Question

我有一个列表菜单，链接到另一个列表菜单和一个名为counter的活动。但是计数器不断抛出异常并且没有向我展示实际的反活动

这是下面的代码

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();

    }
   }

     }

工具类

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();

    }
   }

  }

计数器类

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;

公共类计数器扩展活动{

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，如果这有助于任何人

<?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>

我看不出任何想法会出现什么问题？

Answer 1

此行中的

Class ourclass = Class.forName("com.example.taekwondobuddy.util" + cheese);追加“。”在奶酪之前

尝试链接listActivity中的活动

1 个答案: