我必须开发一个
android视图,这样我就有2个微调控件,一个用于州,第二个用于城市.
我的问题是,无论何时选择州,我如何自动填充城市微调器？
它背后的逻辑是什么？
我的string.xml：
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="spinner_category"></string>
<string-array name="category_state">
<item >kerala</item>
<item >tamil nadu</item>
<item >Andra Pradesh</item>
<item >karnataka</item>
</string-array>
</resources>
我的main.xml：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<LinearLayout android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="10dip"
android:text="Select : "/>
<Spinner android:layout_width="250dip"
android:layout_height="wrap_content"
android:id="@+id/spinner_state"/>
</LinearLayout>
<LinearLayout android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="10dip"
android:text="Select : "/>
<Spinner android:layout_width="250dip"
android:layout_height="wrap_content"
android:id="@+id/spinner_state"/>
</LinearLayout>
</LinearLayout>
还有我的activity.java文件：
package com.converter;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
public class ConverterActivity extends Activity
{
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Spinner spinner_s = (Spinner)findViewById(R.id.spinner_state);
ArrayAdapter<CharSequence> category_adapter = ArrayAdapter.createFromResource(
this,R.array.category_array,android.R.layout.simple_spinner_item);
category_adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner_s.setAdapter(category_adapter);
}
}
解决方法
例：
Spinner city=(Spinner)findViewById(R.id.citySpinner);
Spinner state=(Spinner)findViewById(R.id.stateSpinner);
final ArrayList<String> state_options=new ArrayList<String>();
final ArrayList<String> city_options=new ArrayList<String>();
state_options.add("state_1");
state_options.add("state_2");
state_options.add("state_3");
// Here you can also get a cursor and add Strings as options to state_options instead of what i have done
city_options.add("city_1_state_1");
city_options.add("city_2_state_1");
city_options.add("city_3_state_1");
// Here you can also get a cursor and add Strings as options to city_options instead of what i have done
ArrayAdapter<String> cityAdapter = new ArrayAdapter<String>(getApplicationContext(),android.R.layout.simple_spinner_item,city_options);
city.setAdapter(cityAdapter);
ArrayAdapter<String> stateAdapter = new ArrayAdapter<String>(getApplicationContext(),state_options);
state.setAdapter(stateAdapter);
state.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0,View view,int position,long id) {
String stateName=state_options.get(position).toString();
resetCity(stateName);
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
}
});
现在,
public void resetCity(String stateName)
{
city_options.removeAll(city_options);//i haven't checked this.
if(stateName.eqauls("state_1"))
{
city_option.add("city_1_state_1");
city_options.add("city_2_state_1");
city_options.add("city_3_state_1");
//you can also get a cursor and add Strings as options to city_options instead of what i have done
}
else if(stateName.eqauls("state_2"))
{
city_option.add("city_1_state_2");
city_options.add("city_2_state_2");
city_options.add("city_3_state_2");
// you can also get a cursor and add Strings as options to city_options instead of what i have done
}
else
{
city_option.add("city_1_state_3");
city_options.add("city_2_state_3");
city_options.add("city_3_state_3");
//you can also get a cursor and add Strings as options to city_options instead of what i have done
}
ArrayAdapter<String> cityAdapter = new ArrayAdapter<String>(getApplicationContext(),city_options);
city.setAdapter(cityAdapter);
}
这是最简单的示例.您可以从数据库中设置city_options和state_options.然后您可以使用它来填充accoring spinners.
