我有三个微调器，第一个是从字符串xml文件中填充的，第二个应根据第一个和第三个的选择填充，基于第二个选择。
我在周末搜索并尝试了几种逻辑但没有成功。在第二个和第三个微调器上设置setOnItemSelectedListener后，它们都不会被填充。
请帮帮我。示例代码在下面提供
public class Reg_Prop extends Activity implements AdapterView.OnItemSelectedListener {
//create reference
Button btnSave;
Spinner spinProvince, spinDistrict, spinLocal;
String spinPro, spinDist;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_reg_prop);
Toast.makeText(this, "Please select the Province, District and Local Municipality where the " +
"Property is located", Toast.LENGTH_LONG).show();
//Initialise reference
btnSave = (Button)findViewById(R.id.btnSave);
spinProvince = (Spinner)findViewById(R.id.spinProvince);
spinDistrict=(Spinner)findViewById(R.id.spinDistrict);
spinLocal=(Spinner)findViewById(R.id.spinLocal);
//set onClick Listener
btnSave.setOnClickListener(new View.OnClickListener() {
//@Overridde
public void onClick(View v) {
try {
Intent ro = new Intent(getApplicationContext(), MainActivity.class);
startActivity(ro);
//Toast.makeText(getApplicationContext(), "Login button pressed", Toast.LENGTH_LONG).show();
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "Login window could not display",
Toast.LENGTH_LONG).show();
e.printStackTrace();
}
}
});
//set onItemSelected Listener
spinProvince.setOnItemSelectedListener(this);
spinDistrict.setOnItemSelectedListener(this);
}
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
switch (view.getId()){
case R.id.spinProvince:
spinPro = String.valueOf(spinProvince.getSelectedItem());
Toast.makeText(this, spinPro, Toast.LENGTH_SHORT).show();
if(spinPro.contentEquals("Eastern Cape")){
List<String> list = new ArrayList<String>();
list.add("Select District/Metro *");
list.add("Buffalo City");
list.add("Nelson Mandela Bay");
list.add("Alfred Nzo District");
list.add("Amathole District");
list.add("Chris Hani District");
list.add("Joe Gqabi District");
list.add("OR Tambo District");
list.add("Cacadu District");
final ArrayAdapter<String> districtAdapter = new ArrayAdapter<>(this,
android.R.layout.simple_spinner_item, list);
districtAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
districtAdapter.notifyDataSetChanged();
spinDistrict.setAdapter(districtAdapter);
}
}
else{
Toast.makeText(this, "Please select the Province where the Property is located", Toast.LENGTH_LONG).show();
}
break;
case R.id.spinDistrict:
spinDist = spinDistrict.getSelectedItem().toString();
if(spinDist != "" && spinDist != "Select District/Metro *" || spinDist != "Select District *"){
switch (spinDist){
case "Buffalo City":
List<String> list = new ArrayList<String>();
list.add("Select District/Metro *");
list.add("...");
list.add("N....");
list.add("Local");
list.add("Amathole District");
list.add("Chris Hani District");
list.add("Joe Gqabi District");
list.add("OR Tambo District");
list.add("Cacadu District");
final ArrayAdapter<String> localAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, list);
localAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
localAdapter.notifyDataSetChanged();
spinLocal.setAdapter(localAdapter);
break;
}
}
else{
Toast.makeText(this, "Please select the District Municipality", Toast.LENGTH_LONG).show();
}
break;
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
Toast.makeText(this, "Please select the Province, District and Local Municipality where the Property is located", Toast.LENGTH_LONG).show();
}
答案 0 :(得分：0)
感谢所有阅读并试图帮助我的人。我终于解决了这个问题。
我所要做的就是为onCreate中的前两个微调器放置setOnItemSelectedListener，然后使用函数根据选择填充第二个和第三个微调器。注意：第一个微调器是从字符串xml文件中填充的。
以下是示例代码 在onCreate里面：
//set onItemSelected Listener
spinProvince.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
String province = (String)parent.getItemAtPosition(position);
if(province.matches("Eastern Cape")){
spinPro = 1;
populateDist();
}
else if(province.matches("Free State")){
spinPro = 2;
populateDist();
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
Toast.makeText(Reg_Prop.this, "Please select the Province where the Property is located", Toast.LENGTH_LONG).show();
}
});
spinDistrict.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener(){
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
String spinDist = (String)parent.getItemAtPosition(position);
if(spinDist.matches("Buffalo City") && spinPro == 1){
dist = 1;
populateLocal();
}
else if(spinDist.matches("Nelson Mandela Bay") && spinPro == 1){
dist = 2;
populateLocal();
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
填充微调器的功能
void populateDist(){
//Eatern Cape
if(spinPro == 1){
String [] ec = {"Select District/Metro *", "Buffalo City", "Nelson Mandela Bay",
"Alfred Nzo District", "Amathole District", "Chris Hani District",
"Joe Gqabi District", "OR Tambo District", "Cacadu District"};
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, ec);
spinDistrict.setAdapter(adapter);
}
//Free State
else if(spinPro == 2){
String [] fs = {"Select District/Metro *", "Mangaung Metropolitan", "Fezile Dabi District",
"Lejweleputswa District", "Thabo Mofutsanyana District", "Xhariep District"};
ArrayAdapter<String> adapter2 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, fs);
spinDistrict.setAdapter(adapter2);
}
}
void populateLocal(){
//Baffalo City
if(dist == 1){
String [] bc = {"Buffalo City"};
ArrayAdapter<String> adapterL1 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, bc);
spinLocal.setAdapter(adapterL1);
}
//Nelson Mandela Bay
else if(dist == 2){
String [] nmb = {"Nelson Mandela Bay"};
ArrayAdapter<String> adapterL2 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, nmb);
spinLocal.setAdapter(adapterL2);
}
}