- android - 多次调用 OnPrimaryClipChangedListener
- android - 无法更新 RecyclerView 中的 TextView 字段
- android.database.CursorIndexOutOfBoundsException : Index 0 requested, 光标大小为 0
- android - 使用 AppCompat 时,我们是否需要明确指定其 UI 组件(Spinner、EditText)颜色
我对 Android Studio 和 Java 完全陌生,但通过许多教程成功制作了自己的应用程序。问题是,每当我在主屏幕中单击我的应用程序(启动/启动)时,它会立即让我离开 apk(崩溃)。我不确定为什么。我相信它已连接到我的 Main_Activity 文件,但我不确定。我也遵循了 Google 的教程“AdMob for Android - Android Studio 入门”。我制作了一个新的空白 Android 应用程序并按照教程进行操作,效果很好。但是,在我当前的应用程序中,它似乎崩溃了。
如果有人知道如何修复它,请告诉我。我已经遇到这个问题两周了,但仍然无法解决。谢谢。这是我当前应用程序的文件:
Main_Activity.java:
package com.xxxxxxx.xxxxxxxxxxx;
import com.xxxxxxx.xxxxxxxx.R;
import android.annotation.TargetApi;
import android.graphics.RectF;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.util.SparseArrayCompat;
import android.support.v4.view.ViewPager;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.Toolbar;
import android.text.Spannable;
import android.text.SpannableString;
import android.util.TypedValue;
import android.view.View;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.widget.ImageView;
import android.widget.ScrollView;
import android.widget.TextView;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import com.astuetz.PagerSlidingTabStrip;
import com.flaviofaria.kenburnsview.KenBurnsView;
import com.nineoldandroids.view.ViewHelper;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;
import java.util.Random;
public class MainActivity extends ActionBarActivity implements ScrollTabHolder, ViewPager.OnPageChangeListener {
private static AccelerateDecelerateInterpolator sSmoothInterpolator = new AccelerateDecelerateInterpolator();
private KenBurnsView mHeaderPicture;
private View mHeader;
private PagerSlidingTabStrip mPagerSlidingTabStrip;
private ViewPager mViewPager;
private PagerAdapter mPagerAdapter;
private Toolbar toolbar;
private TextView title;
private ImageView icon;
private int mActionBarHeight;
private int mMinHeaderHeight;
private int mHeaderHeight;
private int mMinHeaderTranslation;
private ImageView mHeaderLogo;
private RectF mRect1 = new RectF();
private RectF mRect2 = new RectF();
private TypedValue mTypedValue = new TypedValue();
private SpannableString mSpannableString;
private AlphaForegroundColorSpan mAlphaForegroundColorSpan;
int[] photos={R.drawable.photo1, R.drawable.phpto2, R.drawable.photo3, R.drawable.photo4, R.drawable.photo5, R.drawable.photo6, R.drawable.photo7, R.drawable.photo8, R.drawable.photo9};
KenBurnsView imageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
AdView mAdView = (AdView) findViewById(R.id.adView);
AdRequest adRequest = new AdRequest.Builder().build();
mAdView.loadAd(adRequest);
mMinHeaderHeight = getResources().getDimensionPixelSize(R.dimen.min_header_height);
mHeaderHeight = getResources().getDimensionPixelSize(R.dimen.header_height);
mMinHeaderTranslation = -mMinHeaderHeight + getActionBarHeight();
setContentView(R.layout.activity_main);
imageView =(KenBurnsView) findViewById(R.id.header_picture);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
icon = (ImageView) findViewById(R.id.icon);
title = (TextView) findViewById(R.id.title);
mSpannableString = new SpannableString(getString(R.string.actionbar_title));
mHeaderLogo = (ImageView) findViewById(R.id.header_thumbnail);
mHeader = findViewById(R.id.header);
mPagerSlidingTabStrip = (PagerSlidingTabStrip) findViewById(R.id.tabs);
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setOffscreenPageLimit(4);
mPagerAdapter = new PagerAdapter(getSupportFragmentManager());
mPagerAdapter.setTabHolderScrollingContent(this);
mViewPager.setAdapter(mPagerAdapter);
mPagerSlidingTabStrip.setViewPager(mViewPager);
mPagerSlidingTabStrip.setOnPageChangeListener(this);
mAlphaForegroundColorSpan = new AlphaForegroundColorSpan(0xffffffff);
ViewHelper.setAlpha(getActionBarIconView(), 0f);
getSupportActionBar().setBackgroundDrawable(null);
final Handler handler = new Handler();
Runnable runnable = new Runnable() {
int i=0;
public void run() {
// change images randomly
Random ran=new Random();
int i=ran.nextInt(photos.length);
//set image resources
imageView.setImageResource(photos[i]);
i++;
if(i>photos.length-1)
{
i=0;
}
handler.postDelayed(this, 7000); //for interval...
}
};
handler.postDelayed(runnable, 7000); //for initial delay..
}
@Override
public void onPageScrollStateChanged(int arg0) {
// nothing
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
// nothing
}
@Override
public void onPageSelected(int position) {
SparseArrayCompat<ScrollTabHolder> scrollTabHolders = mPagerAdapter.getScrollTabHolders();
ScrollTabHolder currentHolder = scrollTabHolders.valueAt(position);
currentHolder.adjustScroll((int) (mHeader.getHeight() + ViewHelper.getTranslationY(mHeader)), mHeaderHeight);
}
@Override
public void onScroll(ScrollView view, int x, int y, int oldX, int oldY, int pagePosition)
{
if (mViewPager.getCurrentItem() == pagePosition)
{
mHeader.setTranslationY(Math.max(-view.getScrollY(), mMinHeaderTranslation));
float ratio = clamp(mHeader.getTranslationY() / mMinHeaderTranslation, 0.0f, 1.0f);
interpolate(mHeaderLogo, getActionBarIconView(), sSmoothInterpolator.getInterpolation(ratio));
setTitleAlpha(clamp(5.0F * ratio - 4.0F, 0.0F, 1.0F));
}
}
@Override
public void adjustScroll(int scrollHeight,int headerTranslationY) {
// nothing
}
public static float clamp(float value, float max, float min) {
return Math.max(Math.min(value, min), max);
}
private void interpolate(View view1, View view2, float interpolation) {
getOnScreenRect(mRect1, view1);
getOnScreenRect(mRect2, view2);
float scaleX = 1.0F + interpolation * (mRect2.width() / mRect1.width() - 1.0F);
float scaleY = 1.0F + interpolation * (mRect2.height() / mRect1.height() - 1.0F);
float translationX = 0.5F * (interpolation * (mRect2.left + mRect2.right - mRect1.left - mRect1.right));
float translationY = 0.5F * (interpolation * (mRect2.top + mRect2.bottom - mRect1.top - mRect1.bottom));
ViewHelper.setTranslationX(view1, translationX);
ViewHelper.setTranslationY(view1, translationY - ViewHelper.getTranslationY(mHeader));
ViewHelper.setScaleX(view1, scaleX);
ViewHelper.setScaleY(view1, scaleY);
}
private RectF getOnScreenRect(RectF rect, View view) {
rect.set(view.getLeft(), view.getTop(), view.getRight(), view.getBottom());
return rect;
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public int getActionBarHeight() {
if (mActionBarHeight != 0) {
return mActionBarHeight;
}
if(Build.VERSION.SDK_INT > Build.VERSION_CODES.HONEYCOMB){
getTheme().resolveAttribute(android.R.attr.actionBarSize, mTypedValue, true);
}else{
getTheme().resolveAttribute(R.attr.actionBarSize, mTypedValue, true);
}
mActionBarHeight = TypedValue.complexToDimensionPixelSize(mTypedValue.data, getResources().getDisplayMetrics());
return mActionBarHeight;
}
private void setTitleAlpha(float alpha) {
mAlphaForegroundColorSpan.setAlpha(alpha);
mSpannableString.setSpan(mAlphaForegroundColorSpan, 0, mSpannableString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
title.setText(mSpannableString);
}
private ImageView getActionBarIconView() {
return icon;
}
public class PagerAdapter extends FragmentPagerAdapter {
private SparseArrayCompat<ScrollTabHolder> mScrollTabHolders;
private final String[] TITLES = { "Home", "Install", "About", "Media", "Survey", "Upcoming", "News", "Help", "Credits", "Share", "More"};
private ScrollTabHolder mListener;
public PagerAdapter(FragmentManager fm) {
super(fm);
mScrollTabHolders = new SparseArrayCompat<ScrollTabHolder>();
}
public void setTabHolderScrollingContent(ScrollTabHolder listener) {
mListener = listener;
}
@Override
public CharSequence getPageTitle(int position) {
return TITLES[position];
}
@Override
public int getCount() {
return TITLES.length;
}
@Override
public Fragment getItem(int position) {
ScrollTabHolderFragment fragment = (ScrollTabHolderFragment) ScrollViewFragment.newInstance(position);
mScrollTabHolders.put(position, fragment);
if (mListener != null) {
fragment.setScrollTabHolder(mListener);
}
return fragment;
}
public SparseArrayCompat<ScrollTabHolder> getScrollTabHolders() {
return mScrollTabHolders;
}
}
public class LinkButtons extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void goToSo (View view) {
goToUrl ( "http://stackoverflow.com/");
}
public void goToSu (View view) {
goToUrl ( "http://superuser.com/");
}
private void goToUrl (String url) {
Uri uriUrl = Uri.parse(url);
Intent launchBrowser = new Intent(Intent.ACTION_VIEW, uriUrl);
startActivity(launchBrowser);
}
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:ads="http://schemas.android.com/apk/res-auto"
android:layout_height="match_parent" >
<android.support.v4.view.ViewPager
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<FrameLayout
android:id="@+id/header"
android:layout_width="match_parent"
android:layout_height="298dp" >
<com.google.android.gms.ads.AdView
android:id="@+id/adView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_alignParentBottom="true"
ads:adSize="BANNER"
ads:adUnitId="@string/banner_ad_unit_id">
</com.google.android.gms.ads.AdView>
<com.flaviofaria.kenburnsview.KenBurnsView
android:id="@+id/header_picture"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="@drawable/photo1"
/>
<ImageView
android:id="@+id/header_thumbnail"
android:layout_width="@dimen/header_logo_size"
android:layout_height="@dimen/header_logo_size"
android:layout_gravity="center"
android:src="@drawable/header_thumbnail" />
<com.astuetz.PagerSlidingTabStrip
android:id="@+id/tabs"
android:layout_width="match_parent"
android:layout_height="48dip"
android:layout_gravity="bottom"
android:textColor="#ffffff"
app:pstsIndicatorColor="#ffffff"
app:pstsDividerColor="@android:color/transparent"
android:background="@android:color/transparent" />
</FrameLayout>
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="56dp" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<ImageView
android:id="@+id/icon"
android:layout_marginLeft="12dp"
android:layout_marginTop="6dp"
android:layout_marginBottom="6dp"
android:layout_width="44dp"
android:layout_height="44dp" />
<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center_vertical"
style="@style/TextAppearance.AppCompat.Widget.ActionBar.Title" />
</LinearLayout>
</android.support.v7.widget.Toolbar>
字符串.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">A Random App</string>
<string name="hello_world">This is a Test.</string>
<string name="action_settings">Settings[BETA]</string>
<string name="actionbar_title">A Random App.</string>
<string name="banner_ad_unit_id">ca-app-pub-xxxxxxxxxxxxxxx/xxxxxxxxxxxxx</string>
<string name="subscribe"><a href="https://www.google.com">Google</a></string>
<string name="apps"><a href="https://www.google.pl/">Google</a></string>
<string name="extra"><a href="https://www.google.pl/">Google</a></string>
构建.gradle
apply plugin: 'com.android.application'
android {
compileSdkVersion 23
buildToolsVersion "23.0.1"
defaultConfig {
applicationId "com.xrevolt.mmxstructures"
minSdkVersion 14
targetSdkVersion 23
versionCode 2
versionName "1.2.0"
}
buildTypes {
release {
apply plugin: 'announce'
/*
runProguard false
*/
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:21.0.+'
compile 'com.android.support:cardview-v7:21+'
compile 'com.flaviofaria:kenburnsview:1.0.5'
compile 'com.jpardogo.materialtabstrip:library:1.0.6'
compile 'com.nineoldandroids:library:2.4.0'
compile 'com.google.android.gms:play-services-ads:8.4.0'
}
最佳答案
嗯,我修好了。但现在 AdMob 横幅会在滚动图像后面的顶部弹出。我希望它位于底部并与scrollView 类一起留在那里。
修复:
package com.xxxxxxx.xxxxxxxxxxx;
import com.xxxxxxx.xxxxxxxx.R;
import android.annotation.TargetApi;
import android.graphics.RectF;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.util.SparseArrayCompat;
import android.support.v4.view.ViewPager;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.Toolbar;
import android.text.Spannable;
import android.text.SpannableString;
import android.util.TypedValue;
import android.view.View;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.widget.ImageView;
import android.widget.ScrollView;
import android.widget.TextView;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import com.astuetz.PagerSlidingTabStrip;
import com.flaviofaria.kenburnsview.KenBurnsView;
import com.nineoldandroids.view.ViewHelper;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;
import java.util.Random;
public class MainActivity extends ActionBarActivity implements ScrollTabHolder, ViewPager.OnPageChangeListener {
private static AccelerateDecelerateInterpolator sSmoothInterpolator = new AccelerateDecelerateInterpolator();
private KenBurnsView mHeaderPicture;
private View mHeader;
private PagerSlidingTabStrip mPagerSlidingTabStrip;
private ViewPager mViewPager;
private PagerAdapter mPagerAdapter;
private Toolbar toolbar;
private TextView title;
private ImageView icon;
private int mActionBarHeight;
private int mMinHeaderHeight;
private int mHeaderHeight;
private int mMinHeaderTranslation;
private ImageView mHeaderLogo;
private RectF mRect1 = new RectF();
private RectF mRect2 = new RectF();
private TypedValue mTypedValue = new TypedValue();
private SpannableString mSpannableString;
private AlphaForegroundColorSpan mAlphaForegroundColorSpan;
int[] photos={R.drawable.photo1, R.drawable.phpto2, R.drawable.photo3, R.drawable.photo4, R.drawable.photo5, R.drawable.photo6, R.drawable.photo7, R.drawable.photo8, R.drawable.photo9};
KenBurnsView imageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mMinHeaderHeight = getResources().getDimensionPixelSize(R.dimen.min_header_height);
mHeaderHeight = getResources().getDimensionPixelSize(R.dimen.header_height);
mMinHeaderTranslation = -mMinHeaderHeight + getActionBarHeight();
setContentView(R.layout.activity_main);
imageView =(KenBurnsView) findViewById(R.id.header_picture);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
icon = (ImageView) findViewById(R.id.icon);
title = (TextView) findViewById(R.id.title);
mSpannableString = new SpannableString(getString(R.string.actionbar_title));
mHeaderLogo = (ImageView) findViewById(R.id.header_thumbnail);
mHeader = findViewById(R.id.header);
mPagerSlidingTabStrip = (PagerSlidingTabStrip) findViewById(R.id.tabs);
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setOffscreenPageLimit(4);
mPagerAdapter = new PagerAdapter(getSupportFragmentManager());
mPagerAdapter.setTabHolderScrollingContent(this);
mViewPager.setAdapter(mPagerAdapter);
mPagerSlidingTabStrip.setViewPager(mViewPager);
mPagerSlidingTabStrip.setOnPageChangeListener(this);
mAlphaForegroundColorSpan = new AlphaForegroundColorSpan(0xffffffff);
ViewHelper.setAlpha(getActionBarIconView(), 0f);
getSupportActionBar().setBackgroundDrawable(null);
final Handler handler = new Handler();
Runnable runnable = new Runnable() {
int i=0;
public void run() {
// change images randomly
Random ran=new Random();
int i=ran.nextInt(photos.length);
//set image resources
imageView.setImageResource(photos[i]);
i++;
if(i>photos.length-1)
{
i=0;
}
handler.postDelayed(this, 7000); //for interval...
}
};
handler.postDelayed(runnable, 7000); //for initial delay..
AdView mAdView = (AdView) findViewById(R.id.adView); AdRequest adRequest = new AdRequest.Builder().build(); mAdView.loadAd(adRequest);
}
@Override
public void onPageScrollStateChanged(int arg0) {
// nothing
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
// nothing
}
@Override
public void onPageSelected(int position) {
SparseArrayCompat<ScrollTabHolder> scrollTabHolders = mPagerAdapter.getScrollTabHolders();
ScrollTabHolder currentHolder = scrollTabHolders.valueAt(position);
currentHolder.adjustScroll((int) (mHeader.getHeight() + ViewHelper.getTranslationY(mHeader)), mHeaderHeight);
}
@Override
public void onScroll(ScrollView view, int x, int y, int oldX, int oldY, int pagePosition)
{
if (mViewPager.getCurrentItem() == pagePosition)
{
mHeader.setTranslationY(Math.max(-view.getScrollY(), mMinHeaderTranslation));
float ratio = clamp(mHeader.getTranslationY() / mMinHeaderTranslation, 0.0f, 1.0f);
interpolate(mHeaderLogo, getActionBarIconView(), sSmoothInterpolator.getInterpolation(ratio));
setTitleAlpha(clamp(5.0F * ratio - 4.0F, 0.0F, 1.0F));
}
}
@Override
public void adjustScroll(int scrollHeight,int headerTranslationY) {
// nothing
}
public static float clamp(float value, float max, float min) {
return Math.max(Math.min(value, min), max);
}
private void interpolate(View view1, View view2, float interpolation) {
getOnScreenRect(mRect1, view1);
getOnScreenRect(mRect2, view2);
float scaleX = 1.0F + interpolation * (mRect2.width() / mRect1.width() - 1.0F);
float scaleY = 1.0F + interpolation * (mRect2.height() / mRect1.height() - 1.0F);
float translationX = 0.5F * (interpolation * (mRect2.left + mRect2.right - mRect1.left - mRect1.right));
float translationY = 0.5F * (interpolation * (mRect2.top + mRect2.bottom - mRect1.top - mRect1.bottom));
ViewHelper.setTranslationX(view1, translationX);
ViewHelper.setTranslationY(view1, translationY - ViewHelper.getTranslationY(mHeader));
ViewHelper.setScaleX(view1, scaleX);
ViewHelper.setScaleY(view1, scaleY);
}
private RectF getOnScreenRect(RectF rect, View view) {
rect.set(view.getLeft(), view.getTop(), view.getRight(), view.getBottom());
return rect;
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public int getActionBarHeight() {
if (mActionBarHeight != 0) {
return mActionBarHeight;
}
if(Build.VERSION.SDK_INT > Build.VERSION_CODES.HONEYCOMB){
getTheme().resolveAttribute(android.R.attr.actionBarSize, mTypedValue, true);
}else{
getTheme().resolveAttribute(R.attr.actionBarSize, mTypedValue, true);
}
mActionBarHeight = TypedValue.complexToDimensionPixelSize(mTypedValue.data, getResources().getDisplayMetrics());
return mActionBarHeight;
}
private void setTitleAlpha(float alpha) {
mAlphaForegroundColorSpan.setAlpha(alpha);
mSpannableString.setSpan(mAlphaForegroundColorSpan, 0, mSpannableString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
title.setText(mSpannableString);
}
private ImageView getActionBarIconView() {
return icon;
}
public class PagerAdapter extends FragmentPagerAdapter {
private SparseArrayCompat<ScrollTabHolder> mScrollTabHolders;
private final String[] TITLES = { "Home", "Install", "About", "Media", "Survey", "Upcoming", "News", "Help", "Credits", "Share", "More"};
private ScrollTabHolder mListener;
public PagerAdapter(FragmentManager fm) {
super(fm);
mScrollTabHolders = new SparseArrayCompat<ScrollTabHolder>();
}
public void setTabHolderScrollingContent(ScrollTabHolder listener) {
mListener = listener;
}
@Override
public CharSequence getPageTitle(int position) {
return TITLES[position];
}
@Override
public int getCount() {
return TITLES.length;
}
@Override
public Fragment getItem(int position) {
ScrollTabHolderFragment fragment = (ScrollTabHolderFragment) ScrollViewFragment.newInstance(position);
mScrollTabHolders.put(position, fragment);
if (mListener != null) {
fragment.setScrollTabHolder(mListener);
}
return fragment;
}
public SparseArrayCompat<ScrollTabHolder> getScrollTabHolders() {
return mScrollTabHolders;
}
}
public class LinkButtons extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void goToSo (View view) {
goToUrl ( "http://stackoverflow.com/");
}
public void goToSu (View view) {
goToUrl ( "http://superuser.com/");
}
private void goToUrl (String url) {
Uri uriUrl = Uri.parse(url);
Intent launchBrowser = new Intent(Intent.ACTION_VIEW, uriUrl);
startActivity(launchBrowser);
}
}
}
有人有解决这个问题的代码吗?
关于java - 启动应用程序时 AdMob 崩溃,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/36806579/
我正在编写一个具有以下签名的 Java 方法。 void Logger(Method method, Object[] args); 如果一个方法(例如 ABC() )调用此方法 Logger,它应该
我是 Java 新手。 我的问题是我的 Java 程序找不到我试图用作的图像文件一个 JButton。 (目前这段代码什么也没做,因为我只是得到了想要的外观第一的)。这是我的主课 代码: packag
好的,今天我在接受采访,我已经编写 Java 代码多年了。采访中说“Java 垃圾收集是一个棘手的问题,我有几个 friend 一直在努力弄清楚。你在这方面做得怎么样?”。她是想骗我吗?还是我的一生都
我的 friend 给了我一个谜语让我解开。它是这样的: There are 100 people. Each one of them, in his turn, does the following
如果我将使用 Java 5 代码的应用程序编译成字节码,生成的 .class 文件是否能够在 Java 1.4 下运行? 如果后者可以工作并且我正在尝试在我的 Java 1.4 应用程序中使用 Jav
有关于why Java doesn't support unsigned types的问题以及一些关于处理无符号类型的问题。我做了一些搜索,似乎 Scala 也不支持无符号数据类型。限制是Java和S
我只是想知道在一个 java 版本中生成的字节码是否可以在其他 java 版本上运行 最佳答案 通常,字节码无需修改即可在 较新 版本的 Java 上运行。它不会在旧版本上运行,除非您使用特殊参数 (
我有一个关于在命令提示符下执行 java 程序的基本问题。 在某些机器上我们需要指定 -cp 。 (类路径)同时执行java程序 (test为java文件名与.class文件存在于同一目录下) jav
我已经阅读 StackOverflow 有一段时间了,现在我才鼓起勇气提出问题。我今年 20 岁,目前在我的家乡(罗马尼亚克卢日-纳波卡)就读 IT 大学。足以介绍:D。 基本上,我有一家提供簿记应用
我有 public JSONObject parseXML(String xml) { JSONObject jsonObject = XML.toJSONObject(xml); r
我已经在 Java 中实现了带有动态类型的简单解释语言。不幸的是我遇到了以下问题。测试时如下代码: def main() { def ks = Map[[1, 2]].keySet()
一直提示输入 1 到 10 的数字 - 结果应将 st、rd、th 和 nd 添加到数字中。编写一个程序,提示用户输入 1 到 10 之间的任意整数,然后以序数形式显示该整数并附加后缀。 public
我有这个 DownloadFile.java 并按预期下载该文件: import java.io.*; import java.net.URL; public class DownloadFile {
我想在 GUI 上添加延迟。我放置了 2 个 for 循环,然后重新绘制了一个标签,但这 2 个 for 循环一个接一个地执行,并且标签被重新绘制到最后一个。 我能做什么? for(int i=0;
我正在对对象 Student 的列表项进行一些测试,但是我更喜欢在 java 类对象中创建硬编码列表,然后从那里提取数据,而不是连接到数据库并在结果集中选择记录。然而,自从我这样做以来已经很长时间了,
我知道对象创建分为三个部分: 声明 实例化 初始化 classA{} classB extends classA{} classA obj = new classB(1,1); 实例化 它必须使用
我有兴趣使用 GPRS 构建车辆跟踪系统。但是,我有一些问题要问以前做过此操作的人: GPRS 是最好的技术吗?人们意识到任何问题吗? 我计划使用 Java/Java EE - 有更好的技术吗? 如果
我可以通过递归方法反转数组,例如:数组={1,2,3,4,5} 数组结果={5,4,3,2,1}但我的结果是相同的数组,我不知道为什么,请帮助我。 public class Recursion { p
有这样的标准方式吗? 包括 Java源代码-测试代码- Ant 或 Maven联合单元持续集成(可能是巡航控制)ClearCase 版本控制工具部署到应用服务器 最后我希望有一个自动构建和集成环境。
我什至不知道这是否可能,我非常怀疑它是否可能,但如果可以,您能告诉我怎么做吗?我只是想知道如何从打印机打印一些文本。 有什么想法吗? 最佳答案 这里有更简单的事情。 import javax.swin
我是一名优秀的程序员,十分优秀!