Android 给scrollView添加毛玻璃效果的标题栏

效果如下

首先是布局文件，头部的标题栏是个压在scrollview上面的自定义控件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/window"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.npi.blureffect.ScrollViewActivity" >     <com.npi.blureffect.CustomScrollView         android:id="@+id/scrollView1"         android:layout_width="match_parent"         android:layout_height="match_parent"         android:layout_alignParentBottom="true"         android:layout_alignParentLeft="true"         android:layout_alignParentRight="true"         android:layout_alignParentTop="true" >         <LinearLayout             android:layout_width="match_parent"             android:layout_height="match_parent"             android:orientation="vertical" >             <Button                 android:id="@+id/button1"                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"                 android:layout_marginTop="50dp"                 android:text="Button" />             <TextView                 android:id="@+id/textView1"                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"                 android:layout_marginTop="50dp"                 android:text="Large Text"                 android:textAppearance="?android:attr/textAppearanceLarge" />             <RatingBar                 android:id="@+id/ratingBar1"                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"                 android:layout_marginTop="50dp" />             <RadioButton                 android:id="@+id/radioButton1"                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"                 android:layout_marginTop="50dp"                 android:text="RadioButton" />             <SeekBar                 android:id="@+id/seekBar1"                 android:layout_width="match_parent"                 android:layout_height="wrap_content"                 android:layout_marginTop="50dp" />             <ToggleButton                 android:id="@+id/toggleButton1"                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"                 android:layout_marginTop="50dp"                 android:text="ToggleButton" />             <SeekBar                 android:id="@+id/seekBar2"                 android:layout_width="match_parent"                 android:layout_height="wrap_content"                 android:layout_marginTop="50dp" />             <ProgressBar                 android:id="@+id/progressBar1"                 style="?android:attr/progressBarStyleLarge"                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"                 android:layout_marginTop="50dp" />             <TextView                 android:id="@+id/textView2"                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"                 android:layout_marginTop="50dp"                 android:text="Large Text"                 android:textAppearance="?android:attr/textAppearanceLarge" />             <CalendarView                 android:id="@+id/calendarView1"                 android:layout_width="match_parent"                 android:layout_height="match_parent"                 android:layout_marginTop="50dp" />         </LinearLayout>     </com.npi.blureffect.CustomScrollView>     <com.npi.blureffect.ScrollableImageView         android:id="@+id/blurred_image_header"         android:layout_width="match_parent"         android:layout_height="50dp"         android:background="#e8e8e8" /></RelativeLayout>

下面是自定义的scrollVIew，其实就是把里面探测scrollView滚动的方法给暴露到监听器上去

package com.npi.blureffect;import android.content.Context;import android.util.AttributeSet;import android.util.Log;import android.widget.ScrollView;public class CustomScrollView extends ScrollView {private ScrollViewListener scrollViewListener;public CustomScrollView(Context context) {super(context);// TODO Auto-generated constructor stub}public interface ScrollViewListener {        void onScrollChanged(CustomScrollView scrollView, int x, int y, int oldx, int oldy);    }   public CustomScrollView(Context context, AttributeSet attrs,              int defStyle) {          super(context, attrs, defStyle);      }        public CustomScrollView(Context context, AttributeSet attrs) {          super(context, attrs);      }       public void setScrollViewListener(ScrollViewListener scrollViewListener) {          this.scrollViewListener = scrollViewListener;      }        @Override      protected void onScrollChanged(int x, int y, int oldx, int oldy) {          super.onScrollChanged(x, y, oldx, oldy);          if (scrollViewListener != null) {              scrollViewListener.onScrollChanged(this, x, y, oldx, oldy);          }  //        Log.i("Alex", "$$$x是:"+x+" oldx是:"+oldx+"  Y是"+y+"oldY是"+oldy);    }          }

然后是最主要的activity

package com.npi.blureffect;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import com.npi.blureffect.CustomScrollView.ScrollViewListener;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.Canvas;import android.graphics.Matrix;import android.os.Bundle;import android.util.Log;import android.view.Menu;import android.view.MenuItem;import android.view.MotionEvent;import android.view.View;import android.view.View.OnTouchListener;import android.widget.ScrollView;public class ScrollViewActivity extends Activity {ScrollableImageView header;CustomScrollView scrollView ;Bitmap screen;<span style="white-space:pre"></span>@Override<span style="white-space:pre"></span>protected void onCreate(Bundle savedInstanceState) {<span style="white-space:pre"></span>super.onCreate(savedInstanceState);<span style="white-space:pre"></span>setContentView(R.layout.activity_scroll_view);<span style="white-space:pre"></span>header = (ScrollableImageView) findViewById(R.id.blurred_image_header);<span style="white-space:pre"></span>scrollView = (CustomScrollView) findViewById(R.id.scrollView1);<span style="white-space:pre"></span>initScrollView(header, scrollView);}<span style="white-space:pre"></span>public void  initScrollView(final ScrollableImageView header,final CustomScrollView scrollView){<span style="white-space:pre"></span>scrollView.setScrollViewListener(new ScrollViewListener() {<span style="white-space:pre"></span><span style="white-space:pre"></span>@Override<span style="white-space:pre"></span>public void onScrollChanged(CustomScrollView scrollView, int x, int y,<span style="white-space:pre"></span>int oldx, int oldy) {<span style="white-space:pre"></span>// TODO Auto-generated method stub<span style="white-space:pre"></span>Log.i("Alex", "x是:"+x+" oldx是:"+oldx+"  Y是"+y+"oldY是"+oldy);<span style="white-space:pre"></span>header.handleScroll(y, 0);<span style="white-space:pre"></span>}<span style="white-space:pre"></span>});<span style="white-space:pre"></span>scrollView.post(new Runnable() {<span style="white-space:pre"></span>@Override<span style="white-space:pre"></span>public void run() {<span style="white-space:pre"></span>// TODO Auto-generated method stub<span style="white-space:pre"></span>screen = getBitmapByView(scrollView);<span style="white-space:pre"></span>header.setoriginalImage(screen);<span style="white-space:pre"></span>}<span style="white-space:pre"></span>});}<span style="white-space:pre"></span>/**    * 截取scrollview的屏幕   * **/  public static Bitmap getBitmapByView(ScrollView scrollView) {      int h = 0;      Bitmap bitmap = null;       // 获取listView实际高度       for (int i = 0; i < scrollView.getChildCount(); i++) {           h += scrollView.getChildAt(i).getHeight();       }       Log.d("Alex", "实际高度:" + h);      Log.d("Alex", " 高度:" + scrollView.getHeight());      // 创建对应大小的bitmap      bitmap = Bitmap.createBitmap(scrollView.getWidth(), h,               Bitmap.Config.ARGB_8888);      final Canvas canvas = new Canvas(bitmap);      scrollView.draw(canvas);           return bitmap;   } }

这里用到的自定义图片控件和模糊工具类请到我之前的博客去查看