Question

我对Fragment上的事件OnClickListener有一个问题。

我使用的是Android Studio 3.1
这是我的源代码的捕获：

焦点到黄色突出显示，如果源代码我给出评论声明运行它已经没问题。但是，当我取消注释时，它会让我的应用程序受力关。

然后我尝试通过在XML上提供事件onClick来更改方法，但不能在课堂上使用method

Answer 1

如果在XML中声明View，则需要传递android:onclick="method"参数。

此外，您需要在活动中声明此方法（不在片段中）。

public void method(View view)
{
    Toast.makeText(getActivity(),"Button is clicked",Toast.LENGTH_SHORT).show();
}

在Java代码中，

button.setOnClickListener(new OnClickListener() {
    public void onClick(View v)
    {
        Toast.makeText(getActivity(),"Button is clicked",Toast.LENGTH_SHORT).show();
    }     
});

Answer 2

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.HashMap;

public class UncompleteFragment extends Fragment implements View.OnClickListener {

    private ArrayList<HashMap<String,String>> list;
    private SimpleAdapter sa;
    private HashMap<String,String> item;
    private ListView listView;
    private Button btnEdit;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        final View rootView = inflater.inflate(R.layout.uncomplete, container, false);
        listView = rootView.findViewById(R.id.list);
        btnEdit = rootView.findViewById(R.id.btn_edit_uncomplete);
        btnEdit.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v)
            {
                Toast.makeText(getActivity(), "Button Edit Clicked!", Toast.LENGTH_SHORT).show();
            }
        });
        return rootView;
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        list = new ArrayList<HashMap<String,String>>();
        for(int i=0;i<uncomplete.length;i++){
            item = new HashMap<String,String>();
            item.put( "line1", uncomplete[i][0]);
            item.put( "line2", uncomplete[i][1]);
            item.put( "line3", uncomplete[i][2]);
            item.put( "line4", uncomplete[i][3]);
            list.add( item );
        }

        sa = new SimpleAdapter(getActivity(), list,
                R.layout.uncomplete_list,
                new String[] { "line1","line2","line3","line4"},
                new int[] {R.id.date,R.id.check_in,R.id.check_out,R.id.work_hour});

        listView.setAdapter(sa);
    }

    private String[][] uncomplete =
            {{"12 Apr 2018","08:00","14:00","05:00"},
             {"27 Mar 2018","00:00","00:00","00:00"},
             {"06 Feb 2018","08:00","00:00","00:00"}};

    public void doEdit() {
        Toast.makeText(getActivity(), "Button Edit Clicked!", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onClick(View view) {

    }
}

片段上的OnClickListener问题

2 个答案: