Question

我的应用中有AutoCmpleteTextView和RecyclerView。当我从AutCompleteTextView搜索并选择一个项目时，它将添加到RecyclerView。它工作得很好。但我想知道所选项目是否已存在于RecyclerView中。避免重复项目。

这是我的代码。

final AutoCompleteTextView acTextView = (AutoCompleteTextView) findViewById(R.id.autoCompleteTextView);

        adapter = new MaterialSuggestionAdapter(getApplicationContext());
        acTextView.setAdapter(adapter);
        acTextView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Product result = adapter.getItem(position);
                String newName = result.getMatName().toString();
                String newQty = String.valueOf(result.getMatQuantity());
                String newPCode = result.getMatNo().toString();
                String newPlant = result.getMatPlant().toString();

                if (!newName.equals("")) {
                    if (myRecyclerViewAdapter.getItemCount() > 0) {
                        if (newName != myRecyclerViewAdapter.getItemName(position).toString()) {
                            myRecyclerViewAdapter.add(1, newName, newQty, newPCode, newPlant);
                        } else {
                            Toast.makeText(getApplicationContext(), "Product Already in the List", Toast.LENGTH_SHORT).show();
                        }
                    } else {
                        myRecyclerViewAdapter.add(0, newName, newQty, newPCode, newPlant);
                        }
                } else {
                    Toast.makeText(getApplicationContext(), "Invalied Item!", Toast.LENGTH_SHORT).show();
                }
                acTextView.setText("");
            }
        });


    }

如果我在此行中将位置更改为 1 if（newName！= myRecyclerViewAdapter.getItemName（position）.toString（））

LogCat给我这个错误

04-06 16:08:01.681 25361-25361/com.ceatkelanisrilanka.dushanmadushanka.ceat E/AndroidRuntime: FATAL EXCEPTION: main
                                                                                              Process: com.ceatkelanisrilanka.dushanmadushanka.ceat, PID: 25361
                                                                                              java.lang.IndexOutOfBoundsException: Invalid index 1, size is 1
                                                                                                  at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
                                                                                                  at java.util.ArrayList.get(ArrayList.java:308)
                                                                                                  at com.ceatkelanisrilanka.dushanmadushanka.ceat.adapters.SelectItemAdapter.getItemName(SelectItemAdapter.java:54)
                                                                                                  at com.ceatkelanisrilanka.dushanmadushanka.ceat.SelectItem$2.onItemClick(SelectItem.java:166)
                                                                                                  at android.widget.AutoCompleteTextView.performCompletion(AutoCompleteTextView.java:905)
                                                                                                  at android.widget.AutoCompleteTextView.access$500(AutoCompleteTextView.java:90)
                                                                                                  at android.widget.AutoCompleteTextView$DropDownItemClickListener.onItemClick(AutoCompleteTextView.java:1201)
                                                                                                  at android.widget.AdapterView.performItemClick(AdapterView.java:305)
                                                                                                  at android.widget.AbsListView.performItemClick(AbsListView.java:1146)
                                                                                                  at android.widget.AbsListView$PerformClick.run(AbsListView.java:3053)
                                                                                                  at android.widget.AbsListView$3.run(AbsListView.java:3860)
                                                                                                  at android.os.Handler.handleCallback(Handler.java:739)
                                                                                                  at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                                  at android.os.Looper.loop(Looper.java:135)
                                                                                                  at android.app.ActivityThread.main(ActivityThread.java:5254)
                                                                                                  at java.lang.reflect.Method.invoke(Native Method)
                                                                                                  at java.lang.reflect.Method.invoke(Method.java:372)
                                                                                                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
                                                                                                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

Answer 1

根据评论，如果您想检查RecyclerView中是否存在该项目，请尝试这样做：

if (myRecyclerViewAdapter.getItemCount() > 0) {
    if (!isPresent(newName, myRecyclerViewAdapter)) {
        myRecyclerViewAdapter.add(1, newName, newQty, newPCode, newPlant);
    } else {
        Toast.makeText(getApplicationContext(), "Product Already in the List", Toast.LENGTH_SHORT).show();
    }
}

isPresent可以像这样定义：

private boolean isPresent(String name, MyRecyclerViewAdapter myRecyclerViewAdapter){
    boolean isPresent = false;
    for(int i = 0; i < myRecyclerViewAdapter.getItemCount(); i++){
            if(name.equalsIgnoreCase(myRecyclerViewAdapter.getItemName(i).toString())){
                isPresent = true;
                break;
            }
    }
    return isPresent;
}

检查从RecyclerView中已存在的AutoCompleteTextView中选择的项目

1 个答案: