我想计算两个双精度值之间的差
例如：lat1 = 12.2345673和lat2 = 12.2345672。在这里我想要结果为0.0000001。这恰好在Eclipse中计算double res = Double.compare（lat1，lat2）时没有得到。显示为0.0。请指定确切的公式来克服此问题
这段代码有什么错误？当我运行该程序时,它说"应用程序buttonProj(进程com.example.buttonproj)已意外停止.请再试一次"我刚尝试创建一个Add and Subtract按钮,用户可以点击它来增加或减少数字i .
package com.example.buttonproj;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity {
int counter;
Button add, sub;
TextView display;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
counter = 0;
add = (Button) findViewById(R.id.bAdd);
sub = (Button) findViewById(R.id.bSub);
display = (TextView) findViewById(R.id.textView1);
add.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
counter +=1;
display.setText(counter);
}
});
sub.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) { …E/PackageManager(78):包com.bountouris需要不可用的共享库com.google.android.maps; 失败!
这是我的日志文件.我的应用程序在它工作之前 我没有改变任何关于地图的事情.
编辑:
表现:
<uses-sdk android:minSdkVersion="15" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.INTERNET" />
<application android:icon="@drawable/ic_launcher" android:label="@string/app_name" >
<uses-library android:required="true" android:name="com.google.android.maps"/>
<activity android:name=".Syros1Activity" android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".MyMapActivity" android:label="@string/app_name"
android:theme="@android:style/Theme.NoTitleBar" >
</activity>
所以我有这个代码解决了java(android开发)中的二次方程式,它没有做任何事情!我按下按钮时根本没有给出答案...我甚至无法检查它是否正确.
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.support.v4.app.NavUtils;
public class QuadraticEquationSolver extends Activity {
public void main(String[] args){
Button calc = (Button) findViewById(R.id.Calculate);
calc.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
EditText X2 = (EditText)findViewById(R.id.X2);
EditText X = (EditText)findViewById(R.id.X);
EditText Num = (EditText)findViewById(R.id.Num);
TextView ans= (TextView) findViewById(R.id.finalans);
double x2 = Integer.parseInt(X2.getText().toString());
double x = Integer.parseInt(X.getText().toString());
double num = Integer.parseInt(Num.getText().toString());
double finalNum = ((x*-1) + (Math.sqrt((x*x)-(4*x*num))))/(2*x2);
ans.setText("answer: " + finalNum); …我想创建一个拍摄照片的应用程序,然后允许用户玩图片,就像给图片留一个小胡子,它没有什么严重的只是为了好玩.我想知道是否有人可以通过指向一些材料让我开始.
我试图通过意图从一个活动发送数据到另一个活动.但面临力量接近错误button click.
第一项活动:
btn1= (Button) findViewById(R.id.Next);
et = (EditText) findViewById(R.id.edit);
btn1.setOnClickListener(new Button.OnClickListener(){
public void onClick(View v)
{
Intent intent = new Intent();
intent.setClass(ViewchangerActivity.this, DisplayActivity.class);
intent.putExtra("Name", et.getText().toString());
startActivity(intent);
}
});
第二项活动:
public void onCreate(Bundle savedinstanceState)
{
super.onCreate(savedinstanceState);
setContentView(R.layout.main2);
TextView tv = (TextView) findViewById(R.id.Name);
Bundle b = getIntent().getExtras();
String str =b.getString("Name");
tv.setText(str);
}
logcat的:
android.content.ActivityNotFoundException: Unable to find explicit activity class
{org.android/org.android.DisplayActivity}; have you declared this activity in your AndroidManifest.xml?
当我将代码切换到另一个系统时,我收到错误(下面提到的代码),
配置:
操作系统:Windows 7 php服务器:Xampp
请帮我解决这个问题.提前致谢.
码:
<?php
class settings{
public $theme;
public $db_pf;
function __construct(){
$this->theme="default";
$this->db_pf="task_";
$this->paths();
$this->abbr();
$this->errors();
$this->enable_db_config();
}
function paths(){
define(ROOT,$_SERVER['DOCUMENT_ROOT']);
define(BP,"/task/");
define(ABSPATH,"/task/ta-admin/");
define(ADMPATH,"/task/administrator/");
define(INCLUDE_PATH,ABSPATH."includes/");
define(MODULE_PATH,ABSPATH."modules/");
define(CONTENT_PATH,ABSPATH."contents/");
define(THEME_PATH,ABSPATH."templates/".$this->theme."/");
define(STYLE_PATH,THEME_PATH."styles/");
define(IMAGE_PATH,THEME_PATH."images/");
define(JS_PATH,BP."assets/js/");
define(JQ_PATH,BP."assets/jq/");
}
function enable_db_config(){
include(ROOT.BP."ta-includes/class-db-config.php");
}
function abbr(){
define(task_title,"Admin-Quit Tasker-");
define(LOGIN_TITLE," Administrator Login...");
define(SLOGAN,"Enabling Solutions to your Tasks...");
}
function errors(){
define(NOTFOUND,"Page not found");
define(GOBACK," please press ok to go back...");
}
}
$obj_settings=new settings();
?>
错误:
Notice: Use of undefined constant ROOT - …