Question

我想从RecyclerView.Adapter类调用ActivityClass.java中的函数。

下面是我的ActivityClass.java函数：

public void payslipActivityNav() {

        Bundle b = new Bundle();
        if (b != null) {
            Intent intent = new Intent(HomePage.this, PayslipActivity.class);
            b.putString("UserName", lblUserName.getText().toString());
            b.putString("UserDesignation", lblDesignation.getText().toString());
            intent.putExtras(b);
            startActivity(intent);
        }
    }

这是我的RecyclerView.Adapter类中的类：

    public class SingleItemRowHolder extends RecyclerView.ViewHolder {

            protected TextView tvTitle;

            protected ImageView itemImage;
            protected TextView lblDescription;

            public SingleItemRowHolder(final View view) {
                super(view);

                this.tvTitle = (TextView) view.findViewById(R.id.tvTitle);
                this.itemImage = (ImageView) view.findViewById(R.id.itemImage);
                this.lblDescription = (TextView) view.findViewById(R.id.lblDescription);


                view.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        strSelectedText = tvTitle.getText().toString();
                        Toast.makeText(v.getContext(), strSelectedText, Toast.LENGTH_SHORT).show();

                        switch (strSelectedText){
                            case "Pay":
                                ((ActivityClass)mContext).payslipActivityNav();
                                break;

                        }




                    }
                });


            }

 }

这是我得到的错误java.lang.ClassCastException: android.app.Application cannot be cast to packageName.ActivityClass

我访问ActivityClass方法有什么问题吗？或者，方法调用是在内部类内部还是在RecyclerView.Adapter类中的任何其他位置执行。

帮助将不胜感激。

提前致谢！

更新

我用这个来解决它。我想到了一些东西，我尝试了这个并且它有效：

switch (strSelectedText){
                      case "Pay":
                            Intent intent = new Intent(mContext.getApplicationContext(), ActivityClass.class);
                            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                            mContext.startActivity(intent);
                            break;

                    }

谢谢大家。

Answer 1

试试这个：（（YourActivity）context）.your_method（）; //方法应公开

Answer 2

public static void payslipActivityNav() {

    Bundle b = new Bundle();
    if (b != null) {
        Intent intent = new Intent(HomePage.this, PayslipActivity.class);
        b.putString("UserName", lblUserName.getText().toString());
        b.putString("UserDesignation", lblDesignation.getText().toString());
        intent.putExtras(b);
        startActivity(intent);
    }
}

public class SingleItemRowHolder扩展了RecyclerView.ViewHolder {

        protected TextView tvTitle;

        protected ImageView itemImage;
        protected TextView lblDescription;

        public SingleItemRowHolder(final View view) {
            super(view);

            this.tvTitle = (TextView) view.findViewById(R.id.tvTitle);
            this.itemImage = (ImageView) view.findViewById(R.id.itemImage);
            this.lblDescription = (TextView) view.findViewById(R.id.lblDescription);


            view.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    strSelectedText = tvTitle.getText().toString();
                    Toast.makeText(v.getContext(), strSelectedText, Toast.LENGTH_SHORT).show();

                    switch (strSelectedText){
                        case "Pay":
                            ActivityClass.payslipActivityNav();
                            break;

                    }




                }
            });


        }

}

Answer 3

你必须使用回调接口来做到这一点。这是实现这一目标的安全方式。另外，转换上下文不会使代码可重用。

您应该在适配器内创建一个接口并通过它传递值。

您的适配器代码应如下所示：

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {

private OnItemClickListener onItemClickListener;

@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

}

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

}

@Override
public int getItemCount() {

}

public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
    this.onItemClickListener = onItemClickListener;
}

public void setData(List<AccountProvider> accountProviders) {
    this.accountProviders = accountProviders;
    notifyDataSetChanged();
}

class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

    MyViewHolder(View itemView) {
        super(itemView);
        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        if (onItemClickListener != null)
            onItemClickListener.onItemClick(tvTitle.getText().toString());
    }
}
}

<强>接口

public interface OnItemClickListener {
      void onItemClick(String value);
}

在活动：

中

public MyActivity implements OnItemClickListener{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
    MyAdapter adapter = new MyAdapter();
    adapter.setOnItemClickListener(this);
    yourRecyclerView.setAdapter(adapter);
    }

    @Override
    public void onItemClick(String value){
      switch (strSelectedText){
        case "Pay":
          payslipActivityNav();
          break;
       }
    }

}

如果您需要来自适配器的任何值，您可以通过界面传递它。

希望有所帮助：）

android - 如何从RecyclerView.Adapter访问/调用ActivityClass.java中的方法

3 个答案: