Question

我创建了一个输入类，例如3个输入Map：String，List，List，然后在RecyclerView中使用它在我的构造函数中，我在列表中输入字符串然后清除它，所以我必须从mainExampleClass

获取我的数据

我该如何访问它？例如，在包含示例列表的列表中

List<Example> exampleList;
exampleList.get(0);

如何在get(i)之后访问数据？

RecylerView数据对象：

public class Example {
    private static MainExampleObject exampleObject;
    private static String StepName;
    private static List<String> TemporaryCode = new ArrayList<>(), TemporaryExplanation = new ArrayList<>();

    public Example(MainExampleObject exampleObject) {
        this.exampleObject = exampleObject;
    }

    public static void addCode(String code) {
        TemporaryCode.add(code);
    }

    public static void addExplanation(String explanation) {
        TemporaryExplanation.add(explanation);
    }

    public static void setStepName(String stepName) {
        StepName = stepName;
    }

    public static MainExampleObject getExampleObject() {
        return exampleObject;
    }

    static List<String> getTemporaryCode() {
        return TemporaryCode;
    }

    static List<String> getTemporaryExplanation() {
        return TemporaryExplanation;
    }

    static String getStepName() {
        return StepName;
    }

    public static void addExample(){
        exampleObject = new MainExampleObject(StepName, TemporaryCode, TemporaryExplanation);
        TemporaryCode.clear();
        TemporaryExplanation.clear();
    }

}

示例对象类：

class MainExampleObject {
    private static String StepName;
    private static List<String> Code, Explanation;

    MainExampleObject(String stepHeader, List<String> code, List<String> explanation) {
        StepName = stepHeader;
        Code = code;
        Explanation = explanation;
    }

    public static String getStepNamex() {
        return StepName;
    }

}

更多详情

我将数据添加到列表

的方法

public void onChildAdded(DataSnapshot dataSnapshot, String s) {
                Example.setStepName(String.valueOf(dataSnapshot.getKey()));

                for (DataSnapshot childSnapshot : dataSnapshot.child("Code").getChildren()) {
                    Example.addCode(String.valueOf(childSnapshot.getValue()));
                }

                for (DataSnapshot childSnapshot : dataSnapshot.child("Explaination").getChildren()) {
                    Example.addExplanation(String.valueOf(childSnapshot.getValue()));
                }
                addExample();
                exampleList.add(new Example(getExampleObject()));
                adapter.notifyDataSetChanged();
            }

适配器

List<Example> exampleList;
    ViewLesson viewLesson;

    public interface OnItemSelectedListenerCustom {
        void onItemClicked(int selectedPosition);
    }

    public class ExampleHolder extends RecyclerView.ViewHolder {  // here is where you define what text have value
        CardView cv;
        LinearLayout ll;

        public ExampleHolder(View itemView) {
            super(itemView);
            cv = (CardView) itemView.findViewById(R.id.CV);
            ll = (LinearLayout) itemView.findViewById(R.id.CV_LL);
        }
    }

    public ExampleAdapter(ViewLesson viewLesson, List<Example> exampleList) {
        this.viewLesson = viewLesson;
        this.exampleList = exampleList;
    }


    @Override
    public ExampleHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.card_view, parent, false);
        return new ExampleHolder(itemView);
    }

    @Override
    public void onBindViewHolder(final ExampleHolder holder, int position) {

        TextView tv = new TextView(holder.cv.getContext());
        if (Example.getStepName() != null) {
            tv.setText(Example.getStepName());
            holder.ll.addView(tv);
        }

        if (Example.getTemporaryCode() != null && Example.getTemporaryExplanation() != null) {
            int i = 0;
            for (String code : Example.getTemporaryCode()) {
                tv = new TextView(holder.cv.getContext());
                tv.setText(code);
                holder.ll.addView(tv);

                tv = new TextView(holder.cv.getContext());
                tv.setText(Example.getTemporaryCode().get(i));
                holder.ll.addView(tv);
                i++;
            }
            tv = new TextView(holder.cv.getContext());
            tv.setText(String.valueOf(exampleList.get(0).getClass().toString()));
            holder.ll.addView(tv);

            tv = new TextView(holder.cv.getContext());
            tv.setText(String.valueOf(exampleList.get(1).getClass().toString()));
            holder.ll.addView(tv);
        }
    }

    @Override
    public int getItemCount() {
        return exampleList.size();
    }
}

这是我想要单独获取此数据示例

的确切行

StepName = 2 Adding b, TemporaryCode = [1aaaa, 2baaa, 3caaa], TemporaryExplanation = [1sttt, 2nddd, 3rddd]

其中

字符串为2 Adding b
第一个列表是[1aaaa, 2baaa, 3caaa]
第二个列表是[1sttt, 2nddd, 3rddd]

The Line

tv.setText(String.valueOf(exampleList.get(0).getClass().toString()));

Answer 1

基于这一行，你似乎想要一个String表示你班级中的所有变量。

 exampleList.get(0).getClass().toString()

好吧，getClass()会返回一个Java类变量，Class上的toString不会告诉你的字段。

请参阅here并将其应用到您的班级之后您修复了您认为自己需要的所有内容static无处不在

如果操作正确，这将有效。

 setText(String.valueOf(exampleList.get(0)))

获取对象列表的数据

1 个答案: