嘗試從列表活動鏈接活動

Question

我有一個列表菜單鏈接到另一個列表菜單和一個叫做計數器的活動。但是，計數器會拋出異常，而不是告訴我實際的計數器活動

下面的代碼下面

package com.example.taekwondobuddy.util; 

import android.app.ListActivity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 

public class Tools extends ListActivity{ 

String classes[] = {"Counter","Accelermeter","Timer"} ; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    // TODO Auto-generated method stub 
    super.onCreate(savedInstanceState); 
    setListAdapter(new ArrayAdapter<String>(Tools.this, android.R.layout.simple_list_item_1, classes)); 
} 


@Override 
protected void onListItemClick(ListView l, View v, int position, long id) { 
    // TODO Auto-generated method stub 
    super.onListItemClick(l, v, position, id); 
    String cheese = classes[position]; 
    try{ 
    Class ourclass = Class.forName("com.example.taekwondobuddy.util" + cheese); 
    Intent ourIntent = new Intent(Tools.this, ourclass); 
    startActivity(ourIntent); 
    } catch(ClassNotFoundException e){ 
     e.printStackTrace(); 

    } 
    } 

    } 

工具類

package com.example.taekwondobuddy.util; 

import android.app.ListActivity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 

public class Tools extends ListActivity{ 

String classes[] = {"Counter","Accelermeter","Timer"} ; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    // TODO Auto-generated method stub 
    super.onCreate(savedInstanceState); 
    setListAdapter(new ArrayAdapter<String>(Tools.this, android.R.layout.simple_list_item_1, classes)); 
} 


@Override 
protected void onListItemClick(ListView l, View v, int position, long id) { 
    // TODO Auto-generated method stub 
    super.onListItemClick(l, v, position, id); 
    String cheese = classes[position]; 
    try{ 
    Class ourclass = Class.forName("com.example.taekwondobuddy.util" + cheese); 
    Intent ourIntent = new Intent(Tools.this, ourclass); 
    startActivity(ourIntent); 
    } catch(ClassNotFoundException e){ 
     e.printStackTrace(); 

    } 
    } 

    } 

反類

package com.example.taekwondobuddy.util; 

import android.app.Activity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TextView; 

公共類計數器擴展活動{

int counter; 
Button add; 
Button sub; 
TextView display; 

public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.counter); 

    counter = 0; 
    add = (Button) findViewById(R.id.button1); 
    sub = (Button) findViewById(R.id.button2); 
    display = (TextView) findViewById(R.id.tvDisplay); 
    add.setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      counter++; 
      display.setText("Counter: " + counter); 
     } 
    }); 
    sub.setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      counter--; 
      display.setText("Counter: " + counter); 
     } 
    }); 
    } 

} 

和counter.xml如果這能幫助任何人

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="match_parent" > 


<TextView 
    android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:text="Counter: 0" 
android:textSize="45dp" 
android:layout_gravity="center" 
android:id="@+id/tvDisplay" 

    ></TextView> 

<Button 
    android:id="@+id/button1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentTop="true" 
    android:layout_centerHorizontal="true" 
    android:layout_marginTop="150dp" 
    android:text="Add" /> 

<Button 
    android:id="@+id/button2" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_below="@+id/button1" 
    android:layout_centerHorizontal="true" 
    android:layout_marginTop="25dp" 
    android:text="Subtract" /> 

</RelativeLayout> 

我看不出有什麼可以是錯的任何想法？

Answer 1

Class ourclass = Class.forName("com.example.taekwondobuddy.util" + cheese);在此行中附加「。」奶酪之前