在 Spinner View Android 中显示最后的项目

Question

我正在尝试从数组中填充微调器。一切正常，但是当我单击微调器时，视图会将我带到数组的最后一项。所以我需要向上滚动才能看到第一项。

我想从头而不是从尾获得视图。请查看我的代码。我在 XML 中使用了 android:spinnerMode = "dialog"。

我的 spinner1 显示视图中的最后一项，但所有项都按正确的顺序排列。

public class Pinbyplace extends AppCompatActivity {

Spinner spinner1, spinner2, spinner3;
ArrayAdapter<String> adapter1, adapter2, adapter3;

public String[] state = {"Andaman and Nicobar Islands", "Andhra Pradesh", "Arunachal Pradesh", "Assam",
        "Bihar", "Chandigarh", "Chhattisgarh", "Dadar and Nagar Haveli",
        "Daman and Diu", "Delhi", "Goa", "Gujarat", "Haryana", "Himachal Pradesh",
        "Jammu and Kashmir", "Jharkhand", "Karnataka", "Kerala", "Lakshadeep",
        "Madya Pradesh", "Maharashtra", "Manipur", "Meghalaya", "Mizoram", "Nagaland",
        "Odhisa", "Pondicherry","Punjab", "Rajasthan", "Sikkim", "Tamil Nadu",enter code here
        "Tripura", "Uttaranchal", "Uttar Pradesh", "West Bengal", "Select State"};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.pincode_place);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setDisplayShowHomeEnabled(true);
    getSupportActionBar().setHomeButtonEnabled(true);
    toolbar.setNavigationOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            onBackPressed();
        }
    });

    spinner1 = (Spinner) findViewById(R.id.spinner1);
    spinner2 = (Spinner) findViewById(R.id.spinner2);
    spinner3 = (Spinner) findViewById(R.id.spinner3);

    adapter1 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, state) {
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View v = super.getView(position, convertView, parent);
            if (position == getCount()) {
                ((TextView)v.findViewById(android.R.id.text1)).setText("");
                ((TextView)v.findViewById(android.R.id.text1)).setHint(getItem(getCount()));
            }
            return v;
        }

        @Override
        public int getCount() {
            return super.getCount()-1;
        }
    };

    //adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner1.setAdapter(adapter1);
    spinner1.setSelection(adapter1.getCount());

    adapter2 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item) {
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View v = super.getView(position, convertView, parent);
            if (position == getCount()) {
                ((TextView)v.findViewById(android.R.id.text1)).setText("");
                ((TextView)v.findViewById(android.R.id.text1)).setHint(getItem(getCount()));
            }
            return v;
        }

        @Override
        public int getCount() {
            return super.getCount() - 1;
        }
    };

    adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    adapter2.add("Item 1");
    adapter2.add("Item 2");
    adapter2.add("Select District");

    spinner2.setAdapter(adapter2);
    spinner2.setSelection(adapter2.getCount());

    adapter3 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item) {
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View v = super.getView(position, convertView, parent);
            if (position == getCount()) {
                ((TextView)v.findViewById(android.R.id.text1)).setText("");
                ((TextView)v.findViewById(android.R.id.text1)).setHint(getItem(getCount()));
            }
            return v;
        }

        @Override
        public int getCount() {
            return super.getCount()-1;
        }
    };

    adapter3.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    adapter3.add("Item 1");
    adapter3.add("Item 2");
    adapter3.add("Select Place");

    spinner3.setAdapter(adapter3);
    spinner3.setSelection(adapter3.getCount());

}
 }

见下图：

更新：我为此找到了一个更好、更简单的解决方案..

public class Pinbyplace extends AppCompatActivity {

Spinner spinner_state, spinner_district, spinner_place;
HintArrayAdapter hintAdapter_state, hintAdapter_district, hintAdapter_place;

public String[] state = {"Select State", "Andaman and Nicobar Islands","Andhra Pradesh",
        "Arunachal Pradesh","Assam","Bihar", "Chandigarh","Chhattisgarh",
        "Dadra and Nagar Haveli","Daman and Diu","Delhi", "Goa","Gujarat","Haryana",
        "Himachal Pradesh","Jammu and Kashmir","Jharkhand", "Karnataka","Kerala",
        "Lakshadweep","Madhya Pradesh","Maharashtra","Manipur", "Meghalaya","Mizoram",
        "Nagaland","Odisha","Puducherry","Punjab","Rajasthan", "Sikkim","Tamil Nadu",
        "Telangana","Tripura","Uttar Pradesh","Uttarakhand","West Bengal"};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.pincode_place);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setDisplayShowHomeEnabled(true);
    getSupportActionBar().setHomeButtonEnabled(true);
    toolbar.setNavigationOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            onBackPressed();
        }
    });

    spinner_state = (Spinner) findViewById(R.id.spinner1);
    spinner_district = (Spinner) findViewById(R.id.spinner2);
    spinner_place = (Spinner) findViewById(R.id.spinner3);

    hintAdapter_state = new HintArrayAdapter<>(getApplicationContext(), 0);
    hintAdapter_state.addAll(state);
    spinner_state.setAdapter(hintAdapter_state);

    spinner_state.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            if(position > 0) {
                spinner_state.setSelection(position);
                String state_name = (String) spinner_state.getSelectedItem();
                Toast.makeText(getApplication(), state_name, Toast.LENGTH_SHORT).show();
            }
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {

        }
    });

    hintAdapter_district = new HintArrayAdapter<>(getApplicationContext(), 0);
    hintAdapter_district.add("Select Distrcit");
    spinner_district.setAdapter(hintAdapter_district);

    spinner_district.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            if(position > 0) {
                spinner_district.setSelection(position);
                String district_name = (String) spinner_district.getSelectedItem();
                Toast.makeText(getApplication(), district_name, Toast.LENGTH_SHORT).show();
            }
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {

        }
    });

    hintAdapter_place = new HintArrayAdapter<>(getApplicationContext(), 0);
    hintAdapter_place.add("Select Place");
    spinner_place.setAdapter(hintAdapter_place);

    spinner_place.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            if(position > 0) {
                spinner_place.setSelection(position);
                String place_name = (String) spinner_place.getSelectedItem();
                Toast.makeText(getApplication(), place_name, Toast.LENGTH_SHORT).show();
            }
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {

        }
    });
}

private class HintArrayAdapter<T> extends ArrayAdapter<T> {

    Context mContext;

    public HintArrayAdapter(Context context, int resource) {
        super(context, resource);
        this.mContext = context;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        View view = inflater.inflate(android.R.layout.simple_spinner_dropdown_item, parent, false);
        TextView texview = (TextView) view.findViewById(android.R.id.text1);
        texview.setTextColor(Color.BLACK);
        texview.setHintTextColor(Color.GRAY);

        if(position == 0) {
            texview.setText("");
            texview.setHint(getItem(position).toString()); //"Hint to be displayed"
        } else {
            texview.setText(getItem(position).toString());
        }

        return view;
    }

    @Override
    public View getDropDownView(int position, View convertView, ViewGroup parent) {

        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        View view;

        if(position == 0){
            view = inflater.inflate(R.layout.spinner_hint_list_item_layout, parent, false); // Hide first row
        } else {
            view = inflater.inflate(android.R.layout.simple_spinner_dropdown_item, parent, false);
            TextView texview = (TextView) view.findViewById(android.R.id.text1);
            texview.setTextColor(Color.BLACK);
            texview.setText(getItem(position).toString());
        }

        return view;
    }
}
}

Answer 1

 adapter3.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    adapter3.add("Item 1");
    adapter3.add("Item 2");
    adapter3.add("Select Place");

    spinner3.setAdapter(adapter3);
    spinner3.setSelection(adapter3.getCount());

改成

spinner3.setSelection(0);

因为 spinner3.setSelection(adapter3.getCount());表示 Spinner Postion 是您的数组大小。所以 Spinner Goto Last Index ......

Answer 2

尝试评论这些行

spinner.setSelection()

它的作用是在你的微调器中设置选定的项目。

这里你写的像

spinner.setSelection(adapter.getCount())

所以它正在选择最后一项。

编辑

通过这个链接，可以发布整个代码，但这似乎是多余的，

https://stackoverflow.com/a/27692614/2641726

在 CustomSpinner 类中，在 'performClick()' 方法中，将选择设置为 0，如下所示

this.setSelection(0)

但是您必须管理状态并相应地工作，是的，在您的 xml 布局文件中将 Spinner 替换为 CustomSpinner。

Answer 3

很抱歉，以上都不适合我。 但是 spinner.setSelection(adapter.getCount()-1) 对我有用 由于 getCount() 是大小，我们必须减去 1 才能将其转换为索引。否则只会 OutofBound 异常。

谢谢。