PageFlipper動態加載View

知識點:

     1.PageFlipper基本用法及動態添加View;

     2.PageFlipper結合手勢翻頁+特效;

     3.WindowManager的基本用法。

任意張圖片實現循環滑動,其實PageFlipper當前最多的子View個數(ChildViewCount)小於等於2.

 

 fliper_item.xml:

[java] 
<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="https://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:gravity="center" > 
 
    <ImageView 
        android:id="@+id/img" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:gravity="center" /> 
 
</LinearLayout> 

main.xml:

[java] 
<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="https://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical" > 
 
    <ViewFlipper 
        android:id="@+id/myViewFlipper" 
        android:layout_width="fill_parent" 
        android:layout_height="fill_parent" > 
         
    </ViewFlipper> 
 
</LinearLayout> 

MainActivity.java:

[java]
package com.xyz.pagefilter; 
 
import android.app.Activity; 
import android.content.Context; 
import android.graphics.PixelFormat; 
import android.os.Bundle; 
import android.os.Handler; 
import android.os.Message; 
import android.view.GestureDetector; 
import android.view.GestureDetector.OnGestureListener; 
import android.view.Gravity; 
import android.view.LayoutInflater; 
import android.view.MotionEvent; 
import android.view.View; 
import android.view.View.OnTouchListener; 
import android.view.Window; 
import android.view.WindowManager; 
import android.view.WindowManager.LayoutParams; 
import android.widget.ImageView; 
import android.widget.ViewFlipper; 
 
public class MainActivity extends Activity implements OnTouchListener, 
        OnGestureListener { 
 
    private LayoutInflater mInflater; 
    private WindowManager wm = null; 
    private WindowManager.LayoutParams wmParams = null; 
 
    private ImageView leftbtn = null; 
    private ImageView rightbtn = null; 
 
    private int mAlpha = 0; 
    private boolean isHide; 
 
    private int mCurrPos = 0; 
 
    private ViewFlipper viewFlipper = null; 
    private GestureDetector mGestureDetector; 
 
    private int[] mImages = new int[] { R.drawable.img_0, R.drawable.img_1, 
            R.drawable.img_2, R.drawable.img_3, R.drawable.img_4, 
            R.drawable.img_5, R.drawable.img_6, R.drawable.img_7, 
            R.drawable.img_8, R.drawable.img_9 }; 
 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        requestWindowFeature(Window.FEATURE_NO_TITLE); 
        setContentView(R.layout.main); 
 
        mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
        viewFlipper = (ViewFlipper) this.findViewById(R.id.myViewFlipper); 
        setView(mCurrPos, 0); 
        initFloatView(); 
 
        // viewFlipper.setLongClickable(true); 
        viewFlipper.setOnTouchListener(this); 
        mGestureDetector = new GestureDetector(this); 
 
    } 
 
    private void initFloatView() { 
        wm = (WindowManager) getApplicationContext().getSystemService( 
                Context.WINDOW_SERVICE); 
        wmParams = new WindowManager.LayoutParams(); 
 
        wmParams.type = LayoutParams.TYPE_PHONE;  
        wmParams.format = PixelFormat.RGBA_8888;  
         
        wmParams.flags = LayoutParams.FLAG_NOT_TOUCH_MODAL 
                | LayoutParams.FLAG_NOT_FOCUSABLE; 
 
        wmParams.x = 0; 
        wmParams.y = 0; 
 
        wmParams.width = 50; 
        wmParams.height = 50; 
 
        createLeftFloatView(); 
        createRightFloatView(); 
    } 
 
    private void createLeftFloatView() { 
        leftbtn = new ImageView(this); 
        leftbtn.setImageResource(R.drawable.prev); 
        leftbtn.setAlpha(0); 
        leftbtn.setOnClickListener(new View.OnClickListener() { 
            public void onClick(View arg0) { 
                movePrevious(); 
            } 
        }); 
         
        wmParams.gravity = Gravity.LEFT | Gravity.CENTER_VERTICAL; 
         
        wm.addView(leftbtn, wmParams); 
    } 
 
    private void createRightFloatView() { 
        rightbtn = new ImageView(this); 
        rightbtn.setImageResource(R.drawable.next); 
        rightbtn.setAlpha(0); 
        rightbtn.setOnClickListener(new View.OnClickListener() { 
            public void onClick(View arg0) { 
                moveNext(); 
            } 
        }); 
         
        wmParams.gravity = Gravity.RIGHT | Gravity.CENTER_VERTICAL; 
         
        wm.addView(rightbtn, wmParams); 
    } 
 
    private void setView(int curr, int next) { 
        View v = (View) mInflater.inflate(R.layout.flipper_item, null); 
        ImageView iv = (ImageView) v.findViewById(R.id.img); 
        // iv.setScaleType(ImageView.ScaleType.FIT_XY); 
        if (curr < next && next > mImages.length – 1) 
            next = 0; 
        else if (curr > next && next < 0) 
            next = mImages.length – 1; 
        iv.setImageResource(mImages[next]); 
        if (viewFlipper.getChildCount() > 1) { 
            viewFlipper.removeViewAt(0); 
        } 
        viewFlipper.addView(v, viewFlipper.getChildCount()); 
        mCurrPos = next; 
 
    } 
 
    private void movePrevious() { 
        setView(mCurrPos, mCurrPos – 1); 
        viewFlipper.setInAnimation(MainActivity.this, R.anim.in_leftright); 
        viewFlipper.setOutAnimation(MainActivity.this, R.anim.out_leftright); 
        viewFlipper.showPrevious(); 
    } 
 
    private void moveNext() { 
        setView(mCurrPos, mCurrPos + 1); 
        viewFlipper.setInAnimation(MainActivity.this, R.anim.in_rightleft); 
        viewFlipper.setOutAnimation(MainActivity.this, R.anim.out_rightleft); 
        viewFlipper.showNext(); 
    } 
 
    private Handler mHandler = new Handler() { 
        public void handleMessage(Message msg) { 
            if (msg.what == 1 && mAlpha < 255) { 
                mAlpha += 50; 
                if (mAlpha > 255) 
                    mAlpha = 255; 
                leftbtn.setAlpha(mAlpha); 
                leftbtn.invalidate(); 
                rightbtn.setAlpha(mAlpha); 
                rightbtn.invalidate(); 
                if (!isHide && mAlpha < 255) 
                    mHandler.sendEmptyMessageDelayed(1, 100); 
            } else if (msg.what == 0 && mAlpha > 0) { 
                mAlpha -= 10; 
                if (mAlpha < 0) 
                    mAlpha = 0; 
                leftbtn.setAlpha(mAlpha); 
                leftbtn.invalidate(); 
                rightbtn.setAlpha(mAlpha); 
                rightbtn.invalidate(); 
                if (isHide && mAlpha > 0) 
                    mHandler.sendEmptyMessageDelayed(0, 100); 
            } 
        } 
    }; 
 
    private void showFloatView() { 
        isHide = false; 
        mHandler.sendEmptyMessage(1); 
    } 
 
    private void hideFloatView() { 
        new Thread() { 
            public void run() { 
                try { 
                    Thread.sleep(1500); 
                    isHide = true; 
                    mHandler.sendEmptyMessage(0); 
                } catch (Exception e) { 
                } 
            } 
        }.start(); 
    } 
 
    @Override 
    public void onDestroy() { 
        super.onDestroy(); 
        wm.removeView(leftbtn); 
        wm.removeView(rightbtn); 
    } 
 
    @Override 
    public boolean onDown(MotionEvent e) { 
        return false; 
    } 
 
    @Override 
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, 
            float velocityY) { 
        int x = (int) (e2.getX() – e1.getX()); 
        if (x > 0) { 
            movePrevious(); 
        } else { 
            moveNext(); 
        } 
        return false; 
    } 
 
    @Override 
    public void onLongPress(MotionEvent e) { 
 
    } 
 
    @Override 
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, 
            float distanceY) { 
        return false; 
    } 
 
    @Override 
    public void onShowPress(MotionEvent e) { 
        // 用戶輕觸屏幕,尚末松開或拖動,註意,強調的是沒有沒有松開或者拖動狀態 
    } 
 
    @Override 
    public boolean onSingleTapUp(MotionEvent e) { 
        return false; 
    } 
 
    @Override 
    public boolean onTouch(View v, MotionEvent event) { 
        switch (event.getAction()) { 
        case MotionEvent.ACTION_MOVE: 
        case MotionEvent.ACTION_DOWN: 
            showFloatView(); 
            break; 
        case MotionEvent.ACTION_UP: 
            hideFloatView(); 
            break; 
        } 
        mGestureDetector.onTouchEvent(event); 
        return true; 
    } 

附加特效文件:
in_leftright.xml:

[cpp] 
<?xml version="1.0" encoding="utf-8"?> 
<set xmlns:android="https://schemas.android.com/apk/res/android" > 
 
    <translate 
        android:duration="500" 
        android:fromXDelta="-100%p" 
        android:toXDelta="0" /> 
 
    <alpha 
        android:duration="500" 
        android:fromAlpha="0.0" 
        android:toAlpha="1.0" /> 
 
</set> 
in_rightleft.xml:

[java]
<?xml version="1.0" encoding="utf-8"?> 
<set xmlns:android="https://schemas.android.com/apk/res/android" > 
    <translate 
        android:duration="500" 
        android:fromXDelta="100%p" 
        android:toXDelta="0" /> 
     
    <alpha 
        android:duration="500" 
        android:fromAlpha="0.0" 
        android:toAlpha="1.0" /> 
</set> 
out_leftright.xml:

[java] 
<?xml version="1.0" encoding="utf-8"?> 
<set xmlns:android="https://schemas.android.com/apk/res/android" > 
    <translate 
        android:duration="500" 
        android:fromXDelta="0" 
        android:toXDelta="100%p" /> 
     
    <alpha 
        android:duration="500" 
        android:fromAlpha="1.0" 
        android:toAlpha="0.0" /> 
</set> 
out_rightleft.xml:

[java]
<?xml version="1.0" encoding="utf-8"?> 
<set xmlns:android="https://schemas.android.com/apk/res/android" > 
 
    <translate 
        android:duration="500" 
        android:fromXDelta="0" 
        android:toXDelta="-100%p" /> 
 
    <alpha 
        android:duration="500" 
        android:fromAlpha="1.0" 
        android:toAlpha="0.0" /> 
 
</set> 

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