java.lang.RuntimeException：無法在未調用Looper.prepare（）的線程內創建處理程序爲什麼？

當我跑第一個活動..沒有錯誤但是當我嘗試運行第二個活動錯誤「java.lang.RuntimeException：不能創建處理程序內部線程沒有調用Looper.prepare（）」java.lang.RuntimeException：無法在未調用Looper.prepare（）的線程內創建處理程序爲什麼？

活動，沒有彎針問題

package com.example.androidnotizer; 

import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.ResultSet; 
import java.sql.Statement; 

import android.app.Activity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.os.Handler; 
import android.view.Menu; 
import android.view.MenuInflater; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.TextView; 
import android.widget.Toast; 


public class LoginActivity extends Activity { 

public static final String URL="jdbc:mysql://10.0.2.2/notizer"; 
public static final String USER="root"; 
public static final String PASSWORD="apple"; 
public static final String Driver_Class="com.mysql.jdbc.Driver"; 
public static final int RED=-65536; 

Handler handler = new Handler(); 
Thread background; 
String uid,pass; 
int count=0; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_login); 
    TextView tv = (TextView)findViewById(R.id.textView4); 
    tv.setText(""); 
    Button login = (Button) findViewById(R.id.button1); 
    login.setOnClickListener(new OnClickListener(){ 
     @Override 
     public void onClick(View arg0) { 
      EditText et1 = (EditText)findViewById(R.id.editText1); 
      EditText et2 = (EditText)findViewById(R.id.editText2); 
      uid=et1.getText().toString(); 
      pass=et2.getText().toString(); 
      TextView tv = (TextView)findViewById(R.id.textView4); 
      tv.setText(""); 
      count=0; 
      doLogin(); 
     } 
    }); 

} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    MenuInflater inflater = getMenuInflater(); 
    inflater.inflate(R.menu.login,menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    switch (item.getItemId()) { 
     case R.id.action_signup: 
      Intent i = new Intent(LoginActivity.this,SignUpActivity.class); 
      startActivity(i); 
    } 
    return true; 
} 

public void doLogin(){ 
    background = new Thread(new Runnable(){ 
     @Override 
     public void run(){ 
      try{ 
       Class.forName(Driver_Class); 
       Connection con = DriverManager.getConnection(URL, USER, PASSWORD); 
       Statement st = con.createStatement(); 
       ResultSet rs =st.executeQuery("select * from login where user_id='"+ uid +"' and password='"+ pass +"'"); 
       while(rs.next()){ 
        count++; 
       } 
      }catch(Exception e){ 
       e.printStackTrace(); 
      } 
      Runnable r=new Runnable() { 
        @Override 
        public void run() { 
         if(count==0){ 
          Toast.makeText(getApplicationContext(), "Unsuccessful Login", Toast.LENGTH_SHORT).show(); 
          TextView tv = (TextView)findViewById(R.id.textView4); 
          tv.setText("Wrong user_id or password"); 
          tv.setTextColor(RED); 
         } 
         else{ 
          Intent i = new Intent(LoginActivity.this,NoticeActivity.class); 
          startActivity(i); 
         } 
        } 
       }; 
       handler.post(r); 
      } 
     } 
    ); 
    background.start(); 
} 

}

活動與尺蠖問題

package com.example.androidnotizer; 

import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.Statement; 

import android.app.Activity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.os.Handler; 
import android.util.SparseBooleanArray; 
import android.view.Menu; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.ArrayAdapter; 
import android.widget.Button; 
import android.widget.ListView; 
import android.widget.Toast; 

public class StudentSignUpActivity extends Activity implements OnClickListener { 

public static final String URL="jdbc:mysql://10.0.2.2/notizer"; 
public static final String USER="root"; 
public static final String PASSWORD="apple"; 
public static final String Driver_Class="com.mysql.jdbc.Driver"; 

Handler handler = new Handler(); 
Thread background; 

Button button,combi; 
ListView listView; 
ArrayAdapter<String> adapter; 
String fname,lname,mname,gender,mobile,designation,passPapers,roll,department,year; 
int count=0; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_student_sign_up); 
    Intent intent =getIntent(); 
    fname = intent.getStringExtra("fname"); 
    mname = intent.getStringExtra("mname"); 
    lname = intent.getStringExtra("lname"); 
    gender = intent.getStringExtra("gender"); 
    mobile = intent.getStringExtra("mobile"); 
    designation = intent.getStringExtra("designation"); 
    roll = intent.getStringExtra("roll"); 
    department = intent.getStringExtra("department"); 
    year = intent.getStringExtra("year"); 
    findViewById(); 
    String[] sports = getResources().getStringArray(R.array.papers_array); 
    adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_multiple_choice, sports); 
    listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE); 
    listView.setAdapter(adapter); 
    button.setOnClickListener(this); 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.student_sign_up, menu); 
    return true; 
} 

private void findViewById() { 
    listView = (ListView) findViewById(R.id.dept_listView1); 
    button = (Button) findViewById(R.id.done); 
} 

@Override 
public void onClick(View arg0) { 
    SparseBooleanArray checked = listView.getCheckedItemPositions(); 
    passPapers=""; 
    for (int i = 0; i < checked.size(); i++) { 
     int position = checked.keyAt(i); 
     if (checked.valueAt(i)) 
      if((i+1) < checked.size()){ 
       passPapers=passPapers+String.valueOf(adapter.getItem(position))+","; 
      } 
      else{ 
       passPapers=passPapers+String.valueOf(adapter.getItem(position)); 
      } 

    } 
    doSignUp(); 
} 

public void doSignUp(){ 
    Toast.makeText(getApplicationContext(),"Inside doSignUp()",Toast.LENGTH_LONG).show(); 
    background = new Thread(new Runnable(){ 
     @Override 
     public void run(){ 
      try{ 
       Toast.makeText(getApplicationContext(),"Inside try",Toast.LENGTH_LONG).show(); 
       Class.forName(Driver_Class); 
       Connection con = DriverManager.getConnection(URL, USER, PASSWORD); 
       Statement st = con.createStatement(); 
       //st.executeUpdate("insert into student(roll_no,fname,mname,lname,gender,mobile_no,department,year,pass_papers,desigantion) values('"+ roll +"','"+ fname +"','"+ mname +"','"+ lname +"','"+ gender +"','"+ mobile +"','"+ department +"','"+ year +"','"+ passPapers +"','"+ designation +"')"); 
       st.executeUpdate("insert into login(user_id,password) values('"+ roll +"','"+ roll +"')"); 
       count=1; 
      }catch(Exception e){ 
       count=0; 
       e.printStackTrace(); 
       Toast.makeText(getApplicationContext(),e.toString(),Toast.LENGTH_LONG).show(); 
      } 
      Runnable r=new Runnable() { 
        @Override 
        public void run() { 
         if(count==1){ 
          Toast.makeText(getApplicationContext(), "Successful Sign Up\nYour user_id : " + roll + "\nand password : " + roll, Toast.LENGTH_LONG).show(); 
          Intent i = new Intent(StudentSignUpActivity.this,NoticeActivity.class); 
          startActivity(i); 
         } 
         else{ 
          Toast.makeText(getApplicationContext(), "Unsuccessful Sign Up\nTry Again", Toast.LENGTH_LONG).show(); 
          Intent i = new Intent(StudentSignUpActivity.this,SignUpActivity.class); 
          startActivity(i); 
         } 
        } 
       }; 
       handler.post(r); 
      } 
     } 
    ); 
    background.start(); 
} 

}

logcat的

12-10 06:49:48.823: E/AndroidRuntime(5021): FATAL EXCEPTION: Thread-344 
12-10 06:49:48.823: E/AndroidRuntime(5021): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare() 
12-10 06:49:48.823: E/AndroidRuntime(5021):  at android.os.Handler.<init>(Handler.java:197) 
12-10 06:49:48.823: E/AndroidRuntime(5021):  at android.os.Handler.<init>(Handler.java:111) 
12-10 06:49:48.823: E/AndroidRuntime(5021):  at android.widget.Toast$TN.<init>(Toast.java:324) 
12-10 06:49:48.823: E/AndroidRuntime(5021):  at android.widget.Toast.<init>(Toast.java:91) 
12-10 06:49:48.823: E/AndroidRuntime(5021):  at android.widget.Toast.makeText(Toast.java:238) 
12-10 06:49:48.823: E/AndroidRuntime(5021):  at com.example.androidnotizer.StudentSignUpActivity$1.run(StudentSignUpActivity.java:104) 
12-10 06:49:48.823: E/AndroidRuntime(5021):  at java.lang.Thread.run(Thread.java:841)

來源

2013-12-10 new_jerry

你解決了這個問題嗎？ –

是的，我有...只是增加了兩行 –

這將是很好，如果你在這裏分享你的努力 –

public void doSignUp(){ 
     background = new Thread(new Runnable() { 
      @Override 
      public void run() { 
       String error = "-1"; 
       try { 
        Class.forName(Driver_Class); 
        Connection con = DriverManager.getConnection(URL, USER, PASSWORD); 
        Statement st = con.createStatement(); 
        st.executeUpdate("insert into login(user_id,password) values('"+ roll +"','"+ roll +"')"); 
        count=1; 
       } catch(Exception e) { 
        count=0; 
        e.printStackTrace(); 
        error = e.toString(); 
       } 
       final String cause = error; 
       runOnUiThread(new Runnable() { 
        @Override 
        public void run() { 
         if(count==1) { 
          Toast.makeText(getApplicationContext(), "Successful Sign Up\nYour user_id : " + roll + "\nand password : " + roll, Toast.LENGTH_LONG).show(); 
          Intent i = new Intent(StudentSignUpActivity.this,NoticeActivity.class); 
          startActivity(i); 
         } else { 
          Toast.makeText(getApplicationContext(), "Unsuccessful Sign Up\nTry Again (Cause : " + cause + ")", Toast.LENGTH_LONG).show(); 
          Intent i = new Intent(StudentSignUpActivity.this,SignUpActivity.class); 
          startActivity(i); 
         } 
        } 
       }); 
      } 
     }); 
     background.start(); 
    }

試試這個樣本

來源

2013-12-10 12:12:28 Autocrab

你的意思是第二項活動？ –

是的。你在單獨的線程（doSignUp）中進行烤麪包，但是你不允許在單獨的線程中修改UI。 – Autocrab

這沒有幫助........猜我沒有選擇。必須使用looper類 –

你必須要逃避UI線程本身敬酒消息。使用此：

LoginActivity.this.runOnUiThread(new Runnable() { 
     public void run() { 

     if(count==1){ 
         Toast.makeText(getApplicationContext(), "Successful Sign Up\nYour user_id : " + roll + "\nand password : " + roll, Toast.LENGTH_LONG).show(); 
         Intent i = new Intent(StudentSignUpActivity.this,NoticeActivity.class); 
         startActivity(i); 
        } 
     else{ 
         Toast.makeText(getApplicationContext(), "Unsuccessful Sign Up\nTry Again", Toast.LENGTH_LONG).show(); 
         Intent i = new Intent(StudentSignUpActivity.this,SignUpActivity.class); 
         startActivity(i); 
        } 
         });

把這個內創建的線程。

來源

2013-12-10 12:25:48 SoulRayder

java.lang.RuntimeException：無法在未調用Looper.prepare（）的線程內創建處理程序爲什麼？

回答

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