Question

最新编辑--------------------------------------------- ------------------------------- 我更新了代码，现在它是正确的，虽然我无法运行该功能。在长时间点击事件中没有任何事情发生......

在我的文件中显示来自数据库的行列表我放置了用于设置OnLongClickListener的代码，但部分代码（已注释）返回错误：The constructor ListView(Monday.MyDiary) is undefined。

以下是插入新代码的文件：

package com.example.classorganizer;


import java.util.ArrayList;

import android.app.ListActivity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;

import com.cookbook.data.Constants;
import com.cookbook.data.MyDB;






public class Monday extends ListActivity {



private static final int MyMenu = 0;
MyDB dba;
DiaryAdapter myAdapter;

private class MyDiary{
    public MyDiary(String t, String c){
        title=t;
        content=c;

        ListView listView = new ListView(this); //here the error pops out
        listView.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                new EditListItemDialog(v.getContext()).show();
                return true;
            }
        });

}

    public String title;
    public String content;

}
@Override
protected void onCreate(Bundle savedInstanceState) {
    dba = new MyDB(this);
    dba.open();
    setContentView(R.layout.fragment_monday);



    super.onCreate(savedInstanceState);
    myAdapter = new DiaryAdapter(this);
    this.setListAdapter(myAdapter);
}



private class DiaryAdapter extends BaseAdapter {
    private LayoutInflater mInflater;
    private ArrayList<MyDiary> fragment_monday;
    public DiaryAdapter(Context context) {
        mInflater = LayoutInflater.from(context);
        fragment_monday = new ArrayList<MyDiary>();
        getdata();


    }

    public void getdata(){
        Cursor c = dba.getdiaries();
        startManagingCursor(c);
        if(c.moveToFirst()){
            do{
                String title =
                        c.getString(c.getColumnIndex(Constants.TITLE_NAME));
                String content =
                        c.getString(c.getColumnIndex(Constants.CONTENT_NAME));

                MyDiary temp = new MyDiary(title,content);
                fragment_monday.add(temp);
            } while(c.moveToNext());
        }

    }



    @Override
    public int getCount() {return fragment_monday.size();}
    public MyDiary getItem(int i) {return fragment_monday.get(i);}
    public long getItemId(int i) {return i;}
    public View getView(int arg0, View arg1, ViewGroup arg2) {
        final ViewHolder holder;
        View v = arg1;
        if ((v == null) || (v.getTag() == null)) {
            v = mInflater.inflate(R.layout.diaryrow,  null);
            holder = new ViewHolder();
            holder.mTitle = (TextView)v.findViewById(R.id.name);

            v.setTag(holder);
        } else {
            holder = (ViewHolder) v.getTag();
        }

        holder.mdiary = getItem(arg0);
        holder.mTitle.setText(holder.mdiary.title);


        v.setTag(holder);

        return v;


    }

    public class ViewHolder {
        MyDiary mdiary;
        TextView mTitle;


    }

}




/** Called when the user clicks the Edit button */
public void visitDiary(View view) {
    Intent intent = new Intent(this, Diary.class);
    startActivity(intent);
}
/** Called when the user clicks the back button */
public void visitSchedule(View view) {
    Intent intent = new Intent(this, DisplayScheduleScreen.class);
    startActivity(intent);
}


}

我还创建了一个Dialog文件：

package com.example.classorganizer;

import android.app.Dialog;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

class EditListItemDialog extends Dialog implements View.OnClickListener {

private View editText;

public EditListItemDialog(Context context) {
    super(context);
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.edit_text_dialog);//here is your xml with EditText and 'Ok' and 'Cancel' buttons
    View btnOk = findViewById(R.id.button_ok);
    editText = findViewById(R.id.edit_text);
    btnOk.setOnClickListener(this);
}

@Override
public void onClick(View v) {
    ((TextView) editText).getText().toString();//here is your updated(or not updated) text
    dismiss();
}
}

我不知道如何解决这个问题。我想要实现的是通过长按它们来编辑列表中显示的行的功能。

EDIT ---------------------------------------------- ------------------------------------

现在代码看起来像这样：

ListView listView = new ListView(Monday.this);
        listView.setOnItemLongClickListener(new View.OnItemLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                new EditListItemDialog(v.getContext()).show();
                return true;
            }
        });

第二行的View.OnItemLongClickListener出现错误

EDIT ---------------------------------------------- ----------------------------------------

更新的代码没有错误，但不确定它是否正确：

ListView listView = new ListView(Monday.this);
        listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
                new EditListItemDialog(view.getContext()).show();
                return true;
            }
        });

Answer 1

Listview不能setonLongClickListener你应该实现setOnItemItemLongClickListener因为ListView包含项目列表，所以你总是可以实现其项目长按一下监听器下面：

listView.setOnItemLongClickListener(new OnItemLongClickListener() {

        @Override
        public boolean onItemLongClick(AdapterView<?> parent, View view,
                int position, long id) {
            // TODO Auto-generated method stub
            return false;
        }
    });

Answer 2

ListView listView = new ListView(this);

您应该向ListView构造函数传递一个上下文，而不是MyDiary对象。

使用

修复它

ListView listView = new ListView(Monday.this);

它应该有用，因为你的MyDiary是星期一的内部类，并不是静态的。

如果你改变这个，你应该将活动的Context传递给MyDiary构造函数并使用它。

并且，对于您的下一个问题：您应该在ListView中使用OnItemLongClickListener，而不是OnLongClickListener。

我无法设置onLongClick Listener

2 个答案: