在android中使用依赖微调器（多个微调器）的问题

Question

我正在尝试从前一个微调器中填充下一个微调器的值。在这种情况下，我所做的是在微调器中生成所有值，这意味着，无论我在前一个微调器中选择哪个值，它始终会在下一个微调器中显示所有值。我正在使用五个微调器，它们需要根据前一个来填充值。在这里，我使用微调器的库。库如下。

'com.toptoche.searchablespinner:searchablespinnerlibrary:1.3.1'

在这里，我将分享我的整个代码/类以供您参考。没有错误，我在各自的微调器中获取所有值，但我想根据前一个获取值。这是我的代码。

import androidx.appcompat.app.AppCompatActivity;
import com.toptoche.searchablespinnerlibrary.SearchableSpinner;

public class Catchment extends AppCompatActivity implements AdapterView.OnItemSelectedListener {

public ArrayAdapter<String> regionAdapter;
public ArrayAdapter<String> districtAdapter;
public ArrayAdapter<String> upzAdapter;
public ArrayAdapter<String> unionAdapter;
public ArrayAdapter<String> villageAdapter;
public String[] Region = {"1", "2",
};
public String[] District = {"1","2","3","4","5","6","7","8",};
public String[] Upz = {"1","2"...."23";
public String[] Union = {"1","2"...."25"..."50"...."115"};
public String[] Village = { "1","2"...."25"..."50"...."150"...."500"...."947"   };
Button catchment_code;
SearchableSpinner spinner_region, spinner_district, spinner_upz, spinner_union, spinner_village;
String[] region_code;
String[] district_code;
String[] upz_code;
String[] union_code;
String[] vill_code;
int positions;
String test;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_catchment);

    spinner_region = (SearchableSpinner) findViewById(R.id.region);
    spinner_district = (SearchableSpinner) findViewById(R.id.district);
    spinner_upz = (SearchableSpinner) findViewById(R.id.upz);
    spinner_union = (SearchableSpinner) findViewById(R.id.union);
    spinner_village = (SearchableSpinner) findViewById(R.id.village);

    catchment_code = findViewById(R.id.catchment_code);


    // Set spninner adapter
    regionAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, Region);
    districtAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, District);
    upzAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, Upz);
    unionAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, Union);
    villageAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, Village);

    //Set dropdown to the spinner
    regionAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    districtAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    upzAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    unionAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    villageAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    //assign to spinner
    spinner_region.setAdapter(regionAdapter);
    spinner_district.setAdapter(districtAdapter);
    spinner_upz.setAdapter(upzAdapter);
    spinner_union.setAdapter(unionAdapter);
    spinner_village.setAdapter(villageAdapter);

    spinner_region.setOnItemSelectedListener(this);
    spinner_district.setOnItemSelectedListener(this);
    spinner_upz.setOnItemSelectedListener(this);
    spinner_union.setOnItemSelectedListener(this);
    spinner_village.setOnItemSelectedListener(this);
}

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

    if (parent.getId() == R.id.region) {
        positions = spinner_region.getSelectedItemPosition();
        region_code = this.getResources().getStringArray(R.array.region_code);
        //Toast.makeText(this, region_code[positions], Toast.LENGTH_SHORT).show();
    }
    if (parent.getId() == R.id.district) {
        positions = spinner_district.getSelectedItemPosition();
        district_code = this.getResources().getStringArray(R.array.district_code);
        //Toast.makeText(this, district_code[positions], Toast.LENGTH_SHORT).show();
    }
    if (parent.getId() == R.id.upz) {
        positions = spinner_upz.getSelectedItemPosition();
        upz_code = this.getResources().getStringArray(R.array.upz_code);
        //Toast.makeText(this, upz_code[positions], Toast.LENGTH_SHORT).show();
    }
    if (parent.getId() == R.id.village) {
        positions = spinner_village.getSelectedItemPosition();
        vill_code = this.getResources().getStringArray(R.array.village_code);
        //Toast.makeText(this, vill_code[positions], Toast.LENGTH_LONG).show();
    }
    if (parent.getId() == R.id.union) {
        positions = spinner_union.getSelectedItemPosition();
        union_code = this.getResources().getStringArray(R.array.union_code);
        //Toast.makeText(this, union_code[positions], Toast.LENGTH_SHORT).show();
    }
    if (!(vill_code == null || region_code == null || district_code == null || upz_code == null ||
            union_code == null)) {
        test = region_code[positions] +
                district_code[positions] +
                upz_code[positions] +
                union_code[positions] + vill_code[positions];
        Toast.makeText(this, test, Toast.LENGTH_SHORT).show();
    }
    catchment_code.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            Intent intent = new Intent(Catchment.this, Participant_Details.class);
            intent.putExtra("catment_code", test);
            startActivity(intent);


        }
    });

    //Toast.makeText(this, union_code[positions]+upz_code[positions], Toast.LENGTH_SHORT).show();
}

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

@Override
public void onBackPressed() {
    Intent intent = new Intent(Catchment.this, SplashScreen.class);
    Catchment.this.startActivity(intent);
    Catchment.this.finish();}
}

那么我怎样才能摆脱这个问题呢？我需要帮助。

Answer 1

您在 onCreate() 中一次声明所有适配器。

而是在 onCreate() 中只声明第一个适配器并使用空值声明其他适配器。

        @Override
    protected void onCreate(Bundle savedInstanceState) {
     --------;
     // Set spninner adapter
        regionAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, Region);
        districtAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, new String[]());
        upzAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, new String[]());
        unionAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, new String[]());
        villageAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, new String[]());

------
       spinner_region.setOnItemSelectedListener(this);
}

现在在 itemSelectedListener 上，如果需要，过滤所需的值并将值添加到下一个所需的适配器并通知值以及将侦听器添加到下一个微调器（添加侦听器取决于您，您希望如何处理这些事情）

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
      if (parent.getId() == R.id.region) {
     positions = spinner_region.getSelectedItemPosition();
     String[] filteredDistrict = District.filter(Region[position]) // District.filter is not any predefined function, assuming some filter needed for selected Districts
     districtAdapter.addValues(filteredDistrict);
     districtAdapter.notifyDataSetChanged()
     spinner_district.setOnItemSelectedListener(this);
}
}

除此之外的过滤逻辑取决于您的用例。