Android 反压法误差
我正在使用身份验证进入页面,经过身份验证后,只有用户进入页面。我为onbackpressed()编写了一个代码,但它不起作用。这里DatabaseDemo和Login是两个类。当我按下后退按钮时,将显示带有用户名和密码的登录类 DatabaseDemo.javaAndroid 反压法误差,android,android-intent,Android,Android Intent,我正在使用身份验证进入页面,经过身份验证后,只有用户进入页面。我为onbackpressed()编写了一个代码,但它不起作用。这里DatabaseDemo和Login是两个类。当我按下后退按钮时,将显示带有用户名和密码的登录类 DatabaseDemo.java public class DatabaseDemo extends TabActivity { DatabaseHelper dbHelper; GridView grid; TextView txtTest;
public class DatabaseDemo extends TabActivity {
DatabaseHelper dbHelper;
GridView grid;
TextView txtTest;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
SetupTabs();
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
menu.add(1, 1, 1, "Add Employee");
return true;
}
public boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
//Add employee
case 1:
Intent addIntent=new Intent(this,AddEmployee.class);
startActivity(addIntent);
break;
}
super.onOptionsItemSelected(item);
return false;
}
void SetupTabs()
{
TabHost host=getTabHost();
TabHost.TabSpec spec=host.newTabSpec("tag1");
Intent in1=new Intent(this, AddEmployee.class);
spec.setIndicator("Add Employee");
spec.setContent(in1);
TabHost.TabSpec spec2=host.newTabSpec("tag2");
Intent in2=new Intent(this, GridList.class);
spec2.setIndicator("Employees");
spec2.setContent(in2);
host.addTab(spec);
host.addTab(spec2);
}
@Override
public void onBackPressed()
{
Intent i = new Intent(DatabaseDemo.this, Login.class);
startActivity(i);
}
}
我正在上更多的课,其他方面都很好
Login.java
public class Login extends Activity implements OnClickListener{
Button btn;
EditText et1, et2;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
btn = (Button)findViewById(R.id.btnlogin);
btn.setOnClickListener(this);
et1 = (EditText)findViewById(R.id.Leditename);
et2 = (EditText)findViewById(R.id.Leditpw);
}
@Override
public void onBackPressed()
{
super.onBackPressed();
finish();
}
@Override
public void onClick(View v) {
String ename = et1.getText().toString().trim();
System.out.println("ename is..." +ename);
String epw = et2.getText().toString().trim();
System.out.println("Password is..." +epw);
if(ename.equals("srikanth") && epw.equals("12345")){
Toast.makeText(getApplicationContext(), "valid login..!", Toast.LENGTH_LONG).show();
Intent in = new Intent(getApplicationContext(), DatabaseDemo.class);
startActivity(in);
}
else
{
Toast.makeText(getApplicationContext(), "Invalid authentication..!", Toast.LENGTH_LONG).show();
Intent intent = new Intent(getApplicationContext(), Login.class);
startActivity(intent);
}
}
Logcat没有显示任何错误
02-14 17:45:33.595: I/ActivityManager(59): Starting activity: Intent { cmp=com.android.databaseex/.DatabaseDemo }
02-14 17:45:34.835: I/ActivityManager(59): Displayed activity com.android.databaseex/.DatabaseDemo: 1141 ms (total 1141 ms)
02-14 17:45:50.145: I/System.out(613): ename is...srikanth
02-14 17:45:50.145: I/System.out(613): Password is...12345
02-14 17:45:50.175: I/ActivityManager(59): Starting activity: Intent { cmp=com.android.databaseex/.DatabaseDemo }
02-14 17:45:51.055: I/ActivityManager(59): Displayed activity com.android.databaseex/.DatabaseDemo: 819 ms (total 819 ms)
您需要跳过
super.onBackPressed()代码>行:
@Override
public void onBackPressed()
{
Intent i = new Intent(DatabaseDemo.this, Login.class);
startActivity(i);
}
这是完美的工作,请先检查您的androidmanifest文件,是否有活动登录的条目?如果存在,则没有任何问题,否则请在清单文件中登录活动,而不是使用onkeydown()的onBackpressed方法
在活动中重写onBackPressed方法,如下所示
@Override
public void onBackPressed(){
Intent i = new Intent(DatabaseDemo.this, Login.class);
startActivity(i);
}
登录是启动时的第一个活动,是否需要在清单文件中添加其他时间?我在这里粘贴了我的日志。。我在日志中没有发现任何错误。。即使我删除了onBackPressed()方法,它也只能像这样工作。即使忽略onBackPressed仍然会导致相同的问题,那么我相信你的代码中一定有其他错误。请给我你的电子邮件id,以便我可以将我的代码发送到你的邮件中。是我代码的链接,我在那里放了6个类,我跳过了3个类,它们完成了设置值、获取值和DialogListener、实用程序类等常规操作。请看这个并问我是否需要更多..什么是TabHost=getTabHost()
在DatabaseDemo.java中?我猜应该是TabHost host=(TabHost)findViewById(R.id.your\u TabHost\u id\u in\u布局)代码>。解决这个问题,我希望它能起作用。我也试过这样做,但没有结果。一旦通过这个链接,你会发现我的程序更多的代码。pastebin.com/d5vvcM70
public boolean onKeyDown(int keyCode, KeyEvent event) {
// TODO Auto-generated method stub
if(keyCode == KeyEvent.KEYCODE_BACK){
Intent i = new Intent(DatabaseDemo.this, Login.class);
startActivity(i);
}
return super.onKeyDown(keyCode, event);
}
@Override
public void onBackPressed(){
Intent i = new Intent(DatabaseDemo.this, Login.class);
startActivity(i);
}