我正在尝试实现一个简单的用户登录注册页面，但现在我已经实现了用户登录，我的应用程序崩溃了消息：eightmiles is unfortunately stopped。 eightmiles是我的包名。
我在此处发布了我的backgroundtask.java，signin.java和我的logcat文件。请帮帮我，告诉我为什么会崩溃我的应用程序。
Backgroundtask.java ：
public class Backgroundtask extends AsyncTask<String,Void,String> {
AlertDialog alertDialog;
Context ctx;
Backgroundtask(Context ctx)
{
this.ctx =ctx;
}
@Override
protected void onPreExecute() {
alertDialog = new AlertDialog.Builder(ctx).create();
alertDialog.setTitle("Login Information....");
}
@Override
protected String doInBackground(String... params) {
String reg_url = "http://8miles.freeiz.com/Register.php";
String login_url = "http://8miles.freeiz.com/getuserinfo.php";
String method = params[0];
if (method.equals("Register")) {
String name = params[1];
String user_name = params[2];
String user_pass = params[3];
try {
URL url = new URL(reg_url);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
//httpURLConnection.setDoInput(true);
OutputStream OS = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(OS, "UTF-8"));
String data = URLEncoder.encode("user", "UTF-8") + "=" + URLEncoder.encode(name, "UTF-8") + "&" +
URLEncoder.encode("user_name", "UTF-8") + "=" + URLEncoder.encode(user_name, "UTF-8") + "&" +
URLEncoder.encode("user_pass", "UTF-8") + "=" + URLEncoder.encode(user_pass, "UTF-8");
bufferedWriter.write(data);
bufferedWriter.flush();
bufferedWriter.close();
OS.close();
InputStream IS = httpURLConnection.getInputStream();
IS.close();
//httpURLConnection.connect();
httpURLConnection.disconnect();
return "Registration Success...";
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
else if(method.equals("login"))
{
String login_name = params[1];
String login_pass = params[2];
try {
URL url = new URL(login_url);
HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream,"UTF-8"));
String data = URLEncoder.encode("login_name","UTF-8")+"="+URLEncoder.encode(login_name,"UTF-8")+"&"+
URLEncoder.encode("login_pass","UTF-8")+"="+URLEncoder.encode(login_pass,"UTF-8");
bufferedWriter.write(data);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream,"iso-8859-1"));
String response = "";
String line = "";
while ((line = bufferedReader.readLine())!=null)
{
response+= line;
}
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
return response;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
@Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
@Override
protected void onPostExecute(String result) {
if(result.equals("Registration Success..."))
{
Toast.makeText(ctx, result, Toast.LENGTH_LONG).show();
}
else
{
alertDialog.setMessage(result);
alertDialog.show();
}
}
}
Signin.java
public class Signin extends Activity {
TextView signuplink;
EditText signusername , signpassword;
Userlocalstore userlocalstore;
Button signin;
String login_name;
String login_pass;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
signusername = (EditText) findViewById(R.id.susername);
signpassword = (EditText) findViewById (R.id.spassword);
userlocalstore = new Userlocalstore(this);
setContentView(R.layout.signin);
signin = (Button) findViewById(R.id.signinbutt);
signin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
userlogin(v);
//user signedinuser = new user(null,null);
//userlocalstore.storeuserdata(signedinuser);
//userlocalstore.setuserloggedin(true);
}
});
signuplink = (TextView) findViewById(R.id.signuplink);
signuplink.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent signuppage = new Intent ("com.example.eightmiles.SIGNUP");
startActivity(signuppage);
}
});
}
public void userlogin(View view)
{
login_name = signusername.getText().toString();
login_pass = signpassword.getText().toString();
String method = "login";
Backgroundtask backgroundtask = new Backgroundtask(this);
backgroundtask.execute(method,login_name,login_pass);
}
}
logcat的
07-20 08:56:55.992: D/OpenGLRenderer(5848): Render dirty regions requested: true
07-20 08:56:55.997: D/(5848): HostConnection::get() New Host Connection established 0xac1ef9f0, tid 5848
07-20 08:56:56.011: D/Atlas(5848): Validating map...
07-20 08:56:56.047: D/libEGL(5848): loaded /system/lib/egl/libEGL_emulation.so
07-20 08:56:56.048: D/libEGL(5848): loaded /system/lib/egl/libGLESv1_CM_emulation.so
07-20 08:56:56.053: D/libEGL(5848): loaded /system/lib/egl/libGLESv2_emulation.so
07-20 08:56:56.074: D/(5848): HostConnection::get() New Host Connection established 0xac1f5260, tid 5864
07-20 08:56:56.095: I/OpenGLRenderer(5848): Initialized EGL, version 1.4
07-20 08:56:56.144: D/OpenGLRenderer(5848): Enabling debug mode 0
07-20 08:56:56.183: W/EGL_emulation(5848): eglSurfaceAttrib not implemented
07-20 08:56:56.183: W/OpenGLRenderer(5848): Failed to set EGL_SWAP_BEHAVIOR on surface 0xa4824480, error=EGL_SUCCESS
07-20 08:56:57.438: W/EGL_emulation(5848): eglSurfaceAttrib not implemented
07-20 08:56:57.438: W/OpenGLRenderer(5848): Failed to set EGL_SWAP_BEHAVIOR on surface 0xa48244a0, error=EGL_SUCCESS
07-20 08:57:02.073: I/Choreographer(5848): Skipped 273 frames! The application may be doing too much work on its main thread.
07-20 08:57:03.397: W/EGL_emulation(5848): eglSurfaceAttrib not implemented
07-20 08:57:03.397: W/OpenGLRenderer(5848): Failed to set EGL_SWAP_BEHAVIOR on surface 0xa4824480, error=EGL_SUCCESS
07-20 08:57:11.917: D/AndroidRuntime(5848): Shutting down VM
07-20 08:57:11.917: E/AndroidRuntime(5848): FATAL EXCEPTION: main
07-20 08:57:11.917: E/AndroidRuntime(5848): Process: com.example.eightmiles, PID: 5848
07-20 08:57:11.917: E/AndroidRuntime(5848): java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference
07-20 08:57:11.917: E/AndroidRuntime(5848): at com.example.eightmiles.Signin.userlogin(Signin.java:71)
07-20 08:57:11.917: E/AndroidRuntime(5848): at com.example.eightmiles.Signin$1.onClick(Signin.java:47)
07-20 08:57:11.917: E/AndroidRuntime(5848): at android.view.View.performClick(View.java:4756)
07-20 08:57:11.917: E/AndroidRuntime(5848): at android.view.View$PerformClick.run(View.java:19749)
07-20 08:57:11.917: E/AndroidRuntime(5848): at android.os.Handler.handleCallback(Handler.java:739)
07-20 08:57:11.917: E/AndroidRuntime(5848): at android.os.Handler.dispatchMessage(Handler.java:95)
07-20 08:57:11.917: E/AndroidRuntime(5848): at android.os.Looper.loop(Looper.java:135)
07-20 08:57:11.917: E/AndroidRuntime(5848): at android.app.ActivityThread.main(ActivityThread.java:5221)
07-20 08:57:11.917: E/AndroidRuntime(5848): at java.lang.reflect.Method.invoke(Native Method)
07-20 08:57:11.917: E/AndroidRuntime(5848): at java.lang.reflect.Method.invoke(Method.java:372)
07-20 08:57:11.917: E/AndroidRuntime(5848): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
07-20 08:57:11.917: E/AndroidRuntime(5848): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
07-20 08:57:15.845: I/Process(5848): Sending signal. PID: 5848 SIG: 9
07-20 08:57:16.549: D/OpenGLRenderer(5876): Render dirty regions requested: true
07-20 08:57:16.555: D/(5876): HostConnection::get() New Host Connection established 0xa481b030, tid 5876
07-20 08:57:16.570: D/Atlas(5876): Validating map...
07-20 08:57:16.622: D/libEGL(5876): loaded /system/lib/egl/libEGL_emulation.so
07-20 08:57:16.623: D/libEGL(5876): loaded /system/lib/egl/libGLESv1_CM_emulation.so
07-20 08:57:16.633: D/libEGL(5876): loaded /system/lib/egl/libGLESv2_emulation.so
07-20 08:57:16.656: D/(5876): HostConnection::get() New Host Connection established 0xa481b1f0, tid 5891
07-20 08:57:16.682: I/OpenGLRenderer(5876): Initialized EGL, version 1.4
07-20 08:57:16.736: D/OpenGLRenderer(5876): Enabling debug mode 0
07-20 08:57:16.770: W/EGL_emulation(5876): eglSurfaceAttrib not implemented
07-20 08:57:16.770: W/OpenGLRenderer(5876): Failed to set EGL_SWAP_BEHAVIOR on surface 0xa4824340, error=EGL_SUCCESS
答案 0 :(得分：1)
您应该更改订单
setContentView(R.layout.signin);
signusername = (EditText) findViewById(R.id.susername);
signpassword = (EditText) findViewById (R.id.spassword);
userlocalstore = new Userlocalstore(this);
首先setContentView(R.layout.signin);，然后初始化观看次数。