Android Bitmap常用代碼片段

獲取方式

        / 獲取 drawable 的圖片 可以循環 1.圖名 2.drawable 3.包名 /


    int imgid = getResources().getIdentifier("ic_launcher", "drawable", "com.example.anywight");
    text.setBackgroundResource(imgid);

    /** 通過圖片id獲得Bitmap **/
    Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);

    /** 通過 assest 獲取 獲得Drawable bitmap **/
    InputStream in = this.getAssets().open("ic_launcher");
    Drawable da = Drawable.createFromStream(in, null);
    Bitmap mm = BitmapFactory.decodeStream(in);

    /** 通過 sdcard 獲得 bitmap **/
    Bitmap bit = BitmapFactory.decodeFile("/sdcard/android.jpg");</pre> 



 常用操作 

/ view轉Bitmap /
    public static Bitmap convertViewToBitmap(View view, int bitmapWidth, int bitmapHeight) {


    Bitmap bitmap = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.ARGB_8888);
    view.draw(new Canvas(bitmap));
    return bitmap;
}

/** 將控件轉換為bitmap **/
public static Bitmap convertViewToBitMap(View view) {

    // 打開圖像緩存
    view.setDrawingCacheEnabled(true);
    // 必須調用measure和layout方法才能成功保存可視組件的截圖到png圖像文件
    // 測量View大小
    view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
    // 發送位置和尺寸到View及其所有的子View
    view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
    // 獲得可視組件的截圖
    Bitmap bitmap = view.getDrawingCache();
    return bitmap;
}

public static Bitmap getBitmapFromView(View view) {

    Bitmap returnedBitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(returnedBitmap);
    Drawable bgDrawable = view.getBackground();
    if (bgDrawable != null)
        bgDrawable.draw(canvas);
    else
        canvas.drawColor(Color.WHITE);
    view.draw(canvas);
    return returnedBitmap;
}

/** 獲取屏幕截圖的bitmap對象的代碼如下 **/
public Bitmap getScreenPic(View view) {

    View rootView = view.getRootView();
    rootView.setDrawingCacheEnabled(true);
    rootView.buildDrawingCache();
    // 不明白為什么這里返回一個空，有帖子說不能在oncreat方法中調用
    // 測量View大小
    rootView.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
    // 發送位置和尺寸到View及其所有的子View
    rootView.layout(0, 0, rootView.getMeasuredWidth(), rootView.getMeasuredHeight());
    // 解決措施，調用上面的measure和layout方法之后，返回值就不再為空
    // 如果想要創建的是固定長度和寬度的呢？
    Bitmap bitmap = rootView.getDrawingCache();
    rootView.destroyDrawingCache();
    return bitmap;
}

/** Drawable → Bitmap **/
public static Bitmap drawableToBitmap(Drawable drawable) {

    Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(),
            drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565);
    Canvas canvas = new Canvas(bitmap);
    // canvas.setBitmap(bitmap);
    drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
    drawable.draw(canvas);
    return bitmap;

}

/** bitmap → drawable **/
public static Drawable bitmapToDrawable(Context context, String filename) {

    Bitmap image = null;
    BitmapDrawable ddd = null;
    try {
        AssetManager am = context.getAssets();
        InputStream is = am.open(filename);
        image = BitmapFactory.decodeStream(is);
        ddd = new BitmapDrawable(context.getResources(), image);
        is.close();
    } catch (Exception e) {
    }
    return ddd;

}

/** byte[] → Bitmap **/
public static Bitmap byteToDrawable(Context context, byte[] bb) {

    Bitmap pp = BitmapFactory.decodeByteArray(bb, 0, bb.length);
    return pp;
}

/** Bitmap → byte[] **/
public static byte[] bitmapToByte(Bitmap bitmap) {

    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
    byte[] yy = baos.toByteArray();
    return yy;
}

/** 將text 轉換成 bitmap **/
public static Bitmap createTxtImage(String txt, int txtSize) {

    Bitmap mbmpTest = Bitmap.createBitmap(txt.length() * txtSize + 4, txtSize + 4, Config.ARGB_8888);
    Canvas canvasTemp = new Canvas(mbmpTest);
    Paint p = new Paint();
    p.setAntiAlias(true);
    p.setColor(Color.WHITE);
    p.setTextSize(txtSize);
    canvasTemp.drawText(txt, 2, txtSize - 2, p);
    return mbmpTest;

}

/** 顯示將bitmap進行縮放 **/
public Bitmap bitmapScanel(Context context) {

    // 通過openRawResource獲取一個inputStream對象
    InputStream inputStream = context.getResources().openRawResource(R.id.backageground);
    // 通過一個InputStream創建一個BitmapDrawable對象
    BitmapDrawable drawable = new BitmapDrawable(inputStream);
    // 通過BitmapDrawable對象獲得Bitmap對象
    Bitmap bitmap = drawable.getBitmap();
    // 利用Bitmap對象創建縮略圖
    bitmap = ThumbnailUtils.extractThumbnail(bitmap, 40, 40);
    return bitmap;

}

/** 放大縮小圖片 **/
public static Bitmap zoomBitmap(Bitmap bitmap, int w, int h) {

    int width = bitmap.getWidth();
    int height = bitmap.getHeight();
    Matrix matrix = new Matrix();
    float scaleWidht = ((float) w / width);
    float scaleHeight = ((float) h / height);
    matrix.postScale(scaleWidht, scaleHeight);
    Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);
    return newbmp;
}

/** 獲得圓角圖片的方法 **/
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;
}

/** 對 bitmap 進行裁剪 **/
public Bitmap bitmapClip(Context context, int id, int x, int y) {

    Bitmap map = BitmapFactory.decodeResource(context.getResources(), id);
    map = Bitmap.createBitmap(map, x, y, 120, 120);
    return map;
}

/**
 * 圖片的倒影效果
 */
public static Bitmap createReflectedImage(Bitmap originalImage) {

    final int reflectionGap = 4;

    int width = originalImage.getWidth();
    int height = originalImage.getHeight();

    Matrix matrix = new Matrix();
    matrix.preScale(1, -1);

    // Create a Bitmap with the flip matrix applied to it.
    // We only want the bottom half of the image
    Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0, height / 2, width, height / 2, matrix, false);

    // Create a new bitmap with same width but taller to fit reflection
    Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height / 2), Config.ARGB_8888);

    // Create a new Canvas with the bitmap that's big enough for
    // the image plus gap plus reflection
    Canvas canvas = new Canvas(bitmapWithReflection);
    // Draw in the original image
    canvas.drawBitmap(originalImage, 0, 0, null);
    // Draw in the gap
    Paint defaultPaint = new Paint();
    canvas.drawRect(0, height, width, height + reflectionGap, defaultPaint);
    // Draw in the reflection
    canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);

    // Create a shader that is a linear gradient that covers the reflection
    Paint paint = new Paint();
    LinearGradient shader = new LinearGradient(0, originalImage.getHeight(), 0, bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff, 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
    canvas.drawRect(0, height, width, bitmapWithReflection.getHeight() + reflectionGap, paint);

    return bitmapWithReflection;
}</pre>