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我是Android Studio的新手。 我遵循Youtube和Google错误教程，但是这次我似乎找不到如何解决这个问题。Android Studio，应用程序停止工作
我创建了一个简单的登录和注册应用程序，它使用了一个mysql数据库。当我启动应用程序并点击注册按钮时，应用程序关闭并指出：“应用程序停止工作”。
我检查了logcat的，发现这个：
09-13 17:23:19.607 2229-2236/com.example.appname.appname E/art﹕ Failed sending reply to debugger: Broken pipe
09-13 17:23:47.756 2229-2229/com.example.appname.appname E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.appname.appname, PID: 2229
java.lang.IllegalStateException: Could not find method userReg(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.widget.Button
at android.view.View$DeclaredOnClickListener.resolveMethod(View.java:4479)
at android.view.View$DeclaredOnClickListener.onClick(View.java:4443)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Mainactivity.java
import android.app.Activity;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void userReg()
{
startActivity(new Intent(this, Register.class));
}
public void userLogin(View view)
{
}
}
Register.java
import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
public class Register extends Activity {
EditText ET_NAME,ET_USER_NAME,ET_USER_PASS;
String name,user_name,user_pass;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.register_layout);
ET_NAME = (EditText) findViewById(R.id.name);
ET_USER_NAME = (EditText) findViewById(R.id.new_user_name);
ET_USER_PASS = (EditText) findViewById(R.id.new_user_pass);
}
public void userReg(View view)
{
name = ET_NAME.getText().toString();
user_name = ET_USER_NAME.getText().toString();
user_pass = ET_USER_PASS.getText().toString();
String method = "register";
BackgroundTask backgroundTask = new BackgroundTask(this);
backgroundTask.execute(method,name,user_name,user_pass);
finish();
}
}
Backgroundtask.java
import android.content.Context;
import android.os.AsyncTask;
import android.widget.Toast;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
public class BackgroundTask extends AsyncTask<String, Void, String> {
Context ctx;
BackgroundTask(Context ctx)
{
this.ctx=ctx;
}
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected String doInBackground(String... params) {
String reg_url = "http://10.0.2.2.2/webapp/register.php";
String login_url = "http://10.0.2.2.2/webapp/login.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);
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();
return "Registration Success..";
} 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) {
Toast.makeText(ctx,result,Toast.LENGTH_LONG).show();
}
}
哪里是你的onclick代码？ –