2018-08-24|2018-08-24 如何编写WeclomeSplash页面 2018-08-24如何编写WeclomeSplash页面

思路：利用sharedpreferences+ViewPager+handler+bitmap去编写引导页面。废话不说直接上代码

private Handler mHandler = new Handler(new Handler.Callback() { @Override public boolean handleMessage(Message message) { switch (message.what) { case 0x01: //利用bitmap加载图片 setBitmap(); break; default: break; } return false; } }); //利用bitmap加载图片 private void setBitmap() { ViewUtil.getViewWidth(mImageView, new OnViewListener() { @Override public void onView(int width, int height) { mBitmap = BitmapUtil.Resource(getResources(), R.drawable.host_splash, width, height); mImageView.setImageBitmap(mBitmap); } }); }

因为加载图片内存比较大，所以使用bitmap去加载，这里用一个bitmap方法类去加载.

public class BitmapUtil { /** * @param resources 加载文件的路径 * @param piexlW真正显示图片的宽 * @param pieylH真正显示图片的高 * @return 返回bitmap */ public static Bitmap Resource(Resources resources, int id, int piexlW, int pieylH) { BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true; //只加载图片宽高 options.inPreferredConfig = Bitmap.Config.ARGB_8888; //设置位深度,减少内存消耗 //预加载 BitmapFactory.decodeResource(resources, id, options); int oringinalW = options.outWidth; int oringinalH = options.outHeight; //真正加载 options.inJustDecodeBounds = false; options.inSampleSize = getSimpleSize(oringinalW, oringinalH, piexlW, pieylH); return BitmapFactory.decodeResource(resources, id, options); }private static int getSimpleSize(int oringinalW, int oringinalH, int piexlW, int pieylH) { int SimpleSize = 1; //设置采样率为1，不压缩if (oringinalW > oringinalH && oringinalW > piexlW) { SimpleSize = oringinalW / piexlW; } else if (oringinalW < oringinalH && oringinalH > pieylH) { SimpleSize = oringinalH / pieylH; } if (SimpleSize <= 0) { SimpleSize = 1; } return SimpleSize; } }

这样就可将主页面解析并加载到我们手机上面了

SharedPreferences preferences = getSharedPreferences("data", MODE_PRIVATE); isFirstload = preferences.getBoolean("isFirstload", true); mEditor = preferences.edit(); isFirstload(); }

利用sharedPreferences去缓存我们的登录信息，如果是第一次安装登录就加载跳转到我们的主页面，如果不是，就跳转到我们主页面Activity，这个没设么好说的

private void isFirstload() {if (isFirstload) { mHandler.postDelayed(new Runnable() { @Override public void run() { startActivity(new Intent(WelcomeActivity.this, WelcomeSplashActivity.class).setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK)); overridePendingTransition(R.anim.activity_right_in, R.anim.activity_left_out); } }, 1500); mEditor.putBoolean("isFirstload", false); mEditor.apply(); } else { mHandler.postDelayed(new Runnable() { @Override public void run() { startActivity(new Intent(WelcomeActivity.this, HomeActivity.class).setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK)); overridePendingTransition(R.anim.activity_right_in, R.anim.activity_left_out); } }, 1500); }}

这里有一个跳转的动画overridePendingTransition，这是要紧跟着start,finsh等Intent活动去使用的，具体为什么，我也不太清楚。
这样就跳转到了我们的引导页面。
引导页面是我们要准备几个XML文件，很简单的，想放什么图片就放什么图片.

这是WelcomeSplashActivity的XML文件，很简单，一个ViewPager放循环图片，一个LineaerLayout用来放指示器，剩下一个按钮是等到最后一张图片显示出来用来跳转到主页面的。接下来到OnCreate方法中去编写吧

@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); //隐藏状态栏 getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); setContentView(R.layout.activity_welcome_splash); //编写布局 initView(); //编写指示器 initPoint(); } private void initView() { //实例化控件 mViewPager = findViewById(R.id.viewpager_splash); mBtn_splash = findViewById(R.id.btn_splash); mlayout = findViewById(R.id.linear_layout_indicator); //添加视图 Id = new int[]{R.layout.splash_layout_1, R.layout.splash_layout_2, R.layout.splash_layout_3, R.layout.splash_layout_4}; for (int i = 0; i < Id.length; i++) { View view = LayoutInflater.from(this).inflate(Id[i], null); mViewList.add(view); } mViewPager.setPageTransformer(true, new DepthPageTransformer()); adapter = new ViewPagerAdapter(mViewList); mViewPager.setAdapter(adapter); mViewPager.setOnPageChangeListener(this); mBtn_splash.setOnClickListener(this); }private void initPoint() { mIvPointArray = new ImageView[mViewList.size()]; for (int i = 0; i < mViewList.size(); i++) { mIvpoint = new ImageView(this); LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(30, 30); mIvpoint.setLayoutParams(params); params.setMargins(10, 0, 10, 0); mIvPointArray[i] = mIvpoint; if (i == 0) { mIvpoint.setImageResource(R.drawable.shape_circle_yellow); } else { mIvpoint.setImageResource(R.drawable.shape_circle_white); }mlayout.addView(mIvpoint); } }@Override public void onPageScrolled(int i, float v, int i1) {}@Override public void onPageSelected(int i) { for (int j = 0; j < mIvPointArray.length; j++) { mIvPointArray[i].setImageResource(R.drawable.shape_circle_yellow); if (i != j) { mIvPointArray[j].setImageResource(R.drawable.shape_circle_white); } }if (i == mViewList.size() - 1) { mBtn_splash.setVisibility(View.VISIBLE); } else { mBtn_splash.setVisibility(View.INVISIBLE); } }@Override public void onPageScrollStateChanged(int i) {}@Override public void onClick(View view) { startActivity(new Intent(WelcomeSplashActivity.this, HomeActivity.class) .setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK)); }

initView()方法主要是实例化控件，然后去获取到我们之前准备的XML文件
并将图片设置到Adapter中.
mViewPager.setPageTransformer(true, new DepthPageTransformer());
这个是为了让动画有淡出淡入的效果，需要另一个工具类.不用设置.
initPoint()主要是设置指示器，然后监听WiewPager变化，实现指示器和图片联动.
哦，还有Adapter没有贴出，送上代码

class ViewPagerAdapter extends PagerAdapter { private List lists; public ViewPagerAdapter(List list) { this.lists = list; }@Override public int getCount() { if (lists != null) { return lists.size(); } return 0; }@Override public boolean isViewFromObject(@NonNull View view, @NonNull Object o) { return view == o; }@NonNull @Override public Object instantiateItem(@NonNull ViewGroup container, int position) { container.addView(lists.get(position)); return lists.get(position); }@Override public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) { container.removeView(lists.get(position)); } }

【2018-08-24|2018-08-24 如何编写WeclomeSplash页面】比较简单，就不在赘述了，最后实现效果：