Android 如何在Cards recylerView中获取Onclick按钮值

它显示空对象错误。 当我获取卡RecylerView上的按钮值时

Process: com.softedge.visioneering.tfd, PID: 9884
                  java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Integer.intValue()' on a null object reference
                      at com.softedge.visioneering.tfd.adapters.MyOrdersAdapter$MyOrdersViewHolder$1.onClick(MyOrdersAdapter.java:138)
                      at android.view.View.performClick(View.java:5609)

This Is My Adapter and Button Code:

public class MyOrdersViewHolder extends RecyclerView.ViewHolder {

        public TextView txtOrderDescription, txtOrderQuantity, txtOrderStatus, txtOrderDate, txtExpectedDate, txtCreatedBy,txtOrderStatus_Per;
String check;
        public Button update_btwn;
        public MyOrdersViewHolder(View convertView) {
            super(convertView);
            update_btwn=(Button) convertView.findViewById(R.id.status_update_button);

            final FragmentManager fragmentManager = ((FragmentActivity) context).getSupportFragmentManager();

            update_btwn.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                     id = (Integer) update_btwn.getTag();

                   fragmentManager.beginTransaction().replace(R.id.container, new Status_update_Fragment().newInstance()).addToBackStack(" ").commit();
                    //((FragmentActivity) context).getSupportFragmentManager().beginTransaction().
                    // remove(((FragmentActivity) context).getSupportFragmentManager().findFragmentById(R.id.container)).commit();

                }

            });

我想对按钮执行一个操作。

---

Cards RecylerView中的哪个位置

您在按钮上设置了标签吗

Process: com.softedge.visioneering.tfd, PID: 9884
                  java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Integer.intValue()' on a null object reference
                      at com.softedge.visioneering.tfd.adapters.MyOrdersAdapter$MyOrdersViewHolder$1.onClick(MyOrdersAdapter.java:138)
                      at android.view.View.performClick(View.java:5609)

This Is My Adapter and Button Code:

public class MyOrdersViewHolder extends RecyclerView.ViewHolder {

        public TextView txtOrderDescription, txtOrderQuantity, txtOrderStatus, txtOrderDate, txtExpectedDate, txtCreatedBy,txtOrderStatus_Per;
String check;
        public Button update_btwn;
        public MyOrdersViewHolder(View convertView) {
            super(convertView);
            update_btwn=(Button) convertView.findViewById(R.id.status_update_button);

            final FragmentManager fragmentManager = ((FragmentActivity) context).getSupportFragmentManager();

            update_btwn.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                     id = (Integer) update_btwn.getTag();

                   fragmentManager.beginTransaction().replace(R.id.container, new Status_update_Fragment().newInstance()).addToBackStack(" ").commit();
                    //((FragmentActivity) context).getSupportFragmentManager().beginTransaction().
                    // remove(((FragmentActivity) context).getSupportFragmentManager().findFragmentById(R.id.container)).commit();

                }

            });

您可以调用

.setTag（）

或在xml

android:tag=“”

中调用

另外，您不应该在视图持有者的构造函数中设置click listener，而应该在

onBindViewHolder

中进行设置

在适配器的

onBindViewHolder

方法中使用

setTag（）

：

@Override
public void onBindViewHolder(myViewHolder viewHolder, int position) {
    viewHolder.mCardView.setTag(position);
}

其中，

mCardView

在

myViewHolder

类中定义

private class myViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
           public View mCardView;

           public myViewHolder(View view) {
               super(view);
               mCardView = (CardView) view.findViewById(R.id.card_view);

               mCardView.setOnClickListener(this);
           }
       }

在

OnClickListener

实现中使用

getTag（）

：

@Override
public void onClick(View view) {
        int position = (int) view.getTag();           

    //display toast with position of cardview in recyclerview list upon click
    Toast.makeText(view.getContext(),Integer.toString(position),Toast.LENGTH_SHORT).show();
}

---

你需要在得到它之前设置标签。我们如何做请告诉我只是想知道在card recylerView

update\u btwn.setTag（“uniqueId/name”）

中按下哪个按钮，就像这个标签一样，点击一下就得到那个标签