什么是Android的正确的方式实现开关case语句？ [解决了] [英] What is the correct way implement switch case statement in Android? [SOLVED]
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问题描述
它并没有出现任何错误。但是当我跑我的应用程序，也没有结果，从我的ListView出现。我认为，这个错误是因为我没有用正确的方法做开关case语句。这里是我的code。
It didn't showing up any error. however when I run my application, there is no result appear from my listView. I think,the mistake is because of i didn't use the correct way doing switch case statement. here is my code.
QuickSearch.java
QuickSearch.java
package com.example.awesome;
import java.io.IOException;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.database.SQLException;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class QuickSearch extends Activity implements OnClickListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
//-------------------------------------------------------------------------
// Initiate database data
initiateDb();
//---------------------------------------------------------------------------
// Declaration of view
final Button qsfaculty, qscollege;
super.onCreate(savedInstanceState);
setContentView(R.layout.quick_search);
//---------------------------------------------------------------------------
// Get reference
qsfaculty = (Button) this.findViewById(R.id.button1);
qsfaculty.setOnClickListener(this);
qscollege = (Button) this.findViewById(R.id.button2);
qscollege.setOnClickListener(this);
}
public void onClick(View v) {
char ch = 0;
View qsfaculty = null;
View qscollege = null;
if(v == qsfaculty){
ch = 'a';
}
else if (v == qscollege)
{ch = 'b';}
Intent i = new Intent(this,SearchLocation.class);
i.putExtra("value",ch);
startActivity(i);
}
//---------------------------------------------------------------------------
// Initiate database data
public void initiateDb() {
DatabaseHandler myDbHandler = new DatabaseHandler(this);
try {
myDbHandler.createDataBase();
}
catch (IOException ioe) {
throw new Error("Unable to create database");
}
try {
myDbHandler.openDataBase();
}
catch(SQLException sqle) {
throw sqle;
}
Log.d("Initiate", "UKM Location Count: " + myDbHandler.getUkmLocationCount());
myDbHandler.close();
}
//------------------------------------------------------------------------------
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.quick_search, menu);
return true;
}
}
SearchLocation.java
SearchLocation.java
package com.example.awesome;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.app.Activity;
import android.app.ListActivity;
import android.content.Intent;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
public class SearchLocation extends ListActivity {
//------------------------------------------------------------------
// Declaration
public static UkmLocation selectedPOI = null;
final DatabaseHandler db = new DatabaseHandler(this);
private EditText filterText = null;
ArrayAdapter<String> adapter = null;
final ArrayList<String> results = new ArrayList<String>();
final ArrayList<String> results_id = new ArrayList<String>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.search_location);
final Intent c = new Intent(SearchLocation.this, LocationDetail.class);
//------------------------------------------------------------------
// Link editText to layout item
filterText = (EditText) findViewById(R.id.search_box);
filterText.addTextChangedListener(filterTextWatcher);
//------------------------------------------------------------------
// Reading Poi
Log.d("Reading", "Reading all Kategori ..");
int value = 0;
switch(value) {
case 'a' :
List<UkmLocation> faculty = db.getCategoryFaculty();
for(UkmLocation k : faculty) {
results.add(k.getName());
results_id.add(k.getID());
}
break;
case 'b' :
List<UkmLocation> college = db.getCategoryCollege();
for(UkmLocation k : college) {
results.add(k.getName());
results_id.add(k.getID());
}
break;
}
//------------------------------------------------------------------
// Set list arrayAdapter to adapter
adapter = new ArrayAdapter<String>(this, R.layout.list_item, R.id.textView1,results);
setListAdapter(adapter);
//------------------------------------------------------------------
// Set ListView from ListActivity
ListView lv = getListView();
lv.setTextFilterEnabled(true);
//------------------------------------------------------------------
// Set click event from listView
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// When clicked, show a toast with the TextView text
Toast.makeText(getApplicationContext(), ((TextView) view).getText(),
Toast.LENGTH_SHORT).show();
Log.d("test", "position:" + position);
Log.d("test", "actualname:" + db.getUkmLocationByName(adapter.getItem(position)).getName());
// String poiID = results_id.get(position);
String poiID = db.getUkmLocationByName(adapter.getItem(position)).getID();
setSelectedPoi(poiID);
startActivity(c);
}
});
}
private TextWatcher filterTextWatcher = new TextWatcher() {
public void afterTextChanged(Editable s) {
}
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
}
public void onTextChanged(CharSequence s, int start, int before,
int count) {
adapter.getFilter().filter(s);
}
};
@Override
protected void onDestroy() {
super.onDestroy();
filterText.removeTextChangedListener(filterTextWatcher);
}
public UkmLocation getSelectedPoi() {
return selectedPOI;
}
public void setSelectedPoi(String poiID) {
selectedPOI = db.getUkmLocation(poiID);
Log.d("test2", "_id:" + db.getUkmLocation(poiID).getID());
Log.d("test2", "Name:" + db.getUkmLocation(poiID).getName());
// Closing db
db.close();
}
}
我想，里面QuickSearch.java的if else语句已经是正确的。在在SearchLocation.java开关case语句的问题
请帮我解决这个问题。
i think,the if else statement inside QuickSearch.java is already correct. the problem at the switch case statement at SearchLocation.java please help me solve this.
推荐答案
在这里，我已经解决我的问题。
here, i already solve my problem..
QuickSearch.java
public void onClick(View v) {
int ch = 0;
/*View qsfaculty = null;
View qscollege = null;*/
if(v == qsfaculty){
ch = '1';
}
else if (v == qscollege)
{ch = '2';}
Intent i = new Intent(this,SearchLocation.class);
i.putExtra("value",ch);
startActivity(i);
}
SearchLocation.java
Bundle extras = getIntent().getExtras();
int value = extras.getInt("value");
switch(value) {
case '1' :
List<UkmLocation> faculty = db.getCategoryFaculty();
for(UkmLocation k : faculty) {
results.add(k.getName());
results_id.add(k.getID());
}
break;
case '2' :
List<UkmLocation> college = db.getCategoryCollege();
for(UkmLocation k : college) {
results.add(k.getName());
results_id.add(k.getID());
}
break;
}
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