Android之图片工具类ImageUtil

package com.android.myimageutil;import android.content.Context;import android.content.res.Resources;import android.graphics.Bitmap;import android.graphics.Bitmap.Config;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.LinearGradient;import android.graphics.Matrix;import android.graphics.Paint;import android.graphics.PixelFormat;import android.graphics.PorterDuff.Mode;import android.graphics.PorterDuffXfermode;import android.graphics.Rect;import android.graphics.RectF;import android.graphics.Shader.TileMode;import android.graphics.drawable.Drawable;public class ImageUtil {    /**     *  放大缩小图片     * @param bitmap 要放大的图片     * @param dstWidth 目标宽     * @param dstHeight 目标高     * @return     */    public static Bitmap zoomBitmap(Bitmap bitmap, int dstWidth, int dstHeight) {        int width = bitmap.getWidth();        int height = bitmap.getHeight();        Matrix matrix = new Matrix();        float scaleWidht = ((float) dstWidth / width);        float scaleHeight = ((float) dstHeight / height);        matrix.postScale(scaleWidht, scaleHeight);        Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height,                matrix, true);        return newbmp;    }    /**     * 将Drawable转化为Bitmap     * @param drawable     * @return     */    public static Bitmap drawableToBitmap(Drawable drawable) {        int width = drawable.getIntrinsicWidth();        int height = drawable.getIntrinsicHeight();        Bitmap bitmap = Bitmap.createBitmap(width, height, drawable                .getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888                : Bitmap.Config.RGB_565);        Canvas canvas = new Canvas(bitmap);        drawable.setBounds(0, 0, width, height);        drawable.draw(canvas);        return bitmap;    }    /**     * 获得圆角图片的方法     * @param bitmap     * @param roundPx  4脚幅度     * @return     */    public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, float roundPx) {        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),                bitmap.getHeight(), Config.ARGB_8888);        Canvas canvas = new Canvas(output);        final int color = 0xff424242;        final Paint paint = new Paint();        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());        final RectF rectF = new RectF(rect);        paint.setAntiAlias(true);        canvas.drawARGB(0, 0, 0, 0);        paint.setColor(color);        canvas.drawRoundRect(rectF, roundPx, roundPx, paint);        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));        canvas.drawBitmap(bitmap, rect, rect, paint);        return output;    }    /**     * 获得带倒影的图片方法     * @param bitmap     * @return     */    public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap) {        final int reflectionGap = 4;        int width = bitmap.getWidth();        int height = bitmap.getHeight();        Matrix matrix = new Matrix();        matrix.preScale(1, -1);        Bitmap reflectionImage = Bitmap.createBitmap(bitmap, 0, height / 2,                width, height / 2, matrix, false);        Bitmap bitmapWithReflection = Bitmap.createBitmap(width,                (height + height / 2), Config.ARGB_8888);        Canvas canvas = new Canvas(bitmapWithReflection);        canvas.drawBitmap(bitmap, 0, 0, null);        Paint deafalutPaint = new Paint();        canvas.drawRect(0, height, width, height + reflectionGap, deafalutPaint);        canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);        Paint paint = new Paint();        LinearGradient shader = new LinearGradient(0, bitmap.getHeight(), 0,                bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff,                0x00ffffff, TileMode.CLAMP);        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        canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()                + reflectionGap, paint);        return bitmapWithReflection;    }    /**     * 添加文字到图片，类似水印文字。     * @param gContext     * @param gResId     * @param gText     * @return     */    public static Bitmap drawTextToBitmap(Context gContext, int gResId, String gText) {        Resources resources = gContext.getResources();        float scale = resources.getDisplayMetrics().density;        Bitmap bitmap = BitmapFactory.decodeResource(resources, gResId);        android.graphics.Bitmap.Config bitmapConfig = bitmap.getConfig();        // set default bitmap config if none        if (bitmapConfig == null) {            bitmapConfig = android.graphics.Bitmap.Config.ARGB_8888;        }        // resource bitmaps are imutable,        // so we need to convert it to mutable one        bitmap = bitmap.copy(bitmapConfig, true);        Canvas canvas = new Canvas(bitmap);        // new antialised Paint        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);        // text color - #3D3D3D        paint.setColor(Color.rgb(61, 61, 61));        // text size in pixels        paint.setTextSize((int) (14 * scale*5));        // text shadow        paint.setShadowLayer(1f, 0f, 1f, Color.WHITE);        // draw text to the Canvas center        Rect bounds = new Rect();        paint.getTextBounds(gText, 0, gText.length(), bounds);        //draw  text  to the bottom        int x = (bitmap.getWidth() - bounds.width())/10*9 ;        int y = (bitmap.getHeight() + bounds.height())/10*9;        canvas.drawText(gText, x , y, paint);        return bitmap;    }}