap.movielist.Utils.UrlUtils.GenreFetcher.getGenre(GenreFetcher.java:48)
    at com.revosleap.movielist.MainActivity$2.onItemSelected(MainActivity.java:221)
    at android.widget.AdapterView.fireOnSelected(AdapterView.java:1124)
    at android.widget.AdapterView.access$200(AdapterView.java:54)
    at android.widget.AdapterView$SelectionNotifier.run(AdapterView.java:1089)
    at android.os.Handler.handleCallback(Handler.java:739)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:145)
    at android.app.ActivityThread.main(ActivityThread.java:5942)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)

我该如何解决这个问题？

我是使用房间持久性的新手，每当我尝试运行我的代码时都会出现此错误。编辑时没有显示错误，但我在 gradle 上遇到构建错误。我不得不复制粘贴代码，但似乎没有任何效果，这让我很失望。错误如下

error: An entity must have at least 1 field annotated with @PrimaryKey

我该如何解决？我的代码如下；

 package com.revosleap.dummy.DatabaseMov;

import android.arch.persistence.room.ColumnInfo;
import android.arch.persistence.room.Entity;
import android.arch.persistence.room.Ignore;
import android.arch.persistence.room.PrimaryKey;

@Entity

public class TodoListItem {
    @Ignore
    @PrimaryKey(autoGenerate = true)
     private int id;

    @ColumnInfo(name = "time")
    private String time;

    @ColumnInfo(name="title")
    private String title;

    public TodoListItem(){

    }

    public TodoListItem(String time, String title) {
        this.time = time;
        this.title = title;
    }

    public String getTime() {
        return time;
    }

    public void setTime(String time) {
        this.time = time;
    } …