ImageSwitcher效果不佳

Question

我有一个带有next和Back按钮的布局和一个ImageSwitcher

当我启动我的应用程序时，布局中没有图像（空白）

当我点击下一个按钮时，第一个图像出现

我想修复代码所以当我启动应用程序时，我看到mt第一个图像没有点击就出现了当我点击我移动到下一张照片

MainActivty Code

    Integer[] sabah = {R.drawable.sab_1,R.drawable.sab_2,R.drawable.sab_3,R.drawable.sab_4,R.drawable.sab_5};
int i = 0;
ImageView back_btu,next_btu;
ImageSwitcher imageSwitcher;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_sabah);

    imageSwitcher = (ImageSwitcher)findViewById(R.id.imgSw);
    imageSwitcher.setFactory(new ViewSwitcher.ViewFactory() {
        @Override
        public View makeView() {
            ImageView sabimageView = new ImageView(getApplicationContext());
            sabimageView.setScaleType(ImageView.ScaleType.FIT_START);
            sabimageView.setLayoutParams(new ImageSwitcher.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.MATCH_PARENT));
            return sabimageView;
        }
    });

    Animation in = AnimationUtils.loadAnimation(getApplicationContext(),R.anim.in);
    Animation out = AnimationUtils.loadAnimation(getApplicationContext(),R.anim.out);

    imageSwitcher.setAnimation(in);
    imageSwitcher.setAnimation(out);


    back_btu = (ImageView)findViewById(R.id.back_btu);
    next_btu =(ImageView)findViewById(R.id.next_btu);


}



public void backBtu(View view) {
    if(i >0){
        i--;
        imageSwitcher.setImageResource(sabah[i]);
    }
}

public void nextBtu(View view) {
    if(i<sabah.length-1){
        i++;
        imageSwitcher.setImageResource(sabah[i]);

    }
}

}