Question

当我尝试打开“ReadActivity”时，我的Android应用程序“电子邮件”崩溃了。

在MainActivity中声明的方法OpenMail（）应该启动ReadActivity：

public void OpenMail(View v, int index) {
    String[] mail = {"x", "y", "z"};

    Intent readIntent = new Intent(this, ReadActivity.class); <-- Error occurs here

    readIntent.putExtra("mail", mail);

    startActivity(readIntent);
}

在ListViewAdapter中调用该方法：

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    Holder holder = new Holder();

    View rowView = inflater.inflate(R.layout.listview_item, null);

    holder.imageView = (ImageView) rowView.findViewById(R.id.imageView);
    holder.txvSenderMail = (TextView) rowView.findViewById(R.id.txvSender);
    holder.txvSubject = (TextView) rowView.findViewById(R.id.txvSubject);

    holder.imageView.setImageResource(ImageID[position]);
    holder.txvSenderMail.setText(SenderMail[position]);
    holder.txvSubject.setText(Subject[position]);

    rowView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            new MainActivity().OpenMail(v, position);
        }
    });

    return rowView;
}

错误：java.lang.NullPointerException：尝试在空对象引用上调用虚拟方法'android.app.ActivityThread $ ApplicationThread android.app.ActivityThread.getApplicationThread（）'

我希望有人可以帮助我！谢谢！

Answer 1

当您执行

时，实际上是在尝试创建新的MainActivity

new MainActivity().OpenMail(v, context, position);

如果您目前在MainActivity课程中，我认为您想要做这样的事情：

getActivity().OpenMail(v, context, position);

当然，不要忘记将ReadActivity添加到AndroidManifest

Android应用崩溃创建开放的Intent

1 个答案: