Android的 - 添加列矩阵光标和显示列计数吐司导致崩溃 [英] Android - Adding Columns to Matrix Cursor and Showing Column Count Toast causing Crash
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问题描述
使用im矩阵光标行添加到游标。
在上创建在MainActivity定义的列
//在保护无效的onCreate的String [] =列新的String [] {dealername \"product\",\"type\",\"description\",\"location\",\"sublocation\",\"address\",\"phone1\",\"phone2\",\"auth\",\"brands\",\"lat\",\"lon\"};
光标=新MatrixCursor（列）;
// -----------------在asyctask doinbackground
cursor.addRow（新的String [] {json.getString（dealername），json.getString（产品）， json.getString(\"type\"),json.getString(\"description\"),json.getString(\"location\"),json.getString(\"sublocation\"),json.getString(\"address\"),json.getString(\"phone1\"),json.getString(\"phone2\"),json.getString(\"auth\"),json.getString(\"brands\"),json.getString(\"lat\"),json.getString(\"lon\")});
当我试图让光标应用程序崩溃简单列数
保护无效onPostExecute（虚空避免）{
super.onPostExecute（避免）;
Toast.makeText（getApplicationContext（），cursor.getCount（），Toast.LENGTH_LONG）.show（）;
}
更新：
私有类getdealerinfo扩展的AsyncTask＆LT;太虚，太虚，MatrixCursor＆GT; { @覆盖
在preExecute保护无效（）{
super.on preExecute（）; }
@覆盖
保护MatrixCursor doInBackground（无效参数... args）{ / *建筑参数* / 清单＆LT;＆的NameValuePair GT; PARAMS =新的ArrayList＆LT;＆的NameValuePair GT;（）;
params.add（新BasicNameValuePair（PNAME，selectedproduct））;
params.add（新BasicNameValuePair（位置，selectedlocation））; / *从URL *获取JSON字符串/
JSONObject的JSON = jParser.makeHtt prequest（dealers_url，GET，则params）; 尝试{
/ *检查成功TAG * /
INT成功= json.getInt（TAG_SUCCESS）;
如果（成功== 1）{
JSONArray JAStuff = json.getJSONArray（TAG_STUFF）; / **检查记录号** /
INT intStuff = JAStuff.length（）;
//创建数组
dealerdetailsarray =新的String [intStuff] [12];
如果（intStuff！= 0）{
的String [] = STR1新的String [JAStuff.length（）];
的for（int i = 0; I＆LT; JAStuff.length（）;我++）
{
JSON = JAStuff.getJSONObject（ⅰ）;
// startManagingCursor（光标）;
// dealerdetailsarray [0] [0] = json.getString（dealername）;
cursor.addRow（新的String [] {json.getString（dealername），json.getString（产品）， json.getString(\"type\"),json.getString(\"description\"),json.getString(\"location\"),json.getString(\"sublocation\"),json.getString(\"address\"),json.getString(\"phone1\"),json.getString(\"phone2\"),json.getString(\"auth\"),json.getString(\"brands\"),json.getString(\"lat\"),json.getString(\"lon\")}); }
}
}
}赶上（例外五）{
Log.e（测试，e.toString（））;
}
返回游标;
}
@覆盖
保护无效onPostExecute（MatrixCursor光标）{
// super.onPostExecute（避免）;
尝试
{
Toast.makeText（getApplicationContext（），cursor.getCount（），Toast.LENGTH_LONG）.show（）;
}
赶上（例外五）{
Log.e（myerror，e.getMessage（））;
}
}
} }
解决方案
您需要从返回为光标对象doInBackground（） onPostExecute（）。定义你的的AsyncTask 类
类XYZTask扩展的AsyncTask＆LT;太虚，太虚，MatrixCursor＆GT; { 保护MatrixCursor doInBackground（虚空......无效）{ .....
cursor.addRow（新的String [] {json.getString（dealername），json.getString（产品）， json.getString(\"type\"),json.getString(\"description\"),json.getString(\"location\"),json.getString(\"sublocation\"),json.getString(\"address\"),json.getString(\"phone1\"),json.getString(\"phone2\"),json.getString(\"auth\"),json.getString(\"brands\"),json.getString(\"lat\"),json.getString(\"lon\")});
返回游标;
} 保护无效onPostExecute（MatrixCursor光标）{
Toast.makeText（getApplicationContext（），cursor.getCount（），Toast.LENGTH_LONG）.show（）;
}
}
和返回光标从对象doInBackground（）作为参数传递给 onPostExecute（ ）。
编辑：
定义你的的AsyncTask 是这样的：
私有类getdealerinfo扩展的AsyncTask＆LT;无效，无效的JSONObject＆GT; { @覆盖
在preExecute保护无效（）{
super.on preExecute（）; }
@覆盖
受保护的JSONObject doInBackground（无效参数... args）{ / *建筑参数* / 清单＆LT;＆的NameValuePair GT; PARAMS =新的ArrayList＆LT;＆的NameValuePair GT;（）;
params.add（新BasicNameValuePair（PNAME，selectedproduct））;
params.add（新BasicNameValuePair（位置，selectedlocation））; / *从URL *获取JSON字符串/
JSONObject的JSON = jParser.makeHtt prequest（dealers_url，GET，则params）;
返回JSON;
}
@覆盖
保护无效onPostExecute（JSON的JSONObject）{
// super.onPostExecute（避免）;
MatrixCursor光标=新MatrixCursor（）; 尝试{
/ *检查成功TAG * /
INT成功= json.getInt（TAG_SUCCESS）;
如果（成功== 1）{
JSONArray JAStuff = json.getJSONArray（TAG_STUFF）; / **检查记录号** /
INT intStuff = JAStuff.length（）;
//创建数组
dealerdetailsarray =新的String [intStuff] [12];
如果（intStuff！= 0）{
的String [] = STR1新的String [JAStuff.length（）];
的for（int i = 0; I＆LT; JAStuff.length（）;我++）
{
JSON = JAStuff.getJSONObject（ⅰ）;
// startManagingCursor（光标）;
// dealerdetailsarray [0] [0] = json.getString（dealername）;
cursor.addRow（新的String [] {json.getString（dealername），json.getString（产品）， json.getString(\"type\"),json.getString(\"description\"),json.getString(\"location\"),json.getString(\"sublocation\"),json.getString(\"address\"),json.getString(\"phone1\"),json.getString(\"phone2\"),json.getString(\"auth\"),json.getString(\"brands\"),json.getString(\"lat\"),json.getString(\"lon\")}); }
}
}
}赶上（例外五）{
Log.e（测试，e.toString（））;
}
Toast.makeText（getApplicationContext（），cursor.getCount（），Toast.LENGTH_LONG）.show（）; }
} }
先试试这个。
Im using a matrix cursor to add rows to cursor.
Defined columns in the MainActivity on Create
//In protected void onCreate
String[] columns = new String[] { "dealername", "product","type","description","location","sublocation","address","phone1","phone2","auth","brands","lat","lon"};
cursor= new MatrixCursor(columns);
//----------------- In asyctask doinbackground
cursor.addRow(new String[] {json.getString("dealername"),json.getString("product"), json.getString("type"),json.getString("description"),json.getString("location"),json.getString("sublocation"),json.getString("address"),json.getString("phone1"),json.getString("phone2"),json.getString("auth"),json.getString("brands"),json.getString("lat"),json.getString("lon")});
When i try to get number of columns in the cursor the app simply crashes
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
Toast.makeText(getApplicationContext(), cursor.getCount(),Toast.LENGTH_LONG).show();
}
UPDATE:
private class getdealerinfo extends AsyncTask<Void,Void,MatrixCursor> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected MatrixCursor doInBackground(Void... args) {
/* Building Parameters */
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("pname",selectedproduct));
params.add(new BasicNameValuePair("location",selectedlocation));
/* getting JSON string from URL */
JSONObject json = jParser.makeHttpRequest(dealers_url, "GET", params);
try {
/* Checking for SUCCESS TAG */
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
JSONArray JAStuff = json.getJSONArray(TAG_STUFF);
/** CHECK THE NUMBER OF RECORDS **/
int intStuff = JAStuff.length();
//creating array
dealerdetailsarray =new String[intStuff][12];
if (intStuff != 0) {
String[] str1 = new String[JAStuff.length()];
for(int i=0;i<JAStuff.length();i++)
{
json=JAStuff.getJSONObject(i);
// startManagingCursor(cursor);
// dealerdetailsarray[0][0]=json.getString("dealername");
cursor.addRow(new String[] {json.getString("dealername"),json.getString("product"), json.getString("type"),json.getString("description"),json.getString("location"),json.getString("sublocation"),json.getString("address"),json.getString("phone1"),json.getString("phone2"),json.getString("auth"),json.getString("brands"),json.getString("lat"),json.getString("lon")});
}
}
}
} catch (Exception e) {
Log.e("test",e.toString());
}
return cursor;
}
@Override
protected void onPostExecute(MatrixCursor cursor) {
// super.onPostExecute(aVoid);
try
{
Toast.makeText(getApplicationContext(), cursor.getCount(),Toast.LENGTH_LONG).show();
}
catch (Exception e) {
Log.e("myerror",e.getMessage());
}
}
}
}
解决方案
You need to return the cursor object from doInBackground() to onPostExecute(). Define your AsyncTask class as
class XYZTask extends AsyncTask<Void, Void, MatrixCursor>{
protected MatrixCursor doInBackground(Void... void) {
.....
cursor.addRow(new String[] {json.getString("dealername"),json.getString("product"), json.getString("type"),json.getString("description"),json.getString("location"),json.getString("sublocation"),json.getString("address"),json.getString("phone1"),json.getString("phone2"),json.getString("auth"),json.getString("brands"),json.getString("lat"),json.getString("lon")});
return cursor;
}
protected void onPostExecute(MatrixCursor cursor) {
Toast.makeText(getApplicationContext(), cursor.getCount(),Toast.LENGTH_LONG).show();
}
}
and return the cursor object from doInBackground() as a parameter to onPostExecute().
EDIT:
Define your AsyncTask like this:
private class getdealerinfo extends AsyncTask<Void,Void,JSONObject> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected JSONObject doInBackground(Void... args) {
/* Building Parameters */
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("pname",selectedproduct));
params.add(new BasicNameValuePair("location",selectedlocation));
/* getting JSON string from URL */
JSONObject json = jParser.makeHttpRequest(dealers_url, "GET", params);
return json;
}
@Override
protected void onPostExecute(JSONObject json) {
// super.onPostExecute(aVoid);
MatrixCursor cursor = new MatrixCursor();
try {
/* Checking for SUCCESS TAG */
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
JSONArray JAStuff = json.getJSONArray(TAG_STUFF);
/** CHECK THE NUMBER OF RECORDS **/
int intStuff = JAStuff.length();
//creating array
dealerdetailsarray =new String[intStuff][12];
if (intStuff != 0) {
String[] str1 = new String[JAStuff.length()];
for(int i=0;i<JAStuff.length();i++)
{
json=JAStuff.getJSONObject(i);
// startManagingCursor(cursor);
// dealerdetailsarray[0][0]=json.getString("dealername");
cursor.addRow(new String[] {json.getString("dealername"),json.getString("product"), json.getString("type"),json.getString("description"),json.getString("location"),json.getString("sublocation"),json.getString("address"),json.getString("phone1"),json.getString("phone2"),json.getString("auth"),json.getString("brands"),json.getString("lat"),json.getString("lon")});
}
}
}
} catch (Exception e) {
Log.e("test",e.toString());
}
Toast.makeText(getApplicationContext(), cursor.getCount(),Toast.LENGTH_LONG).show();
}
}
}
Try this first.
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