Andriodjie——欢迎页3秒跳转到主页+banner图片轮播

//Welocome
public class Welocome extends Activity {
   

    private final long SPLASH_LENGTH = 3000;
    Handler handler = new Handler();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.welocom);
        handler.postDelayed(new Runnable() {  //使用handler的postDelayed实现延时跳转

            public void run() {

                Intent intent = new Intent(Welocome.this, MainActivity.class);
                startActivity(intent);
                finish();
            }
        }, SPLASH_LENGTH);//3秒后跳转至应用主界面MainActivity
    }

}

//MainActivity

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.RadioGroup;

public class MainActivity extends AppCompatActivity {
    private FrameLayout frameLayout;
    private RadioGroup radioGroup;
    private Fragment[] mFragments;
    private int mIndex;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        View decorView = getWindow().getDecorView();
        int option = View.SYSTEM_UI_FLAG_FULLSCREEN;
        decorView.setSystemUiVisibility(option);
        ActionBar actionBar = getSupportActionBar();
        actionBar.hide();
        initFragment();
        setRadioGroupListener();
    }



    private void initFragment() {
        radioGroup = (RadioGroup) findViewById(R.id.radioGroup);
        frameLayout = (FrameLayout) findViewById(R.id.fl_content);
        HomeFragment homeFragment = new HomeFragment();
        MeFragment meFragment = new MeFragment();
        WtFragment wtFragment = new WtFragment();
        CarFragment carFragment = new CarFragment();
        XxFragment xxFragment = new XxFragment();
        //添加到数组
        mFragments = new Fragment[]{homeFragment, wtFragment, xxFragment,carFragment,meFragment};
        //开启事务
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        //添加首页
        ft.add(R.id.fl_content, homeFragment).commit();
        //默认设置为第0个
        setIndexSelected(0);
    }


    public void setIndexSelected(int index) {
        if (mIndex == index) {
            return;
        }
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction ft = fragmentManager.beginTransaction();
        ft.hide(mFragments[