今天停止php，在研究Volley框架的源代码，实现了瀑布流的效果。
为了实现最终的级联效应，一些需要掌握的知识：
（1）自己定义布局，由于我们要监听滑究竟部的事件就要实现自己定义的ScrollView并通过回调函数实现监听
（2）对Vollet框架的掌握。我们须要新建一个requestQueue队列。通过研究源代码发如今新建这个队列的时候传入对应的构造函数。然后会调整当中的start方法。有四个线程池收发请求。每一个在一个while循环中实现队列的监听。
（3）动态布局。在自己定义的scrollView里面放一个LinearLay然后在代码里面计算每列的宽度，加入ImageView到每列的布局里面。
自己定义的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);
} }
}
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