java - Android SQLite CustomAdapter 和自定义 ListView

Question

我是一名非常新的 Android 开发人员，我一直在尝试通过创建简单的应用程序来学习它。

现在我一直在尝试为我的应用程序创建自定义 ListView。

我的数据存储在 SQLite 中，我将这些数据称为列表。我似乎找不到一个网站来演示如何让 SQLite 数据与自定义 ListView 一起使用。

以下是我的数据，我希望有人可以帮助我设置自定义适配器以使用我的 sqlite 数据。

Records.java

public class Records {
    private long id;
    private String name;
    private String type;
    private float mf;
    private float mftop;
    private float mfbot;
    private float mfleft;
    private float mfright;
    private float rf;
    private float rftop;
    private float rfbot;
    private float rfleft;
    private float rfright;
    private float tb;
    private float tbtop;
    private float tbbot;
    private float tbleft;
    private float tbright;
    private float bridge;
    private float bridgel;
    private float bridger;

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    // Middle Finger
    public float getMF() {
        return mf;
    }

    public void setMF(float mf) {
        this.mf = mf;
    }

    public float getMFTop() {
        return mftop;
    }

    public void setMFTop(float mftop) {
        this.mftop = mftop;
    }

    public float getMFBot() {
        return mfbot;
    }

    public void setMFBot(float mfbot) {
        this.mfbot = mfbot;
    }

    public float getMFLeft() {
        return mfleft;
    }

    public void setMFLeft(float mfleft) {
        this.mfleft = mfleft;
    }

    public float getMFRight() {
        return mfright;
    }

    public void setMFRight(float mfright) {
        this.mfright = mfright;
    }

    //Ring Finger
    public float getRF() {
        return rf;
    }

    public void setRF(float rf) {
        this.rf = rf;
    }

    public float getRFTop() {
        return rftop;
    }

    public void setRFTop(float rftop) {
        this.rftop = rftop;
    }

    public float getRFBot() {
        return rfbot;
    }

    public void setRFBot(float rfbot) {
        this.rfbot = rfbot;
    }

    public float getRFLeft() {
        return rfleft;
    }

    public void setRFLeft(float rfleft) {
        this.rfleft = rfleft;
    }

    public float getRFRight() {
        return rfright;
    }

    public void setRFRight(float rfright) {
        this.rfright = rfright;
    }

    //Thumb
    public float getTB() {
        return tb;
    }

    public void setTB(float tb) {
        this.tb = tb;
    }

    public float getTBTop() {
        return tbtop;
    }

    public void setTBTop(float tbtop) {
        this.tbtop = tbtop;
    }
    public float getTBBot() {
        return tbbot;
    }

    public void setTBBot(float tbbot) {
        this.tbbot = tbbot;
    }
    public float getTBLeft() {
        return tbleft;
    }

    public void setTBLeft(float tbleft) {
        this.tbleft = tbleft;
    }
    public float getTBRight() {
        return tbright;
    }

    public void setTBRight(float tbright) {
        this.tbright = tbright;
    }

    //Bridge
    public float getBridge() {
        return bridge;
    }

    public void setBridge(float bridge) {
        this.bridge = bridge;
    }

    public float getBridgeL() {
        return bridgel;
    }

    public void setBridgeL(float bridgel) {
        this.bridgel = bridgel;
    }

    public float getBridgeR() {
        return bridger;
    }

    public void setBridgeR(float bridger) {
        this.bridger = bridger;
    }

    //Will be used by the ArrayAdapter in the ListView
    @Override
    public String toString() {
        return name;
    }

}

CustomAdapter.java

public class CustomAdapter extends ArrayAdapter<NTAdapter> {

    Context context;
    int layoutResourceId;
    NTAdapter data[] = null;

    public CustomAdapter(Context context, int layoutResourceId, NTAdapter[] data) {
        super(context, layoutResourceId, data);
        // TODO Auto-generated constructor stub
        this.layoutResourceId = layoutResourceId;
        this.context = context;
        this.data = data;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub

        View row = convertView;
        DataHolder holder = null;

        if (row == null) {
            LayoutInflater inflater = ((Activity)context).getLayoutInflater();
            row = inflater.inflate(layoutResourceId, parent, false);

            holder = new DataHolder();
            holder.dataName = (TextView)row.findViewById(R.id.dataName);
            holder.dataType = (TextView)row.findViewById(R.id.dataType);

            row.setTag(holder);
        } else {
            holder = (DataHolder)row.getTag();
        }

        NTAdapter ntadapter = data[position];
        holder.dataName.setText(ntadapter.name);
        holder.dataType.setText(ntadapter.type);

        return row;
    }

    static class DataHolder {
        TextView dataName;
        TextView dataType;
    }

}

NTAdapter.java

public class NTAdapter {

    public int id;
    public String name, type;

    public NTAdapter() {
        super();
    }

    public NTAdapter(int id, String name, String type) {
        super();
        this.id = id;
        this.name = name;
        this.type = type;
    }
}

DataLayout.java

public class DataLayout extends ListActivity {
    private RecordsDataSource datasource;

    Button btnDataCancel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.data_layout);


        datasource = new RecordsDataSource(this);
        datasource.open();

        List<Records> values = datasource.getAllRecords();

        //use the SimpleCursorAdapter to show the
        //elements in a ListView
        ArrayAdapter<Records> adapter = new ArrayAdapter<Records>(this, android.R.layout.simple_list_item_1, values);
        setListAdapter(adapter);

        /**
        CustomAdapter adapter = new CustomAdapter(this, R.layout.data_layout_listview, values);
        listView1 = (ListView)findViewById(R.id.listView1);

        listView1.setAdapter(adapter);
        */

        Button btnDataCancel = (Button)findViewById(R.id.btnDataCancel);

        //Cancel Button
        btnDataCancel.setOnClickListener(new View.OnClickListener() {

            public void onClick(View arg0) {
                //Starting a new Intent
                Intent goMain = new Intent(getApplicationContext(), MainActivity.class);

                startActivity(goMain);
                finish();
            }
        });
    }

    @Override
    protected void onResume() {
        datasource.open();
        super.onResume();
    }

    @Override
    protected void onPause() {
        datasource.close();
        super.onPause();
    }


}

请注意，在我的 DataLayout.java 中，我一直在尝试让我的 sqlite 数据与我的自定义 ListView 设置一起使用。

        /**
        CustomAdapter adapter = new CustomAdapter(this, R.layout.data_layout_listview, values);
        listView1 = (ListView)findViewById(R.id.listView1);

        listView1.setAdapter(adapter);
        */

我确实知道我的问题是我的 NTAdapter.java 和 CustomAdapter.java 没有正确设置。但是，我不知道如何修复它，以便它接受存储在 values

中的数据列表

由于代码开始变得有点太长而难以阅读，我没有发布我的其他类(class)。但请注意，如果我不使用自定义 ListView ，一切都会正常工作，因为它尚未工作。

任何帮助将不胜感激。预先感谢您。

编辑:另外，我知道 NTAdapter 并不是真正需要的，但我不知道如何制作它，以便我的 CustomAdapter.java 将从我的 值 中获取数据并使用它们设置我的自定义 ListView。

edit2:对于那些想知道值是什么的人，请参阅DataLayout.java。

.

Answer 1

您在制作 CustomAdapter 时所做的是尝试传递一个 List 到接受 NTAdapter 数组的构造函数。所以你的程序不应该正常工作。

您可以做的就是使您的 CustomAdapter 类类似于以下内容:

public class CustomAdapter extends ArrayAdapter<Records> {

Context context;
int layoutResourceId;
List<Records> data;


public CustomAdapter(Context context, int layoutResourceId, ArrayList<Records> data) {
    super(context, layoutResourceId, data);
    // TODO Auto-generated constructor stub
    this.layoutResourceId = layoutResourceId;
    this.context = context;
    this.data=data;

}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub

    View row = convertView;
    DataHolder holder = null;

    if (row == null) {
        LayoutInflater inflater = ((Activity)context).getLayoutInflater();
        row = inflater.inflate(layoutResourceId, parent, false);

        holder = new DataHolder();
        holder.dataName = (TextView)row.findViewById(R.id.dataName);
        holder.dataType = (TextView)row.findViewById(R.id.dataType);

        row.setTag(holder);
    } else {
        holder = (DataHolder)row.getTag();
    }

    Records records = data.get(position);
    holder.dataName.setText(records.getName());
    holder.dataType.setText(records.getType());

    return row;
}

static class DataHolder {
    TextView dataName;
    TextView dataType;
}