我想在ViewPager中添加3个底部点，像这样。
我使用FragmentActivity和支持库ViewPager。
当前回答
如果有人想要构建一个带有缩略图作为指示器的viewPager，可以选择使用这个库: 用于viewPager的ThumbIndicator，也可以将图像链接作为资源。
其他回答
我想针对上述问题发布一个更简单的解决方案，指标数字可以动态更改，只需更改一个变量值dotCounts=x，我所做的是这样的。
在可绘制文件夹中为页面选定指标创建一个名为“item_selected”的xml文件。
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval" android:useLevel="true"
android:dither="true">
<size android:height="8dp" android:width="8dp"/>
<solid android:color="@color/image_item_selected_for_dots"/>
</shape>
为未选中的指示器再创建一个名为“item_unselected”的xml文件
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval" android:useLevel="true"
android:dither="true">
<size android:height="8dp" android:width="8dp"/>
<solid android:color="@color/image_item_unselected_for_dots"/>
</shape>
现在将这部分代码添加到您想要显示指示器的位置，例如在Layout XML文件中的viewPager下面。
<RelativeLayout
android:id="@+id/viewPagerIndicator"
android:layout_width="match_parent"
android:layout_below="@+id/banner_pager"
android:layout_height="wrap_content"
android:gravity="center">
<LinearLayout
android:id="@+id/viewPagerCountDots"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerHorizontal="true"
android:gravity="center"
android:orientation="horizontal" />
</RelativeLayout>
将此函数添加到布局膨胀的活动文件或与上述xml文件相关的活动文件之上
private int dotsCount = 5; //No of tabs or images
private ImageView[] dots;
LinearLayout linearLayout;
private void drawPageSelectionIndicators(int mPosition){
if(linearLayout!=null) {
linearLayout.removeAllViews();
}
linearLayout=(LinearLayout)findViewById(R.id.viewPagerCountDots);
dots = new ImageView[dotsCount];
for (int i = 0; i < dotsCount; i++) {
dots[i] = new ImageView(context);
if(i==mPosition)
dots[i].setImageDrawable(getResources().getDrawable(R.drawable.item_selected));
else
dots[i].setImageDrawable(getResources().getDrawable(R.drawable.item_unselected));
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT
);
params.setMargins(4, 0, 4, 0);
linearLayout.addView(dots[i], params);
}
}
最后，在你的onCreate方法中添加以下代码来引用你的布局和处理页面选择的位置
drawPageSelectionIndicators(0);
mPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
drawPageSelectionIndicators(position);
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
viewPager.addOnPageChangeListener(new OnPageChangeListener() {
@Override
public void onPageSelected(int position) {
switch (position) {
case 0:
img_page1.setImageResource(R.drawable.dot_selected);
img_page2.setImageResource(R.drawable.dot);
img_page3.setImageResource(R.drawable.dot);
img_page4.setImageResource(R.drawable.dot);
break;
case 1:
img_page1.setImageResource(R.drawable.dot);
img_page2.setImageResource(R.drawable.dot_selected);
img_page3.setImageResource(R.drawable.dot);
img_page4.setImageResource(R.drawable.dot);
break;
case 2:
img_page1.setImageResource(R.drawable.dot);
img_page2.setImageResource(R.drawable.dot);
img_page3.setImageResource(R.drawable.dot_selected);
img_page4.setImageResource(R.drawable.dot);
break;
case 3:
img_page1.setImageResource(R.drawable.dot);
img_page2.setImageResource(R.drawable.dot);
img_page3.setImageResource(R.drawable.dot);
img_page4.setImageResource(R.drawable.dot_selected);
break;
default:
break;
}
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
});
@Junaid提供的解决方案可以简化。 而不是创建一个选择器(tab_selector.xml)，你可以简单地直接在TabLayout上设置绘图。
<com.google.android.material.tabs.TabLayout
android:id="@+id/tabLayout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
app:tabBackground="@drawable/tab_indicator_default"
app:tabIndicator="@drawable/tab_indicator_selected"
app:tabIndicatorColor="<youColor>"
app:tabIndicatorGravity="center"
app:tabIndicatorHeight="8dp" />
app:tabIndicatorHeight与“tab_indicator_selected.xml”中的值保持一致。 按照这种方法，你可以保持TabLayout的默认动画。 通过编程，你必须将选项卡设置为所选:
object : ViewPager2.OnPageChangeCallback() {
override fun onPageSelected(position: Int) {
val tab = binding.tabLayout.getTabAt(position)
binding.tabLayout.selectTab(tab, true)
}
}
请注意，我使用了ViewPager2。应该有使用ViewPager的等效方法。
我的手工解决方案:
在布局中:
<LinearLayout
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/dots"
/>
在活动中
private final static int NUM_PAGES = 5;
private ViewPager mViewPager;
private List<ImageView> dots;
@Override
protected void onCreate(Bundle savedInstanceState) {
// ...
addDots();
}
public void addDots() {
dots = new ArrayList<>();
LinearLayout dotsLayout = (LinearLayout)findViewById(R.id.dots);
for(int i = 0; i < NUM_PAGES; i++) {
ImageView dot = new ImageView(this);
dot.setImageDrawable(getResources().getDrawable(R.drawable.pager_dot_not_selected));
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT
);
dotsLayout.addView(dot, params);
dots.add(dot);
}
mViewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
selectDot(position);
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
}
public void selectDot(int idx) {
Resources res = getResources();
for(int i = 0; i < NUM_PAGES; i++) {
int drawableId = (i==idx)?(R.drawable.pager_dot_selected):(R.drawable.pager_dot_not_selected);
Drawable drawable = res.getDrawable(drawableId);
dots.get(i).setImageDrawable(drawable);
}
}
以下是我提出的解决方案。
由于我们只需要在视图分页器中显示一些图像，因此避免了使用片段的麻烦。 实现了视图页面指示器(底部的点没有任何额外的库或插件) 在视图页面指示器(圆点)的触摸上，页面导航也在发生。 请不要忘记在资源中添加您自己的图片。 请随意评论和改进它。
A)下面是我的activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="schneider.carouseladventure.MainActivity">
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/viewpager"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<RelativeLayout
android:id="@+id/viewPagerIndicator"
android:layout_width="match_parent"
android:layout_height="55dp"
android:layout_alignParentBottom="true"
android:layout_marginTop="5dp"
android:gravity="center">
<LinearLayout
android:id="@+id/viewPagerCountDots"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerHorizontal="true"
android:gravity="center"
android:orientation="horizontal" />
</RelativeLayout>
</RelativeLayout>
B) pager_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/imageView" />
</LinearLayout>
C) MainActivity.java
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.LinearLayout;
public class MainActivity extends AppCompatActivity implements ViewPager.OnPageChangeListener, View.OnClickListener {
int[] mResources = {R.drawable.nature1, R.drawable.nature2, R.drawable.nature3, R.drawable.nature4,
R.drawable.nature5, R.drawable.nature6
};
ViewPager mViewPager;
private CustomPagerAdapter mAdapter;
private LinearLayout pager_indicator;
private int dotsCount;
private ImageView[] dots;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mViewPager = (ViewPager) findViewById(R.id.viewpager);
pager_indicator = (LinearLayout) findViewById(R.id.viewPagerCountDots);
mAdapter = new CustomPagerAdapter(this, mResources);
mViewPager.setAdapter(mAdapter);
mViewPager.setCurrentItem(0);
mViewPager.setOnPageChangeListener(this);
setPageViewIndicator();
}
private void setPageViewIndicator() {
Log.d("###setPageViewIndicator", " : called");
dotsCount = mAdapter.getCount();
dots = new ImageView[dotsCount];
for (int i = 0; i < dotsCount; i++) {
dots[i] = new ImageView(this);
dots[i].setImageDrawable(getResources().getDrawable(R.drawable.nonselecteditem_dot));
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT
);
params.setMargins(4, 0, 4, 0);
final int presentPosition = i;
dots[presentPosition].setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
mViewPager.setCurrentItem(presentPosition);
return true;
}
});
pager_indicator.addView(dots[i], params);
}
dots[0].setImageDrawable(getResources().getDrawable(R.drawable.selecteditem_dot));
}
@Override
public void onClick(View v) {
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
Log.d("###onPageSelected, pos ", String.valueOf(position));
for (int i = 0; i < dotsCount; i++) {
dots[i].setImageDrawable(getResources().getDrawable(R.drawable.nonselecteditem_dot));
}
dots[position].setImageDrawable(getResources().getDrawable(R.drawable.selecteditem_dot));
if (position + 1 == dotsCount) {
} else {
}
}
@Override
public void onPageScrollStateChanged(int state) {
}
}
D) CustomPagerAdapter.java
import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
public class CustomPagerAdapter extends PagerAdapter {
private Context mContext;
LayoutInflater mLayoutInflater;
private int[] mResources;
public CustomPagerAdapter(Context context, int[] resources) {
mContext = context;
mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
mResources = resources;
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
View itemView = mLayoutInflater.inflate(R.layout.pager_item,container,false);
ImageView imageView = (ImageView) itemView.findViewById(R.id.imageView);
imageView.setImageResource(mResources[position]);
/* LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(950, 950);
imageView.setLayoutParams(layoutParams);*/
container.addView(itemView);
return itemView;
}
@Override
public void destroyItem(ViewGroup collection, int position, Object view) {
collection.removeView((View) view);
}
@Override
public int getCount() {
return mResources.length;
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
}
E) selecteditem_dot.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval" android:useLevel="true"
android:dither="true">
<size android:height="12dip" android:width="12dip"/>
<solid android:color="#7e7e7e"/>
</shape>
F) nonselecteditem_dot.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval" android:useLevel="true"
android:dither="true">
<size android:height="12dip" android:width="12dip"/>
<solid android:color="#d3d3d3"/>
</shape>
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