Question

所以，我已经关注了这个特定的帖子（How to stop scrolling in a Gallery Widget?），但我无法让它正常工作。

我创建了一个扩展Gallery的自定义MyGallery类。我在上面的链接中添加了代码...我应该将<com.example.mygallery添加到XML文件中吗？如果是这样，我还要将导入添加到java文件中，还是因为XML文件而不需要？我很困惑。

我想简单地让画廊每次移动一张图像。

XML文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/carlot_background"
    >
<com.gallerytest.mygallery
    android:id="@+id/thisgallery"
    android:gravity="center"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />
</LinearLayout>

mygallery.java：

package com.gallerytest;

import android.content.Context;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.widget.Gallery;

public class mygallery extends Gallery {

    public mygallery(Context ctx, AttributeSet attrSet) {
        super(ctx);
        // TODO Auto-generated constructor stub
    }

    private boolean isScrollingLeft(MotionEvent e1, MotionEvent e2){ 
           return e2.getX() > e1.getX(); 
        }

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY){
      int kEvent;
      if(isScrollingLeft(e1, e2)){ //Check if scrolling left
        kEvent = KeyEvent.KEYCODE_DPAD_LEFT;
      }
      else{ //Otherwise scrolling right
        kEvent = KeyEvent.KEYCODE_DPAD_RIGHT;
      }
      onKeyDown(kEvent, null);
      return true;  
    }

}

main.java：包com.gallerytest;

import android.app.Activity;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;

public class main extends Activity {
    /** Called when the activity is first created. */

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

         mygallery gallery = (mygallery) findViewById(R.id.thisgallery);

         gallery.setAdapter(new AddImgAdp(this));

         gallery.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView parent, View v, int position, long id) {

                Toast.makeText(main.this, "Position=" + position, Toast.LENGTH_SHORT).show();
            }

        });

    }

    public class AddImgAdp extends BaseAdapter {
        int GalItemBg;
        private Context cont;


        private Integer[] Imgid = {
                R.drawable.image1, R.drawable.image2, R.drawable.image3, R.drawable.image4, R.drawable.image5};

        public AddImgAdp(Context c) {
            cont = c;
            TypedArray typArray = obtainStyledAttributes(R.styleable.Gallery1);
            GalItemBg = typArray.getResourceId(R.styleable.Gallery1_android_galleryItemBackground, 0);
            typArray.recycle();
        }

        public int getCount() {
            return Imgid.length;
        }

        public Object getItem(int position) {
            return position;
        }

        public long getItemId(int position) {
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView imgView = new ImageView(cont);

            imgView.setImageResource(Imgid[position]);

            imgView.setScaleType(ImageView.ScaleType.FIT_CENTER);
            imgView.setBackgroundResource(0x0106000d);
            imgView.setLayoutParams(new mygallery.LayoutParams(300, 240));

            return imgView;
        }
    }
}

我会喜欢一些帮助。谢谢！

〜瑞克

Answer 1

只需将attrSet参数添加到自定义库的构造函数中：

super(ctx, attrSet);

这对我有用。 Leo Vannucci

Answer 2

是。您应该在XML中使用 com.gallerytest.mygallery 而不是图库。一切都会很好，因为mygallery是Gallery的子类。不需要XML格式的导入。

Answer 3

更改XML是关键...我一直在获取TypeCastException，但在我的代码中找不到原因。最后在这篇文章中找到“你应该只使用com.gallerytest.mygallery代替XML中的Gallery”并解决了我的问题。非常感谢。

创建自定义图库 - 覆盖onFling

3 个答案: