对齐子视图中ViewPager机器人中心 [英] Align the child views in center of the ViewPager android
问题描述
我需要设置子视图为ViewPager的中心，也是我想显示的下一个和previous欣赏到当前视图双方某些部分（如当前屏幕下方1）。但目前当前视图开始在ViewPager的左侧（像预期的屏幕下方2）。我怎样才能做到这一点？
I need to set the child view as center of the ViewPager and also I would like to show some part of the next and previous views to the current view sides(like current screen below 1). But currently the current view is starting at left side of the ViewPager(like expected screen below 2). How can I achieve that?
下面是我的code ..
Here is my code..
MyViewPagerAdapter
public class MyViewPagerAdapter extends PagerAdapter {
private Activity mActivity;
private int mPageCount;
public MyViewPagerAdapter(Activity activity,int pageCount) {
mActivity = activity;
mPageCount = pageCount;
}
@Override
public int getCount() {
return mPageCount;
}
@Override
public boolean isViewFromObject(View view, Object obj) {
return (view ==(View)obj);
}
@Override
public Object instantiateItem(ViewGroup container,final int position) {
ViewGroup viewGroup = (ViewGroup)mActivity.getLayoutInflater().inflate(
R.layout.item_view, null);
viewGroup.setBackgroundColor(randomColor());
TextView textView = (TextView)viewGroup.findViewById(R.id.textView1);
textView.setText("Page: "+(position+1));
Button button = (Button) viewGroup.findViewById(R.id.button1);
button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mActivity, "Hey, Its clicked!!! at page "+(position+1), Toast.LENGTH_LONG).show();
}
});
container.addView(viewGroup);
return viewGroup;
}
Random rnd = new Random();
private int randomColor(){
return Color.argb(255, rnd.nextInt(256), rnd.nextInt(256), rnd.nextInt(256));
}
@Override
public void destroyItem(ViewGroup collection, int position, Object view) {
//must be overridden else throws exception as not overridden.
Log.d("Tag", collection.getChildCount()+"");
collection.removeView((View) view);
}
@Override
public float getPageWidth(int position) {
return 0.8f;
}
}
MainActivity
public class MainActivity extends Activity {
private ViewPager viewPager;
LinearLayout linearLayout;
private int ID = 100;
private final int count = 8;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewPager = (ViewPager) findViewById(R.id.viewPager);
linearLayout = (LinearLayout) findViewById(R.id.indicator_layout);
generateIndicators(count);
MyViewPagerAdapter adapter = new MyViewPagerAdapter(this, count);
viewPager.setAdapter(adapter);
viewPager.setOnPageChangeListener(new OnPageChangeListener() {
int oldPosition = 0;
@Override
public void onPageSelected(int position) {
//this changes the old position's view state image
((TextView)linearLayout.getChildAt(oldPosition)).setText("");
oldPosition = position;
//this changes the current position's view state image
((TextView)linearLayout.getChildAt(position)).setText((position+1)+"");
}
//this method will be called repeatedly upto another item comes as front one(active one)
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
//this will be called as per scroll state
@Override
public void onPageScrollStateChanged(int arg0) {
}
});
viewPager.setOffscreenPageLimit(4);
}
private void generateIndicators(int count) {
/// Converts 14 dip into its equivalent px
int padd = (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 3, getResources().getDisplayMetrics());
for(int i=0;i<count;i++){
TextView textView = new TextView(this);
textView.setId(ID+i);
final int currentItem = i;
textView.setBackgroundResource(R.drawable.white_cell);
textView.setPadding(padd,padd,padd,padd);
/// Converts 14 dip into its equivalent px
int size = (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 10, getResources().getDisplayMetrics());
textView.setTextSize(size);
textView.setGravity(Gravity.CENTER);
/// Converts 14 dip into its equivalent px
int px = (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 30, getResources().getDisplayMetrics());
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(px, px);
linearLayout.addView(textView,params);
}
((TextView)linearLayout.getChildAt(0)).setText("1");
}
}
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<android.support.v4.view.ViewPager
android:id="@+id/viewPager"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" >
</android.support.v4.view.ViewPager>
<LinearLayout
android:id="@+id/indicator_layout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="19dp" >
</LinearLayout>
</RelativeLayout>
item_view.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="100dp"
android:layout_height="match_parent"
android:id="@+id/root_view"
android:orientation="vertical" >
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="Text"
android:textAppearance="?android:attr/textAppearanceLarge" />
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="click me" />
</LinearLayout>
当前屏幕
Current screen
预计屏幕
expected screen
推荐答案
最后，我已经加了我在GitHub上这个问题的解决方案。我做了一些pretty的技巧，以获得解决方法解决方案。你可以从下面的链接项目（其实我已经打算创建一个解释一个博客，但我力有那么多时间做）。
Finally, I have added my solution for this question in GitHub. I have done some pretty tricks to get the workaround solution. You can get the project from the below link(Actually I have planned to create a blog with the explanation , but I dint have that much time to do).
下面是链接（的 https://github.com/noundla/Sunny_Projects/tree/master/CenterLockViewPager ）
您必须从 com.noundla.centerviewpagersample.comps 包中的文件复制到您的项目。你可以看到，Viewpager的用法 MainActivity 类。
You have to copy the files from com.noundla.centerviewpagersample.comps package to your project. And you can see the usage of that Viewpager in MainActivity class.
请让我知道，如果任何人有问题与此有关。
Please let me know if anyone has problems with this.
这篇关于对齐子视图中ViewPager机器人中心的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
