用ViewFlipper實現如相冊功能一樣
第一步:使用ViewFlipper控件
<ViewFlipper
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/vf_main_image"
></ViewFlipper>
第二步:因爲ViewFlipper不是高級控件,需要直接加值,需要自己加值。下面會有一步步的註釋
public class MainActivity extends AppCompatActivity {
private ViewFlipper vf_main_image;
private int images[]={R.drawable.s1,R.drawable.s2,R.drawable.s3};
private GestureDetector gesture;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
vf_main_image = (ViewFlipper) findViewById(R.id.vf_main_image);
//一個一個加控件
for (int i = 0; i < images.length; i++) {
ImageView iv=new ImageView(this);
iv.setImageResource(images[i]);
vf_main_image.addView(iv);
}
//實例化GestureDetector手勢檢測器類
//第二個參數爲手勢監聽事件
//相冊是左右滑動,所以在OnFling事件下實現
gesture = new GestureDetector(this, new GestureDetector.OnGestureListener() {
@Override
public boolean onDown(MotionEvent e) {
Log.i("test","onDown——按下");
return false;
}
@Override
public void onShowPress(MotionEvent e) {
Log.i("test","onShowPress——長按一下會調用");
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
Log.i("test","onSingleTapUp——輕按");
return false;
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
Log.i("test","onScroll——滑動");
return false;
}
@Override
public void onLongPress(MotionEvent e) {
Log.i("test","onLongPress——長按");
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
Log.i("test","onFling——拖動結束");
//右滑代表上一張
// e1,代表向右滑動時,按下的點
// e2代表拖動擡起的點
if(e2.getX()-e1.getX()>100){
vf_main_image.showPrevious();
// vf_main_image.setInAnimation(MainActivity.this,R.anim.left_in);
// vf_main_image.setOutAnimation(MainActivity.this,R.anim.right_out);
}
//左滑代表下一張
// e1,代表向左滑動時,按下的點
// e2代表拖動擡起的點
if(e1.getX()-e2.getX()>100){
vf_main_image.showNext();
// vf_main_image.setInAnimation(MainActivity.this,R.anim.right_in);
// vf_main_image.setOutAnimation(MainActivity.this,R.anim.left_out);
}
return false;
}
});
}
//因爲有一個Activity的觸摸事件,和拖動事件,那麼到底調用哪一個呢
//解決方法:
//調用Activity的觸摸事件時調用手勢的觸摸事件
@Override
public boolean onTouchEvent(MotionEvent event) {
return gesture.onTouchEvent(event);
}
}