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android圖片倒影控件ReflectionImage
ReflectionImage是從android.widget.ImageView繼承而來,使用方法和其他的Android控件一樣
實現思路是從某個網站上剽竊過來的。
實現起來很簡單,詳細的解釋寫到注釋裏麵,總體思路就是在Canvas裏麵重新把原始圖片畫一次,反轉圖片用Matrix來做,透明處理實際上是加了一層漸變的蒙板.
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.Bitmap.Config;
import android.graphics.PorterDuff.Mode;
import android.graphics.Shader.TileMode;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;
import android.widget.ImageView;
public class ReflectionImage extends ImageView {
//是否為Reflection模式
private boolean mReflectionMode = true;
public ReflectionImage(Context context) {
super(context);
}
public ReflectionImage(Context context, AttributeSet attrs) {
super(context, attrs);
//取得原始圖片的bitmap並重畫
Bitmap originalImage = ((BitmapDrawable)this.getDrawable()).getBitmap();
DoReflection(originalImage);
}
public ReflectionImage(Context context, AttributeSet attrs,
int defStyle) {
super(context, attrs, defStyle);
Bitmap originalImage = ((BitmapDrawable)this.getDrawable()).getBitmap();
DoReflection(originalImage);
}
public void setReflectionMode(boolean isRef) {
mReflectionMode = isRef;
}
public boolean getReflectionMode() {
return mReflectionMode;
}
//偷懶了,隻重寫了setImageResource,和構造函數裏麵幹了同樣的事情
@Override
public void setImageResource(int resId) {
Bitmap originalImage = BitmapFactory.decodeResource(
getResources(), resId);
DoReflection(originalImage);
//super.setImageResource(resId);
}
private void DoReflection(Bitmap originalImage) {
final int reflectionGap = 4; //原始圖片和反射圖片中間的間距
int width = originalImage.getWidth();
int height = originalImage.getHeight();
//反轉
Matrix matrix = new Matrix();
matrix.preScale(1, -1);
//reflectionImage就是下麵透明的那部分,可以設置它的高度為原始的3/4,這樣效果會更好些
Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,
0, width, height, matrix, false);
//創建一個新的bitmap,高度為原來的兩倍
Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height), Config.ARGB_8888);
Canvas canvasRef = new Canvas(bitmapWithReflection);
//先畫原始的圖片
canvasRef.drawBitmap(originalImage, 0, 0, null);
//畫間距
Paint deafaultPaint = new Paint();
canvasRef.drawRect(0, height, width, height + reflectionGap, deafaultPaint);
//畫被反轉以後的圖片
canvasRef.drawBitmap(reflectionImage, 0, height + reflectionGap, null);
// 創建一個漸變的蒙版放在下麵被反轉的圖片上麵
Paint paint = new Paint();
LinearGradient shader = new LinearGradient(0,
originalImage.getHeight(), 0, bitmapWithReflection.getHeight()
+ reflectionGap, 0x80ffffff, 0x00ffffff, TileMode.CLAMP);
// Set the paint to use this shader (linear gradient)
paint.setShader(shader);
// Set the Transfer mode to be porter duff and destination in
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
// Draw a rectangle using the paint with our linear gradient
canvasRef.drawRect(0, height, width, bitmapWithReflection.getHeight()
+ reflectionGap, paint);
//調用ImageView中的setImageBitmap
this.setImageBitmap(bitmapWithReflection);
}
}
最後更新：2017-04-02 16:47:36