Android 如何使用微调器
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how to use spinner
提问by corotana
I am very new to android. I want to use 2 spinners in my application, one shows the countries list, when any country is selected the other spinner should show the list of cities of that country. when city is selected some action is performed. plz help me with some sample code. thanks in anticipation
我对android很陌生。I want to use 2 spinners in my application, one shows the countries list, when any country is selected the other spinner should show the list of cities of that country. 选择城市时，会执行一些操作。请帮我一些示例代码。感谢期待
回答by Harpreet
Here is something what we can use to add options to spinner2 w.r.t to spinner 1.
这是我们可以用来将选项添加到 spinner2 wrt 到 spinner 1 的东西。
public class Activity extends Activity implements View.OnClickListener
{
private Spinner spinner0, spinner1, spinner2, spinner3;
private Button submit, cancel;
private String country[], state[], city[], area[];
Australia aus = new Australia();
Object object;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
spinner0 = (Spinner)findViewById(R.id.spinnerCountry);
spinner1 = (Spinner)findViewById(R.id.spinnerQ1);
spinner2 = (Spinner)findViewById(R.id.spinnerQ2);
spinner3 = (Spinner)findViewById(R.id.spinnerQ3);
submit = (Button)findViewById(R.id.btnSubmit);
cancel = (Button)findViewById(R.id.btnCancel);
submit.setOnClickListener(this);
cancel.setOnClickListener(this);
country = new String[] {"Select Country", "Australia", "USA", "UK", "New Zealand", "EU", "Europe", "China", "Hong Kong",
"India", "Malaysia", "Canada", "International", "Asia", "Africa"};
ArrayAdapter<String> adapter0 = new ArrayAdapter<String>(Activity.this, android.R.layout.simple_spinner_item, country);
adapter0.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
spinner0.setAdapter(adapter0);
Log.i("AAA","spinner0");
spinner0.setOnItemSelectedListener(new OnItemSelectedListener()
{
@Override
public void onItemSelected(AdapterView<?> arg0, View view1, int pos, long id)
{
Log.i("AAA","OnItemSelected");
int loc;
loc = pos;
switch (loc)
{
case 1:
state = aus.getState();
object = aus;
Log.i("AAA","ArrayAdapter1");
ArrayAdapter<String> adapter1 = new ArrayAdapter<String>(Activity.this, android.R.layout.simple_spinner_item, state);
adapter1.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
spinner1.setAdapter(adapter1); Log.i("AAA","spinner1");
break;
default:
Log.i("AAA","default 0");
break;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg1)
{
Log.i("AAA","Nothing S0");
}
});
spinner1.setOnItemSelectedListener(new OnItemSelectedListener()
{
@Override
public void onItemSelected(AdapterView<?> arg0, View view1, int pos, long id)
{
Log.i("AAA","OnItemSelected S1");
int loc = pos;
switch(loc)
{
case 1:
Log.i("AAA","Australia");
if(object.equals(aus))
{
city = aus.getType(loc);
}
else
{
break;
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(Activity.this, android.R.layout.simple_spinner_item, city);
adapter.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
spinner2.setAdapter(adapter); Log.i("AAA","spinner2");
break;
default:
Log.i("AAA", "default 1");
break;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0)
{
Log.i("AAA","Nothing S1");
}
});
spinner2.setOnItemSelectedListener(new OnItemSelectedListener()
{
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int pos, long id)
{
int loc = pos;
switch (loc)
{
case 1:
if(object.equals(aus))
{
area = aus.getTitle(loc);
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(Activity.this, android.R.layout.simple_spinner_item, area);
adapter.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
spinner3.setAdapter(adapter); Log.i("","spinner3");
break;
default:
break;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0)
{
// TODO Auto-generated method stub
}
});
}// on-create
@Override
public void onClick(View v)
{
switch (v.getId())
{
case R.id.btnSubmit:
break;
case R.id.btnCancel:
finish();
break;
default:
break;
}
}
}
If you find this useful, then do give it up vote, so that others can find a good answer easily.
如果你觉得这很有用，那就放弃投票吧，这样其他人就可以轻松找到好的答案。
For each Country, you have to create a class for it, to just add State, City & Area. So that it doesn't become a mesh at a single at single page.
对于每个国家，您必须为其创建一个类，只需添加州、城市和地区。这样它就不会在单个页面上变成一个网格。
Have fun.
玩得开心。
Regards,
问候，
Haps.
哈。
回答by Rachita Nanda
Here is a sample code which depicts the usage of spinner and action performed when spinner item is selected
这是一个示例代码，描述了选择微调项时微调器的使用和执行的操作
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.AdapterView.OnItemSelectedListener;
public class MainActivity extends Activity {
Spinner spin;
String spin_val;
String[] gender = { "Male", "Female" };//array of strings used to populate the spinner
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);//setting layout
spin = (Spinner) findViewById(R.id.spinner_id);//fetching view's id
//Register a callback to be invoked when an item in this AdapterView has been selected
spin.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1,
int position, long id) {
// TODO Auto-generated method stub
spin_val = gender[position];//saving the value selected
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
});
//setting array adaptors to spinners
//ArrayAdapter is a BaseAdapter that is backed by an array of arbitrary objects
ArrayAdapter<String> spin_adapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_spinner_item, gender);
// setting adapteers to spinners
spin.setAdapter(spin_adapter);
}
}
To add a list of values to the spinner, you then need to specify a SpinnerAdapter in your Activity, which extends Adapter class.. A spinner adapter allows to define two different views: one that shows the data in the spinner itself and one that shows the data in the drop down list when the spinner is pressed.You can also download & refer to the complete spinner_demoexample project for better understanding.
要将值列表添加到微调器，您需要在 Activity 中指定一个 SpinnerAdapter，它扩展了 Adapter 类。微调适配器允许定义两种不同的视图：一种显示微调器本身中的数据，另一种显示按下微调器时下拉列表中的数据。您也可以下载并参考完整的spinner_demo示例项目以更好地理解。
回答by Karan
回答by Android Coder
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
spinner = (Spinner)findViewById(R.id.spinner);
list = new ArrayList<String>();
list.add("Select your Favorite Color");
list.add("Blue");
list.add("White");
list.add("Red");
list.add("Green");
list.add("Black");
list.add("Yellow");
list.add("Pink");
list.add("Orange");
SpinnerAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,list){
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = super.getView(position, convertView, parent);
// set the textColor you want
return v;
}
@Override
public View getDropDownView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
View v = super.getDropDownView(position, convertView, parent);
// Set the BackgroundColor
return v;
}
};
SpinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(SpinnerAdapter);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
String state = adapterView.getItemAtPosition(i).toString();
}
@Override
public void onNothingSelected(AdapterView<?> adapterView) {
}
});
}
}
}
