当我使用适配器时从列表视图中检索数据
Retrieving data from listview when im using adapter
我可以在我的菜单中显示 toastactivity 但现在我需要从列表视图中获取选定的数据并将其显示在另一个页面上。我尝试了很多方法并搜索了它，但我似乎无法得到它。
菜单activity :
public class MenuActivity extends Activity {
private String server = "http://172.16.156.56";
private String sql_table = "orders";
private ListView list;
private TextView txtOrder, txtMember, txtPrice;
private Button btnAdd;
ArrayList<String> rows;
ListView listView1;
Button btnSubmit;
ArrayList<CustomItem> itemList, selectedList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_menu);
list=(ListView) findViewById(R.id.listView);
btnAdd = (Button)findViewById(R.id.button);
rows = new ArrayList<String>();
itemList=new ArrayList<CustomItem>();
itemList.add(new CustomItem("Fried Rice","description","1","Quantity"));
itemList.add(new CustomItem("Fried Noodle","description","2","Quantity"));
itemList.add(new CustomItem("Prawn noodle","description","3","Quantity"));
itemList.add(new CustomItem("Chicken Rice","description","4","Quantity"));
int[] prgmImages={R.drawable.friedrice,R.drawable.friednoodle,R.drawable.pnoodle,R.drawable.chickenrice};
listView1 = (ListView) findViewById(R.id.listView);
final CustomLVAdapter customLVAdapter = new CustomLVAdapter(this, itemList,prgmImages);
listView1.setAdapter(customLVAdapter);
txtOrder = (TextView) findViewById(R.id.txt1);
txtMember = (TextView) findViewById(R.id.txt2);
txtPrice = (TextView) findViewById(R.id.txt3);
btnSubmit = (Button) findViewById(R.id.button);
btnSubmit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
StringBuffer responseText = new StringBuffer();
selectedList = new ArrayList<CustomItem>();
int total = 0;
for (int i = 0; i < itemList.size(); i++) {
CustomItem object = itemList.get(i);
if (object.isSelected()) {
responseText.append(object.getItem() + "," + object.getQty() + ",");//item
selectedList.add(object);
//calculate price
total = total + Integer.parseInt(object.getQty()) * Integer.parseInt(object.getPrice());
}
}
Add(responseText.toString(), "5565", String.valueOf(total));
Intent i = new Intent(v.getContext(), ReceiptActivity.class);
startActivity(i);
Toast.makeText(getApplicationContext(), responseText + " $" + total,
Toast.LENGTH_SHORT).show();
SelectAll();
//store in database
//go to ReceiptActivity - membership, item, totalprice
}
});
}
public void Add(final String item, final String membership, final String price)
{
RequestQueue MyRequestQueue = Volley.newRequestQueue(this);
String url = server + "/insertorder.php";
StringRequest MyStringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
}) {
protected Map<String, String> getParams() {
Map<String, String> MyData = new HashMap<String, String>();
MyData.put("item",item );
MyData.put("membership",membership );
MyData.put("price",price );
return MyData;
}
};
MyRequestQueue.add(MyStringRequest);
SelectAll();
}
public void SelectAll()
{
RequestQueue MyRequestQueue = Volley.newRequestQueue(this);
String url = server + "/fetchorder.php";
StringRequest MyStringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
try {
JSONObject jsonResponse = new JSONObject(response);
JSONArray jsonMainNode = jsonResponse.optJSONArray(sql_table);
rows.clear();
for(int i=0; i < jsonMainNode.length(); i++)
{
JSONObject jsonChildNode = jsonMainNode.getJSONObject(i);
String order = jsonChildNode.optString("item").toString();
String membership = jsonChildNode.optString("membership").toString();
String price = jsonChildNode.optString("price").toString();
rows.add(order + ", " + membership + ", " + price );
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(MenuActivity.this,
android.R.layout.simple_list_item_1, rows);
list.setAdapter(adapter);
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() { //Create an error listener to handle errors appropriately.
@Override
public void onErrorResponse(VolleyError error) {
//This code is executed if there is an error.
}
});
MyRequestQueue.add(MyStringRequest);
}
}
收据activity（我想显示结果的页面）
public class ReceiptActivity extends Activity {
static public String txtOrder = "";
TextView foodorder;
ArrayList<CustomItem> itemList, selectedList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_receipt);
CustomLVAdapter item = (CustomLVAdapter) parent.getItemAtPosition(position);
TextView foodorder = (TextView)findViewById(R.id.foodorder);
foodorder.setText("Order:" +strOrder+" ");
自定义适配器
public class CustomLVAdapter extends BaseAdapter {
private Context context;
LayoutInflater inflater;
private ArrayList<CustomItem> objectList;
private int[] imageId;
public static ArrayList<CustomItem> arl_food=new ArrayList<>();
private class ViewHolder {
TextView txt1,txt2,txt3;
CheckBox ckBox;
ImageView image;
NumberPicker np;
}
public CustomLVAdapter(Context context, ArrayList<CustomItem> objectList,int[]prgmImages){
this.context = context;
this.inflater = LayoutInflater.from(context);
this.objectList = objectList;
this.imageId = prgmImages;
}
public int getCount(){
return objectList.size();
}
public CustomItem getItem (int position) {
return objectList.get(position);
}
public long getItemId(int position) {
return position;
}
public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (convertView == null) {
holder = new ViewHolder();
convertView = inflater.inflate(R.layout.row_checkbox_textview, null);
holder.txt1 = (TextView) convertView.findViewById(R.id.txt1);
holder.txt2 = (TextView) convertView.findViewById(R.id.txt2);
holder.txt3 = (TextView) convertView.findViewById(R.id.txt3);
holder.image=(ImageView) convertView.findViewById(R.id.image);
holder.ckBox = (CheckBox) convertView.findViewById(R.id.ckBox);
holder.np = (NumberPicker) convertView.findViewById(R.id.numberPicker);
holder.np.setMinValue(0);
holder.np.setMaxValue(10);
convertView.setTag(holder);
holder.ckBox.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
CheckBox cb = (CheckBox) v;
CustomItem object = (CustomItem) cb.getTag();
Toast.makeText(context,
"You have selected: " + object.getItem() +
"Price: " + object.getPrice() +
"Qty: " + object.getQty(),
Toast.LENGTH_LONG).show();
object.setSelected(cb.isChecked());
}
}
);
holder.np.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {
@Override
public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
NumberPicker p = picker;
CustomItem object = (CustomItem) p.getTag();
object.setQty(String.valueOf(newVal));
}
});
}
else {
holder = (ViewHolder) convertView.getTag();
}
CustomItem object = objectList.get(position);
holder.txt1.setText(object.getItem());
holder.txt2.setText(object.getDesc());
holder.txt3.setText(object.getPrice());
holder.np.setTag(object);
holder.image.setImageResource(imageId[position]);
holder.ckBox.setChecked(object.isSelected());
holder.ckBox.setTag(object);
return convertView;
}
}
点击提交按钮后，您似乎已经开始 activity。现在您所要做的就是在您正在创建的意图中传递一些额外的内容。
所以当你做出意图时，你也应该这样做：
...
Intent i = new Intent(v.getContext(), ReceiptActivity.class);
i.putExtra("PRICE", price);
i.putExtra("MEMBERSHIP", membership);
i.putExtra("ITEM", item);
startActivity(i);
...
然后在您的新 activity 中，您将像这样在 onCreate 方法中读出额外内容：
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_receipt);
int price = getIntent().getStringExtra("PRICE");
String membership = getIntent().getStringExtra("MEMBERSHIP");
CustomItem item = getIntent().getStringExtra("ITEM");
...
一个警告！看起来您正在使用对象 CustomItem 表示您的项目。为了将其作为额外传递，它必须实现 Parcelable。当您实施 Parcelable 时，您将定义如何将对象及其字段转换为 "parcel" 以及如何将 "parcel" 转换回您的对象。 google docs give a pretty good example 为它。
我撒谎了，再次警告！我建议您在 ReceiptActivity 中为额外 "public static final String"s 制作密钥。这样您就可以更轻松地管理它们。
我可以在我的菜单中显示 toastactivity 但现在我需要从列表视图中获取选定的数据并将其显示在另一个页面上。我尝试了很多方法并搜索了它，但我似乎无法得到它。
菜单activity :
public class MenuActivity extends Activity {
private String server = "http://172.16.156.56";
private String sql_table = "orders";
private ListView list;
private TextView txtOrder, txtMember, txtPrice;
private Button btnAdd;
ArrayList<String> rows;
ListView listView1;
Button btnSubmit;
ArrayList<CustomItem> itemList, selectedList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_menu);
list=(ListView) findViewById(R.id.listView);
btnAdd = (Button)findViewById(R.id.button);
rows = new ArrayList<String>();
itemList=new ArrayList<CustomItem>();
itemList.add(new CustomItem("Fried Rice","description","1","Quantity"));
itemList.add(new CustomItem("Fried Noodle","description","2","Quantity"));
itemList.add(new CustomItem("Prawn noodle","description","3","Quantity"));
itemList.add(new CustomItem("Chicken Rice","description","4","Quantity"));
int[] prgmImages={R.drawable.friedrice,R.drawable.friednoodle,R.drawable.pnoodle,R.drawable.chickenrice};
listView1 = (ListView) findViewById(R.id.listView);
final CustomLVAdapter customLVAdapter = new CustomLVAdapter(this, itemList,prgmImages);
listView1.setAdapter(customLVAdapter);
txtOrder = (TextView) findViewById(R.id.txt1);
txtMember = (TextView) findViewById(R.id.txt2);
txtPrice = (TextView) findViewById(R.id.txt3);
btnSubmit = (Button) findViewById(R.id.button);
btnSubmit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
StringBuffer responseText = new StringBuffer();
selectedList = new ArrayList<CustomItem>();
int total = 0;
for (int i = 0; i < itemList.size(); i++) {
CustomItem object = itemList.get(i);
if (object.isSelected()) {
responseText.append(object.getItem() + "," + object.getQty() + ",");//item
selectedList.add(object);
//calculate price
total = total + Integer.parseInt(object.getQty()) * Integer.parseInt(object.getPrice());
}
}
Add(responseText.toString(), "5565", String.valueOf(total));
Intent i = new Intent(v.getContext(), ReceiptActivity.class);
startActivity(i);
Toast.makeText(getApplicationContext(), responseText + " $" + total,
Toast.LENGTH_SHORT).show();
SelectAll();
//store in database
//go to ReceiptActivity - membership, item, totalprice
}
});
}
public void Add(final String item, final String membership, final String price)
{
RequestQueue MyRequestQueue = Volley.newRequestQueue(this);
String url = server + "/insertorder.php";
StringRequest MyStringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
}) {
protected Map<String, String> getParams() {
Map<String, String> MyData = new HashMap<String, String>();
MyData.put("item",item );
MyData.put("membership",membership );
MyData.put("price",price );
return MyData;
}
};
MyRequestQueue.add(MyStringRequest);
SelectAll();
}
public void SelectAll()
{
RequestQueue MyRequestQueue = Volley.newRequestQueue(this);
String url = server + "/fetchorder.php";
StringRequest MyStringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
try {
JSONObject jsonResponse = new JSONObject(response);
JSONArray jsonMainNode = jsonResponse.optJSONArray(sql_table);
rows.clear();
for(int i=0; i < jsonMainNode.length(); i++)
{
JSONObject jsonChildNode = jsonMainNode.getJSONObject(i);
String order = jsonChildNode.optString("item").toString();
String membership = jsonChildNode.optString("membership").toString();
String price = jsonChildNode.optString("price").toString();
rows.add(order + ", " + membership + ", " + price );
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(MenuActivity.this,
android.R.layout.simple_list_item_1, rows);
list.setAdapter(adapter);
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() { //Create an error listener to handle errors appropriately.
@Override
public void onErrorResponse(VolleyError error) {
//This code is executed if there is an error.
}
});
MyRequestQueue.add(MyStringRequest);
}
}
收据activity（我想显示结果的页面）
public class ReceiptActivity extends Activity {
static public String txtOrder = "";
TextView foodorder;
ArrayList<CustomItem> itemList, selectedList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_receipt);
CustomLVAdapter item = (CustomLVAdapter) parent.getItemAtPosition(position);
TextView foodorder = (TextView)findViewById(R.id.foodorder);
foodorder.setText("Order:" +strOrder+" ");
自定义适配器
public class CustomLVAdapter extends BaseAdapter {
private Context context;
LayoutInflater inflater;
private ArrayList<CustomItem> objectList;
private int[] imageId;
public static ArrayList<CustomItem> arl_food=new ArrayList<>();
private class ViewHolder {
TextView txt1,txt2,txt3;
CheckBox ckBox;
ImageView image;
NumberPicker np;
}
public CustomLVAdapter(Context context, ArrayList<CustomItem> objectList,int[]prgmImages){
this.context = context;
this.inflater = LayoutInflater.from(context);
this.objectList = objectList;
this.imageId = prgmImages;
}
public int getCount(){
return objectList.size();
}
public CustomItem getItem (int position) {
return objectList.get(position);
}
public long getItemId(int position) {
return position;
}
public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (convertView == null) {
holder = new ViewHolder();
convertView = inflater.inflate(R.layout.row_checkbox_textview, null);
holder.txt1 = (TextView) convertView.findViewById(R.id.txt1);
holder.txt2 = (TextView) convertView.findViewById(R.id.txt2);
holder.txt3 = (TextView) convertView.findViewById(R.id.txt3);
holder.image=(ImageView) convertView.findViewById(R.id.image);
holder.ckBox = (CheckBox) convertView.findViewById(R.id.ckBox);
holder.np = (NumberPicker) convertView.findViewById(R.id.numberPicker);
holder.np.setMinValue(0);
holder.np.setMaxValue(10);
convertView.setTag(holder);
holder.ckBox.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
CheckBox cb = (CheckBox) v;
CustomItem object = (CustomItem) cb.getTag();
Toast.makeText(context,
"You have selected: " + object.getItem() +
"Price: " + object.getPrice() +
"Qty: " + object.getQty(),
Toast.LENGTH_LONG).show();
object.setSelected(cb.isChecked());
}
}
);
holder.np.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {
@Override
public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
NumberPicker p = picker;
CustomItem object = (CustomItem) p.getTag();
object.setQty(String.valueOf(newVal));
}
});
}
else {
holder = (ViewHolder) convertView.getTag();
}
CustomItem object = objectList.get(position);
holder.txt1.setText(object.getItem());
holder.txt2.setText(object.getDesc());
holder.txt3.setText(object.getPrice());
holder.np.setTag(object);
holder.image.setImageResource(imageId[position]);
holder.ckBox.setChecked(object.isSelected());
holder.ckBox.setTag(object);
return convertView;
}
}
点击提交按钮后，您似乎已经开始 activity。现在您所要做的就是在您正在创建的意图中传递一些额外的内容。
所以当你做出意图时，你也应该这样做：
...
Intent i = new Intent(v.getContext(), ReceiptActivity.class);
i.putExtra("PRICE", price);
i.putExtra("MEMBERSHIP", membership);
i.putExtra("ITEM", item);
startActivity(i);
...
然后在您的新 activity 中，您将像这样在 onCreate 方法中读出额外内容：
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_receipt);
int price = getIntent().getStringExtra("PRICE");
String membership = getIntent().getStringExtra("MEMBERSHIP");
CustomItem item = getIntent().getStringExtra("ITEM");
...
一个警告！看起来您正在使用对象 CustomItem 表示您的项目。为了将其作为额外传递，它必须实现 Parcelable。当您实施 Parcelable 时，您将定义如何将对象及其字段转换为 "parcel" 以及如何将 "parcel" 转换回您的对象。 google docs give a pretty good example 为它。
我撒谎了，再次警告！我建议您在 ReceiptActivity 中为额外 "public static final String"s 制作密钥。这样您就可以更轻松地管理它们。