今天停下php,研究了下Volley框架的源码,实现了瀑布流的效果。
要实现最终的瀑布流效果,需要掌握几点知识:
(1)自定义布局,因为我们要监听滑到底部的事件就要实现自定义的ScrollView并通过回调函数实现监听
(2)对Vollet框架的掌握,我们需要新建一个requestQueue队列,通过研究源码发现在新建这个队列的时候传入相应的构造函数,然后会调整其中的start方法,有四个线程池收发请求,每个在一个while循环中实现队列的监听。
(3)动态布局,在自定义的scrollView里面放一个LinearLay然后在代码里面计算每列的宽度,添加ImageView到每列的布局里面。
自定义的MyScrollView
package com.fallview; import com.android.volley.RetryPolicy; import android.content.Context; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import android.view.View.OnTouchListener; import android.widget.ScrollView; public class MyScrollView extends ScrollView implements OnTouchListener { public MyScrollView(Context context, AttributeSet attrs) { super(context, attrs); // TODO Auto-generated constructor stub } ScrollTouch scrollTouch; public void setScrollTouch(ScrollTouch touch) { scrollTouch = touch; this.setOnTouchListener(this); } @Override public boolean onTouch(View view, MotionEvent arg1) { // TODO Auto-generated method stub switch (arg1.getAction()) { case MotionEvent.ACTION_DOWN: break; case MotionEvent.ACTION_UP: if (view.getMeasuredHeight() <= getHeight() + getScrollY()) { scrollTouch.onButtom(); } return true; default: break; } return false; } public interface ScrollTouch { public void onButtom(); } }
实现的java主类
package com.fallview; import com.android.volley.RequestQueue; import com.android.volley.Response.Listener; import com.android.volley.toolbox.ImageRequest; import com.android.volley.toolbox.Volley; import com.example.wangyitest.R; import com.fallview.MyScrollView.ScrollTouch; import android.app.Activity; import android.graphics.Bitmap; import android.graphics.Bitmap.Config; import android.os.Bundle; import android.view.ViewGroup.LayoutParams; import android.widget.ImageView; import android.widget.LinearLayout; public class FallImageAct extends Activity implements PicAdds { String[] myPics = pics; LinearLayout linearLayout; int culomWidth; int culNum; RequestQueue queue; int time = 1; class scrollListener implements ScrollTouch { @Override public void onButtom() { // TODO Auto-generated method stub intLayOne(); } } @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.falllay); linearLayout = (LinearLayout) findViewById(R.id.Linearlay); ((MyScrollView) findViewById(R.id.scroll)) .setScrollTouch(new scrollListener()); int screenWidth = getWindowManager().getDefaultDisplay().getWidth(); culomWidth = (screenWidth - 4) / 3; culNum = myPics.length / 3; queue = Volley.newRequestQueue(getApplicationContext()); iniadd3Lay(); intLayOne(); } LinearLayout.LayoutParams params; private void iniadd3Lay() { // TODO Auto-generated method stub layout1 = new LinearLayout(getApplicationContext()); params = new LinearLayout.LayoutParams(culomWidth, LinearLayout.LayoutParams.WRAP_CONTENT); layout1.setPadding(2, 2, 2, 2); layout1.setOrientation(LinearLayout.VERTICAL); layout1.setLayoutParams(new LinearLayout.LayoutParams(culomWidth, LinearLayout.LayoutParams.WRAP_CONTENT)); linearLayout.addView(layout1); layout2 = new LinearLayout(getApplicationContext()); LinearLayout.LayoutParams params = new LinearLayout.LayoutParams( culomWidth, LinearLayout.LayoutParams.WRAP_CONTENT); layout2.setPadding(2, 2, 2, 2); layout2.setOrientation(LinearLayout.VERTICAL); layout2.setLayoutParams(new LinearLayout.LayoutParams(culomWidth, LinearLayout.LayoutParams.WRAP_CONTENT)); linearLayout.addView(layout2); layout3 = new LinearLayout(getApplicationContext()); params = new LinearLayout.LayoutParams(culomWidth, LinearLayout.LayoutParams.WRAP_CONTENT); layout3.setPadding(2, 2, 2, 2); layout3.setOrientation(LinearLayout.VERTICAL); layout3.setLayoutParams(new LinearLayout.LayoutParams(culomWidth, LinearLayout.LayoutParams.WRAP_CONTENT)); linearLayout.addView(layout3); } LinearLayout layout1; LinearLayout layout2; LinearLayout layout3; private void intLayOne() { // TODO Auto-generated method stub time++; if (time > 5) return; for (int i = 0; i < culNum; i++) { ImageRequest imageRequest = new ImageRequest(pics[i], new Listener<Bitmap>() { @Override public void onResponse(Bitmap response) { // TODO Auto-generated method stub ImageView imageView = new ImageView( getApplicationContext()); imageView.setLayoutParams(new LayoutParams(params)); imageView.setImageBitmap(response); layout1.addView(imageView); } }, culomWidth, 0, Config.RGB_565, null); queue.add(imageRequest); } intLayTwo(); } private void intLayTwo() { // TODO Auto-generated method stub for (int i = culNum; i < 2 * culNum; i++) { ImageRequest imageRequest = new ImageRequest(pics[i], new Listener<Bitmap>() { @Override public void onResponse(Bitmap response) { // TODO Auto-generated method stub ImageView imageView = new ImageView( getApplicationContext()); imageView.setLayoutParams(new LayoutParams(params)); imageView.setImageBitmap(response); layout2.addView(imageView); } }, culomWidth, 0, Config.RGB_565, null); queue.add(imageRequest); } intLaythree(); } private void intLaythree() { // TODO Auto-generated method stub for (int i = 2 * culNum; i < pics.length; i++) { ImageRequest imageRequest = new ImageRequest(pics[i], new Listener<Bitmap>() { @Override public void onResponse(Bitmap response) { // TODO Auto-generated method stub ImageView imageView = new ImageView( getApplicationContext()); imageView.setLayoutParams(new LayoutParams(params)); imageView.setImageBitmap(response); layout3.addView(imageView); } }, culomWidth, 0, Config.RGB_565, null); queue.add(imageRequest); } } }
时间: 2024-10-16 05:32:58