位置をその値/選択に設定する前に、スピナーに値/選択が含まれていることを確認できるかどうか疑問に思っていました。私がやっていることは、顧客が製品のオプションを持っているということです EX: RED、YELLOW、GREEN. 彼らが選択すると、それは私のDBに記録されます。顧客が編集するアイテムをロードしたら、スピナーの位置をその選択に設定する必要があります。私は問題なくこれを行うことができます。問題は、ユーザーが再度ログインして 1 週間後にカートが再表示された場合、オプションが利用できなくなる可能性があるため、選択する前にまだ利用できることを確認する必要があることです。私はする必要があると思う ArrayList をチェックしようとしましたが、完全にはわかりません。試してみましたが、アプリがクラッシュします。何か案は？前もって感謝します。以下は私のコードです。
選択したオプションを読み込み中:
ArrayAdapter<String> spinnerOpt1;
ArrayAdapter<String> spinnerOpt2;
ArrayAdapter<String> spinnerOpt3;
class LoadSelectedOptions extends AsyncTask<String, String, String> {
@Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
Log.d("CONFIRM SPIN STAT 1::", Integer.toString(SpinStat1));
if(SpinStat1==1){
Log.d("SPINSTAT1", Integer.toString(SpinStat1));
List<NameValuePair> Options = new ArrayList<NameValuePair>();
Options.add(new BasicNameValuePair(DO_FUNCTION, SEL_OPT_FUNCTION1));
Options.add(new BasicNameValuePair(SEL_ITEM_COUNT, theProduct_Number));
JSONObject json = jParser.makeHttpRequest(master_url, "GET", Options);
Log.d("SPINSTAT1", json.toString());
try{
sel_success1 = json.getInt(SEL_SUCCESS1);
JSONArray selected_1 = json.getJSONArray(OPT_CATAGORIES);
if (sel_success1 == 1) {
for (int i = 0; i < selected_1.length(); i++) {
JSONObject c = selected_1.getJSONObject(i);
sel_opt1 = c.getString(SEL_OPT1);
}
}else {
}
}catch (JSONException e) {
e.printStackTrace();
}
}
if(SpinStat2==1){
List<NameValuePair> Options2 = new ArrayList<NameValuePair>();
Options2.add(new BasicNameValuePair(DO_FUNCTION, SEL_OPT_FUNCTION2));
Options2.add(new BasicNameValuePair(SEL_ITEM_COUNT, theProduct_Number));
JSONObject json2 = jParser.makeHttpRequest(master_url, "GET", Options2);
try{
sel_success2 = json2.getInt(SEL_SUCCESS2);
JSONArray selected_2 = json2.getJSONArray(OPT_CATAGORIES);
if (sel_success2 == 1) {
for (int i = 0; i < selected_2.length(); i++) {
JSONObject c = selected_2.getJSONObject(i);
sel_opt2 = c.getString(SEL_OPT2);
}
}else {
}
}catch (JSONException e) {
e.printStackTrace();
}
}
if(SpinStat3==1){
List<NameValuePair> Options3 = new ArrayList<NameValuePair>();
Options3.add(new BasicNameValuePair(DO_FUNCTION, SEL_OPT_FUNCTION3));
Options3.add(new BasicNameValuePair(SEL_ITEM_COUNT, theProduct_Number));
JSONObject json3 = jParser.makeHttpRequest(master_url, "GET", Options3);
try{
sel_success3 = json3.getInt(SEL_SUCCESS3);
JSONArray selected_3 = json3.getJSONArray(OPT_CATAGORIES);
if (sel_success3 == 1) {
for (int i = 0; i < selected_3.length(); i++) {
JSONObject c = selected_3.getJSONObject(i);
sel_opt3 = c.getString(SEL_OPT3);
}
}else {
}
}catch (JSONException e) {
e.printStackTrace();
}
}
return null;
}
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
runOnUiThread(new Runnable(){
@Override
public void run() {
// TODO Auto-generated method stub
//SpinStat is a value determining if there are options. 0==No Options 1==Options Are Available
if(SpinStat1==1){
//spinnerOpt1 is the ArrayAdapter for that specific spinner. It is loaded from a List/ArrayList "options1"
}else if(spinnerOpt1.equals(sel_opt1)){
Spinner1.setSelection(spinnerOpt1.getPosition(sel_opt1));
}
if(SpinStat2==1){
}else if(spinnerOpt2.equals(sel_opt2)){
Spinner2.setSelection(spinnerOpt2.getPosition(sel_opt2));
}
if(SpinStat3==1){
}else if(spinnerOpt3.equals(sel_opt3)){
Spinner3.setSelection(spinnerOpt3.getPosition(sel_opt3));
}
}
});
}
}
ログキャット::
07-16 13:41:49.875: E/AndroidRuntime(20378): FATAL EXCEPTION: main
07-16 13:41:49.875: E/AndroidRuntime(20378): java.lang.NullPointerException
07-16 13:41:49.875: E/AndroidRuntime(20378): at com.example.shopper.EditCart$LoadSelectedOptions$1.run(EditCart.java:689)
07-16 13:41:49.875: E/AndroidRuntime(20378): at android.app.Activity.runOnUiThread(Activity.java:4784)
07-16 13:41:49.875: E/AndroidRuntime(20378): at com.example.shopper.EditCart$LoadSelectedOptions.onPostExecute(EditCart.java:675)
07-16 13:41:49.875: E/AndroidRuntime(20378): at com.example.shopper.EditCart$LoadSelectedOptions.onPostExecute(EditCart.java:1)
07-16 13:41:49.875: E/AndroidRuntime(20378): at android.os.AsyncTask.finish(AsyncTask.java:631)
07-16 13:41:49.875: E/AndroidRuntime(20378): at android.os.AsyncTask.access$600(AsyncTask.java:177)
07-16 13:41:49.875: E/AndroidRuntime(20378): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
07-16 13:41:49.875: E/AndroidRuntime(20378): at android.os.Handler.dispatchMessage(Handler.java:99)
07-16 13:41:49.875: E/AndroidRuntime(20378): at android.os.Looper.loop(Looper.java:137)
07-16 13:41:49.875: E/AndroidRuntime(20378): at android.app.ActivityThread.main(ActivityThread.java:4898)
07-16 13:41:49.875: E/AndroidRuntime(20378): at java.lang.reflect.Method.invokeNative(Native Method)
07-16 13:41:49.875: E/AndroidRuntime(20378): at java.lang.reflect.Method.invoke(Method.java:511)
07-16 13:41:49.875: E/AndroidRuntime(20378): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1008)
07-16 13:41:49.875: E/AndroidRuntime(20378): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:775)
07-16 13:41:49.875: E/AndroidRuntime(20378): at dalvik.system.NativeStart.main(Native Method)
スピナーへのオプションのロード::
class LoadOptions1 extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
try {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair(DO_FUNCTION, OPT_FUNCTION));
params.add(new BasicNameValuePair("PROD_ID", GET_PID));
// getting JSON string from URL
Log.d("PROD_ID", GET_PID);
Log.d("DO_FUNCTION", OPT_FUNCTION);
Log.d("master_url", master_url);
JSONObject json = jParser.makeHttpRequest(master_url, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Options: ", json.toString());
// Checking for SUCCESS TAG
success2 = json.getInt(OPT_SUCCESS);
Log.d("success2", Integer.toString(success2));
if (success2 == 1) {
// products found
// Getting Array of Products
JSONArray catagories = json.getJSONArray(OPT_CATAGORIES);
// looping through All Products
for (int i = 0; i < catagories.length(); i++) {
JSONObject c = catagories.getJSONObject(i);
// Storing each json item in variable
String category = c.getString(OPT_CATAGORY);
options1.add(category);
}
} else {
// no products found
// Launch Add New product Activity
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
if (!(success2 == 0)) {
SpinStat1 = 1;
Log.d("SET SPIN STAT 1::", Integer.toString(SpinStat1));
spinnerOpt1 = new ArrayAdapter<String>(EditCart.this, android.R.layout.simple_list_item_1, options1);
Spinner1.setAdapter(spinnerOpt1);
// MySpinner.setSelection(spinnerMenu.getPosition("Select A Catagory"));
}else{
textView8.setVisibility(View.GONE);
Spinner1.setVisibility(View.GONE);
SpinStat1 = 0;
}
}
}
答え:: リストと照らし合わせて値を確認してください。
if(SpinStat1==1){
}else if(options1.contains(sel_opt1)){
Spinner1.setSelection(spinnerOpt1.getPosition(sel_opt1));
}