Question

我需要一些自定义列表视图适配器的帮助。我正在使用vogella.de中的适配器示例，但我需要找到一种如何从sqlite数据库设置文本和图像的方法。这是我正在使用的适配器代码：

import android.app.Activity;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class MyArrayAdapter extends ArrayAdapter<String> {
    private final Activity context;
    private final String[] names;
    Cursor cursor;

    public MyArrayAdapter(Activity context, String[] names) {
        super(context, R.layout.main_listview, names);
        this.context = context;
        this.names = names;
    }

    // static to save the reference to the outer class and to avoid access to
    // any members of the containing class
    static class ViewHolder {
        public ImageView imageView;
        public TextView textView,textView2;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // ViewHolder will buffer the assess to the individual fields of the row
        // layout

        ViewHolder holder;
        // Recycle existing view if passed as parameter
        // This will save memory and time on Android
        // This only works if the base layout for all classes are the same
        View rowView = convertView;
        if (rowView == null) {

            LayoutInflater inflater = context.getLayoutInflater();
            rowView = inflater.inflate(R.layout.main_listview, null, true);

            holder = new ViewHolder();
            holder.textView = (TextView) rowView.findViewById(R.id.main_name);
            holder.textView2 = (TextView) rowView.findViewById(R.id.main_info);
            holder.imageView = (ImageView) rowView.findViewById(R.id.main_img);
            rowView.setTag(holder);

        } else {
            holder = (ViewHolder) rowView.getTag();
        }
        final Bitmap b = BitmapFactory.decodeFile("/sdcard/52dde26940e0d3081f6a086d4b54cd1c.jpg", null);

        holder.textView.setText("");
        holder.textView2.setText("");
        holder.imageView.setImageBitmap(b);


        return rowView;
    }

    public String[] getNames() {
        return names;
    }
}

我正在尝试将文本设置为这样的文本视图：

 String sql = "SELECT title FROM collections";
        Cursor cursorTitle = userDbHelper.executeSQLQuery(sql);
        if(cursorTitle.getCount()==0){
            Log.i("Cursor Null","CURSOR TITLE NULL");
        } else if(cursorTitle.getCount()>0){
            cursorTitle.moveToFirst();
            String text = cursorTitle.getString(cursorTitle.getColumnIndex("title"));
            Log.i("title text","title text : "+text);
            String[] names = new String[] { text };
            listView.setAdapter(new MyArrayAdapter(this, names));
 }

，但是当我运行该代码时，我的列表视图中没有得到任何结果。

所以有人可以建议我如何使用此适配器在我的活动中设置imageview和textview中的文本和图像。

非常感谢！

Answer 1

检查出来

String text = cursorTitle.getString(cursorTitle.getColumnIndex("title"));
Log.i("title text","title text : "+text);
String[] names = new String[] { text };

LogCat中“文字”的结果是什么？存储在'names'数组中的任何值？

Answer 2

你在哪里使用适配器中的String数组，你传递给它？我想，你在两个文本视图中都设置了null。你需要像适配器中的holder.textview.setText（names [position]）一样使用它。第二件事，你应该使用for循环从cursor创建你的字符串数组。看起来你总是得到你的游标数据的第一个结果。

Answer 3

尝试做这样的事情：

MyAddapterClass：

    private final Activity context;
    private final String[] names;
    private final Bitmap image;
    private final String text;
    private final String text2;
    Cursor cursor;

    public MyArrayAdapter(Activity context, String[] names, Bitmap image, String text, String text2) {
        super(context, R.layout.main_listview, names);
        this.context = context;
        this.names = names;
        this.image = image;
        this.text = text;
        this.text2 = text2;
    }

并为您的持有人设置image，text和text2：

    holder.textView.setText(text);
    holder.textView2.setText(text2);
    holder.imageView.setImageBitmap(image);

并在您的Activity中初始化它。就是这样。

希望它有所帮助！

Android listview适配器显示来自sqlite的文本

3 个答案: