如何从其他方法访问变量

Question

public class Tab1 extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.tab1, container, false);

        HorizontalBarChart barChart = (HorizontalBarChart) rootView.findViewById(R.id.barchartnew);

        ArrayList<BarEntry> bargroup1 = new ArrayList<>();
        bargroup1.add(new BarEntry(8f, 0));
        return rootView;
    }

    public void test() {
        // Here I want to access bargroup1
    }
}

如何在public void test()访问数组列表变量bargroup1 ？

我试过插入ArrayList bargroup1; 在public class Tab1 extends Fragment {并删除ArrayList<BarEntry> bargroup1 = new ArrayList<>(); 但是我的应用程序崩溃了。

Answer 1

将var声明为实例变量，在onCreateView方法中对其进行初始化，然后可以在其他方法中使用var：

public class Tab1 extends Fragment {

ArrayList<BarEntry> bargroup1;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.tab1, container, false);


    HorizontalBarChart barChart = (HorizontalBarChart)rootView.findViewById(R.id.barchartnew);

    bargroup1 = new ArrayList<>();
    bargroup1.add(new BarEntry(8f, 0));
return rootView;
}

public void test(){

        // Here I want to access bargroup1

    }

}