[英]pass value from one activity to another activity
我已經開發了一個使用soap webservices的登錄表單示例。
在我的應用程序中,我有一個開始活動HomePage.HomePage,並且我有一個按鈕(myaccount)。 當我單擊myaccount
按鈕時, androidloginexampleactivity
成功重定向到androidloginexampleactivity
。
在這里輸入詳細信息username
和password
。 詳細信息是正確的,這意味着它已通過username
重定向到HomePage。 我登錄成功,但是之后強制關閉。
這些是我的編碼部分:
Homepage.java是
public class HomePage extends Activity {
private Button account;
private TextView tv;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home);
Button account = (Button) findViewById(R.id.account);
TextView tv = (TextView) findViewById(R.id.textView1);
tv.setText("Welcome ,"+getIntent().getExtras().getString("username"));
// Listening to register new account link
account.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(getApplicationContext() , AndroidLoginExampleActivity.class);
startActivity(i);
}
});
}
}
AndroidLoginExampleActivity.java
public class AndroidLoginExampleActivity extends Activity {
private final String NAMESPACE = "http://ws.userlogin.com";
private final String URL = "http://192.168.1.168:8085/Login/services/Login?wsdl";
private final String SOAP_ACTION = "http://ws.userlogin.com/authentication";
private final String METHOD_NAME = "authentication";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button login = (Button) findViewById(R.id.btn_login);
login.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
loginAction();
}
});
}
private void loginAction(){
SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);
EditText userName = (EditText) findViewById(R.id.tf_userName);
String user_Name = userName.getText().toString();
EditText userPassword = (EditText) findViewById(R.id.tf_password);
String user_Password = userPassword.getText().toString();
//Pass value for userName variable of the web service
PropertyInfo unameProp =new PropertyInfo();
unameProp.setName("userName");//Define the variable name in the web service method
unameProp.setValue(user_Name);//set value for userName variable
unameProp.setType(String.class);//Define the type of the variable
request.addProperty(unameProp);//Pass properties to the variable
//Pass value for Password variable of the web service
PropertyInfo passwordProp =new PropertyInfo();
passwordProp.setName("password");
passwordProp.setValue(user_Password);
passwordProp.setType(String.class);
request.addProperty(passwordProp);
SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
envelope.setOutputSoapObject(request);
HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);
try{
androidHttpTransport.call(SOAP_ACTION, envelope);
SoapPrimitive response = (SoapPrimitive)envelope.getResponse();
String status = response.toString();
TextView result = (TextView) findViewById(R.id.tv_status);
result.setText(response.toString());
if(status.equals("Success!"))
{
Intent intent = new Intent(AndroidLoginExampleActivity.this,HomePage.class);
intent.putExtra("username",userName.getText().toString());
startActivity(intent);
}
else
{
// Code for Login failure
}
}
catch(Exception e){
}
}
}
如何解決dis錯誤?
這是我的logcat窗口:
07-17 15:52:00.997: E/AndroidRuntime(1798): FATAL EXCEPTION: main
07-17 15:52:00.997: E/AndroidRuntime(1798): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.androidlogin.ws/com.androidlogin.ws.HomePage}: java.lang.NullPointerException
.
.
.
dalvik.system.NativeStart.main(Native Method)
07-17 15:52:00.997: E/AndroidRuntime(1798): Caused by: java.lang.NullPointerException
07-17 15:52:00.997: E/AndroidRuntime(1798): at com.androidlogin.ws.HomePage.onCreate(HomePage.java:30)
只需檢查您的多余資產不為空:
if(getIntent().getExtras() != null) {
tv.setText("Welcome ," + getIntent().getExtras().getString("username"));
}
如我在HomePage.Java中所述,只需添加if()條件
您必須通過調用startActivityForResult(Intent, int)
而不是startActivity()
來啟動AndroidLoginExampleActivity
。 這樣,您可以將數據發送到被調用活動,並從被調用活動接收數據。
供您參考- 活動。
您的問題: 將價值從一項活動傳遞給另一項活動 +?
我的答案:您可以使用SharedPreferences
將值從一個活動傳遞到另一個活動。
設置值:
String inputName = "Peter";
String inputPassword = "I love Stackoverflow";
SharedPreferences prefs = getSharedPreferences("myPrefs", 0);
SharedPreferences editor = prefs.edit();
editor.putString("accountName", inputName);
editor.putString("accountPassword", inputPassword);
editor.commit();
要在其他活動中獲取inputName和inputPassword,請執行以下操作:
String prefOutputAccountName = "no name";
String prefOutputAccountPassword = "no password";
SharedPreferences prefs = getSharedPreferences("myPrefs", 0);
prefOutputAccountName = prefs.getString("accountName", prefOutputAccountName);
prefOutputAccountPassword = prefs.getString("accountPassword", prefOutputAccountPassword);
希望我能正確回答你的問題。
您的問題:將價值從一項活動傳遞給另一項活動+?
我的答案:您可以使用SharedPreferences將值從一個活動傳遞到另一個活動。
設置值:
String inputName = "Peter";
String inputPassword = "I love Stackoverflow";
SharedPreferences prefs = getSharedPreferences("myPrefs", 0);
SharedPreferences editor = prefs.edit();
editor.putString("accountName", inputName);
editor.putString("accountPassword", inputPassword);
editor.commit();
要在其他活動中獲取inputName和inputPassword,請執行以下操作:
String prefOutputAccountName = "no name";
String prefOutputAccountPassword = "no password";
SharedPreferences prefs = getSharedPreferences("myPrefs", 0);
prefOutputAccountName = prefs.getString("accountName", prefOutputAccountName);
prefOutputAccountPassword = prefs.getString("accountPassword", prefOutputAccountPassword);
希望我能正確回答你的問題。
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