具有動態數組列表的 AutoCompletetextview

Question

嗨，我剛開始學習 android Studio，如果用戶輸入未在數組列表中列出，我想要一個AutoCompletetextView和一個添加用戶輸入的按鈕。我的AutoCompleteTextView完全有效，但我無法通過 onClick 監聽器。任何幫助都可以贊賞。

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private AutoCompleteTextView actv;
    private Button btn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn = findViewById(R.id.btn);
        actv = findViewById(R.id.actv);
        actv.setThreshold(1);

        String[] color = {"blue", "brown", "black", "red", "green", "gray", "violet", "white", "orange"};
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, color);
        actv.setAdapter(adapter);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

            }
        });




    }
}

和 xml

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">

<TextView
    android:id="@+id/textView"
    android:layout_width="100dp"
    android:layout_height="32dp"
    android:layout_marginStart="152dp"
    android:layout_marginLeft="152dp"
    android:layout_marginTop="280dp"
    android:text="Hello World!"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

<AutoCompleteTextView
    android:id="@+id/actv"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="204dp"
    android:gravity="center"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

<Button
    android:id="@+id/btn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="160dp"
    android:layout_marginLeft="160dp"
    android:layout_marginTop="12dp"
    android:text="Add"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/textView" />

Answer 1

代替

    String[] color = {"blue", "brown", "black", "red", "green", "gray", "violet", "white", "orange"};
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, color);
    actv.setAdapter(adapter);
    btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

        }
    });

和

final List<String> colorList = new ArrayList<>();
colorList.add("blue");
colorList.add("green");

ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, colorList);
actv.setAdapter(adapter);
btn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
       String text = actv.getText().toString();
       int size = colorList.size();
        boolean exists = false;
       for(int i=0;i<size;i++){
           if(colorList.get(i).equals(text)){
              exists = true;
           } 
       }
       if(exists==false){
         colorList.add(text);
         ArrayAdapter newAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, colorList);
         actv.setAdapter(adapter);
       }
    }
});

Answer 2

您應該使用ArrayList而不是String[]

這是單擊按鈕時我們如何將項目添加到 ArrayList 的代碼

ArrayList<String> color1 = new ArrayList<>();
color1.add("blue");
color1.add("brown");
color1.add("black");
color1.add("red");
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, color1);
actv.setThreshold(1);
actv.setAdapter(adapter);

btn.setOnClickListener(new View.OnClickListener() {
     @Override
     public void onClick(View v) {
         String s = String.valueOf(actv.getText());
         adapter.add(s); //Add Item in Adapter
    }
});