自定义控件-----MagnifyingGlass

其实也不能叫自定义控件了,只是一个图片放大镜而已

 

本来想像iphone的放大镜那样,点下鼠标,鼠标所在的位置就被放大,但是没成功

先暂时就放大图片了,以后有其他的思路了再把这个想法用到其他控件上面

 

 

这个东西问题多多,先暂时备份到这里,以后有时间了再来改进

 

 

 

简单说下实现思路,其实就是两张完全一样的图片重叠起来,上面那一张默认情况下是不可见的,当点下鼠标的时候,以鼠标所在的点为远点,把上面那张图片放大1.5倍,然后显示出来(当然只显示一个圆形的区域就可以了),当鼠标移动的时候重新计算位置,显示出相应部分被放大的图片

有一些问题,但是暂时没想到其他更好的实现方法

 

package com.myview; import android.content.Context; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Path; import android.graphics.Region; import android.util.AttributeSet; import android.util.Log; import android.view.MotionEvent; import android.view.animation.Animation; import android.view.animation.ScaleAnimation; import android.widget.AbsoluteLayout; import android.widget.ImageView; @SuppressWarnings("deprecation") public class MagnifyingGlass extends AbsoluteLayout { private int mRescourceID; private Context mContext; private ImageView v = null; private MView mv = null; private int mRadio; public MagnifyingGlass(Context context) { super(context); mContext = context; } public MagnifyingGlass(Context context, AttributeSet attrs) { super(context, attrs); mContext = context; } public MagnifyingGlass(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); mContext = context; } public void setRadio(int r) { mRadio = r; if(mv != null) { mv.setRadio(r); } } public int getRadio() { return mRadio; } public void setImageResID(int id) { mRescourceID = id; initView(mContext); } private void initView(Context context) { v = new ImageView(context); mv = new MView(context); v.setImageResource(mRescourceID); mv.setImageResource(mRescourceID); Log.e("mv", "!~!!!!!!null~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"); mv.setRadio(getRadio()); this.addView(v, LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT); this.addView(mv, LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT); } private class MView extends ImageView { private boolean mMMode = false; private float mX; private float mY; private int mRadio; Paint mPaint = new Paint(); Path mPath = new Path(); public MView(Context context) { super(context); initView(); } private void initView() { mRadio = 75; Animation scaleAnime = new ScaleAnimation(1.0f, 1.5f, 1.0f, 1.5f, 0, 0); scaleAnime.setStartOffset(0); scaleAnime.setFillAfter(true); this.startAnimation(scaleAnime); } public void setRadio(int r) { if (r <=10) mRadio = 75; else mRadio = r; } @Override public boolean onTouchEvent(MotionEvent event) { mX = event.getX(); mY = event.getY(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: mMMode = true; this.invalidate(); break; case MotionEvent.ACTION_UP: mMMode = false; this.invalidate(); break; case MotionEvent.ACTION_MOVE: this.invalidate(); break; } return true; //return super.onTouchEvent(event); } @Override protected void onDraw(Canvas canvas) { if (mMMode) { mPaint.setAntiAlias(true); mPaint.setStrokeWidth(6); //Draw circle and clip. canvas.save(); mPath.reset(); canvas.clipPath(mPath); // makes the clip empty mPath.addCircle(mX-mX/3, mY-mY/3, mRadio, Path.Direction.CCW); canvas.clipPath(mPath, Region.Op.REPLACE); canvas.translate(-mX/3, -mY/3); // move the canvas to fit the center. super.onDraw(canvas); canvas.restore(); } } } }  

代码很简单了,不解释了,看看就行了

 

用法就很简单了

public class HelloAndroid extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); MagnifyingGlass mg = (MagnifyingGlass)this.findViewById(R.id.mg); mg.setRadio(50); mg.setImageResID(R.drawable.f); } } 

 

<?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" > <!-- <com.myview.ReflectionImage--> <!-- android:id="@+android:id/ri"--> <!-- android:layout_width="wrap_content" --> <!-- android:layout_height="wrap_content"--> <!-- android:src="@drawable/froyoandroid">--> <!-- </com.myview.ReflectionImage>--> <com.myview.MagnifyingGlass android:id="@+id/mg" android:layout_width="fill_parent" android:layout_height="fill_parent" /> </LinearLayout>