Question

在android中工作我已经按照在线教程创建了一个视图寻呼机，我想以编程方式添加文本。我已成功创建了大量添加4个视图，但是当我在视图之间滚动时，我总是得到相同的视图。我的代码如下。有没有办法让初始视图简单地说是Page1然后在滚动时它会说出Page2等等。

修改

为了澄清，我已经相当简化了我想要做的事情，最终目标是每个＆＃34;视图＆＃34;与众不同。例如，第1页包含textview，第2页包含图像视图，第3页包含一些较大的文本。

Page 1 = "This is page 1"
Page 2 = An image of a sheep
Page 3 = Big red text saying "BANG!"

XML

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/black">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >

        <android.support.v4.view.ViewPager
            android:id="@+id/viewpager"
            android:layout_width="fill_parent"
            android:layout_height="300dp" />

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:srcCompat="@drawable/myImage"
            android:id="@+id/imageView13" />

    </LinearLayout>
</RelativeLayout>

爪哇

import android.content.Context;
import android.graphics.Color;
import android.os.Bundle;
import android.os.Parcelable;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;


public class Testing extends AppCompatActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_testing);

        ViewPager vp = (ViewPager) findViewById(R.id.viewpager);
        vp.setAdapter(new MyPagerAdapter(this));
    }
}

class MyPagerAdapter extends PagerAdapter {

    private Context ctx;

    public MyPagerAdapter(Context context) {
        ctx = context;
    }

    // Set number of slides
    @Override
    public int getCount() {
        return 4;
    }

    @Override
    public Object instantiateItem(View collection, int position) {

        TextView tv =  new TextView(ctx);
        tv.setTextSize(50);
        tv.setTextColor(Color.WHITE);
        tv.setText("PAGE1");
        ((ViewPager) collection).addView(tv);
        return tv;
    }

    // Destroy
    @Override
    public void destroyItem(View collection, int position, Object view) {
        ((ViewPager) collection).removeView((View) view);
    }

    // View from object
    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == object;
    }

    // Parceable
    @Override
    public Parcelable saveState() {
        return null;
    }

    // Restore state
    @Override
    public void restoreState(Parcelable arg0, ClassLoader arg1) {
    }

    //Start Update
    @Override
    public void startUpdate(View arg0) {
    }

    // Finish update
    @Override
    public void finishUpdate(View arg0) {
    }
}

Answer 1

滚动页面时

位置更改...

@Override
public Object instantiateItem(View collection, int position) {

if(position==0){
    TextView tv =  new TextView(ctx);
    tv.setTextSize(50);
    tv.setTextColor(Color.WHITE);
    tv.setText("PAGE "+position);
    collection.addView(tv);
    return tv;
}else if(position==1){
   ImageView iv = new ImageView(ctx);
   iv.setImageResource(R.mipmap.ic_launcher);
   collection.addView(iv);
   return iv;
}else if(position==2){
   TextView tv =  new TextView(ctx);
    tv.setTextSize(50);
    tv.setTextColor(Color.WHITE);
    tv.setText("BANG");
    collection.addView(tv);
    return tv;
}else if(position==3){
   ImageView iv = new ImageView(ctx);
   iv.setImageResource(R.mipmap.ic_launcher);
   collection.addView(tv);
    return iv;
}

向viewPager，Android添加更多视图

1 个答案: