android java在不重新启动的情况下运行活动
我创建了一个简单的应用程序,可以登录到DB并从中获取数据。但是现在我发现了一个问题:如果你第一次写错了登录数据,然后第二次尝试登录,那么它将无法工作。你必须重新启动它 我认为这段代码有一个问题:已编辑android java在不重新启动的情况下运行活动,java,android,Java,Android,我创建了一个简单的应用程序,可以登录到DB并从中获取数据。但是现在我发现了一个问题:如果你第一次写错了登录数据,然后第二次尝试登录,那么它将无法工作。你必须重新启动它 我认为这段代码有一个问题:已编辑 public class MyMoodleApplicationActivity extends Activity { /** Called when the activity is first created. */ EditText username; EditText password; @
public class MyMoodleApplicationActivity extends Activity {
/** Called when the activity is first created. */
EditText username;
EditText password;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
username = (EditText)findViewById(R.id.username);
password = (EditText)findViewById(R.id.password);
final Button loginButton = (Button)findViewById(R.id.login);
loginButton.setOnClickListener(loginListener);
final Button clearButton = (Button)findViewById(R.id.clear);
clearButton.setOnClickListener(clearListener);
}
private OnClickListener loginListener = new OnClickListener(){
public void onClick(View v){
String usr = username.getText().toString();
String psw = password.getText().toString();
System.out.println("Username: "+usr);
System.out.println("Password: "+psw);
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("usern",""+usr));
nameValuePairs.add(new BasicNameValuePair("passw",""+psw));
InputStream is = null;
String result = "";
//http post
try{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://ik.su.lt/*****");
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
}catch(Exception e){
Log.e("log_tag", "Error in http connection "+e.toString());
}
//convert response to string
try{
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result=sb.toString();
}catch(Exception e){
Log.e("log_tag", "Error converting result "+e.toString());
}
String usernameFromDB = "";
String firstnameFromDB = "";
String lastnameFromDB = "";
String emailFromDB = "";
String phoneFromDB = "";
String skypeFromDB = "";
String cityFromDB = "";
String descriptionFromDB = "";
try{
JSONArray jArray = new JSONArray(result);
for(int i=0;i<jArray.length();i++){
JSONObject json_data = jArray.getJSONObject(i);
usernameFromDB = json_data.getString("username");
firstnameFromDB = json_data.getString("firstname");
lastnameFromDB = json_data.getString("lastname");
emailFromDB = json_data.getString("email");
phoneFromDB = json_data.getString("phone1");
skypeFromDB = json_data.getString("skype");
cityFromDB = json_data.getString("city");
descriptionFromDB = json_data.getString("description");
System.out.println(usernameFromDB+ " " + firstnameFromDB+" "+lastnameFromDB+" "
+ emailFromDB + " " + phoneFromDB +" " + skypeFromDB+ " " + cityFromDB + " "+
descriptionFromDB);
}
}
catch(JSONException e){
AlertDialog alertDialog = new AlertDialog.Builder(MyMoodleApplicationActivity.this).create();
alertDialog.setTitle("Klaida!");
alertDialog.setMessage("Toks vartotojas neegzistuoja");
alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
return;
}
});
alertDialog.show();
Log.e("log_tag", "Error parsing data "+e.toString());
}
if(usr.length()== 0){
AlertDialog alertDialog = new AlertDialog.Builder(MyMoodleApplicationActivity.this).create();
alertDialog.setTitle("Klaida!");
alertDialog.setMessage("Jūs neįvedėte slapyvardžio");
alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
return;
}
});
alertDialog.show();
}
else if(psw.length()==0){
AlertDialog alertDialog = new AlertDialog.Builder(MyMoodleApplicationActivity.this).create();
alertDialog.setTitle("Klaida!");
alertDialog.setMessage("Jūs neįvedėte slaptažodžio");
alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
return;
}
});
alertDialog.show();
}
else if (usr.equals(usernameFromDB)){
Intent in = new Intent(getApplicationContext(), LoggedUser.class);
in.putExtra("firstname", firstnameFromDB);
in.putExtra("lastname", lastnameFromDB);
in.putExtra("email", emailFromDB);
in.putExtra("phone1", phoneFromDB);
in.putExtra("skype", skypeFromDB);
in.putExtra("city", cityFromDB);
in.putExtra("description", descriptionFromDB);
startActivity(in);
finish();
}
}};
private OnClickListener clearListener = new OnClickListener(){
@Override
public void onClick(View v){
username.setText("");
password.setText("");
}
};
公共类MyMoodleApplicationActivity扩展活动{
/**在首次创建活动时调用*/
编辑文本用户名;
编辑文本密码;
@凌驾
创建时的公共void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
用户名=(EditText)findViewById(R.id.username);
密码=(EditText)findViewById(R.id.password);
最终按钮登录按钮=(按钮)findViewById(R.id.login);
setOnClickListener(loginListener);
最终按钮clearButton=(按钮)findViewById(R.id.clear);
clearButton.setOnClickListener(clearListener);
}
private OnClickListener loginListener=new OnClickListener(){
公共void onClick(视图v){
字符串usr=username.getText().toString();
字符串psw=password.getText().toString();
System.out.println(“用户名:+usr”);
System.out.println(“密码:+psw”);
ArrayList nameValuePairs=新的ArrayList();
添加(新的BasicNameValuePair(“usern”、“usr”);
添加(新的BasicNameValuePair(“passw”,即“+psw));
InputStream=null;
字符串结果=”;
//http post
试一试{
HttpClient HttpClient=新的DefaultHttpClient();
HttpPost HttpPost=新的HttpPost(“http://ik.su.lt/*****");
setEntity(新的UrlEncodedFormEntity(nameValuePairs));
HttpResponse response=httpclient.execute(httppost);
HttpEntity=response.getEntity();
is=entity.getContent();
}捕获(例外e){
e(“Log_标记”,“http连接错误”+e.toString());
}
//将响应转换为字符串
试一试{
BufferedReader reader=新的BufferedReader(新的InputStreamReader(is,“iso-8859-1”),8;
StringBuilder sb=新的StringBuilder();
字符串行=null;
而((line=reader.readLine())!=null){
sb.追加(第+行“\n”);
}
is.close();
结果=sb.toString();
}捕获(例外e){
Log.e(“Log_标记”,“错误转换结果”+e.toString());
}
字符串usernameFromDB=“”;
字符串firstnameFromDB=“”;
字符串lastnameFromDB=“”;
字符串emailFromDB=“”;
字符串phoneFromDB=“”;
字符串skypeFromDB=“”;
字符串cityFromDB=“”;
字符串描述fromdb=“”;
试一试{
JSONArray jArray=新JSONArray(结果);
对于上面的(int i=0;i添加了完整的活动代码)当您第二次单击按钮时它会做什么?有错误吗?修复了此问题并找到了另一个。上面已编辑。