我正在尝试使图像的底部像图像中一样模糊，以便顶部的 View 。
我尝试使用 Rendenscript 对其进行模糊处理，但我无法仅对 View 后面的部分进行模糊处理。 :(
我见过很多图书馆，但几乎所有图书馆都模糊了整个图像，但不是图像的一部分。
此外，一个重要的部分是我在 ViewPager 中使用它，因此需要像 this in IOS 这样的快速和动态的东西。当它背后的图像发生变化时，它会重新绘制自己。
感谢任何帮助。感谢您的光临!
我的 xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center"
android:orientation="vertical" >
<ImageView
android:id="@+id/image"
android:src="@drawable/broadstairs"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
android:layout_centerInParent="true"/>
<TextView
android:id="@+id/text"
android:layout_width="match_parent"
android:layout_height="200dp"
android:text="Hello World"
android:gravity="center"
android:layout_alignParentBottom="true"
android:textColor="@android:color/white"
android:textStyle="bold"
android:textSize="36sp"/>
</RelativeLayout>
我的代码:
模糊生成器.java
public class BlurBuilder {
private static final float BITMAP_SCALE = 0.1f;
private static final float BLUR_RADIUS = 7.5f;
public static Bitmap blur(Context context, Bitmap image) {
int width = Math.round(image.getWidth() * BITMAP_SCALE);
int height = Math.round(image.getHeight() * BITMAP_SCALE);
Bitmap inputBitmap = Bitmap.createScaledBitmap(image, width, height, false);
Bitmap outputBitmap = Bitmap.createBitmap(inputBitmap);
RenderScript rs = RenderScript.create(context);
ScriptIntrinsicBlur theIntrinsic = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
Allocation tmpIn = Allocation.createFromBitmap(rs, inputBitmap);
Allocation tmpOut = Allocation.createFromBitmap(rs, outputBitmap);
theIntrinsic.setRadius(BLUR_RADIUS);
theIntrinsic.setInput(tmpIn);
theIntrinsic.forEach(tmpOut);
tmpOut.copyTo(outputBitmap);
return outputBitmap;
}
@SuppressLint("NewApi")
public static void blur(final Context context, final Bitmap bitmap, final View view) {
new AsyncTask<Void, Void, Bitmap>() {
@Override
protected Bitmap doInBackground(Void... params) {
Paint paint = new Paint();
paint.setFilterBitmap(true);
Bitmap cropImage = Bitmap.createBitmap(bitmap, 0, bitmap.getHeight() - view.getHeight(), bitmap.getWidth(), view.getHeight());
return BlurBuilder.blur(context, cropImage);
}
@Override
protected void onPostExecute(Bitmap bitmap) {
super.onPostExecute(bitmap);
if (bitmap != null) {
int sdk = android.os.Build.VERSION.SDK_INT;
if (sdk < android.os.Build.VERSION_CODES.JELLY_BEAN) {
view.setBackgroundDrawable(new BitmapDrawable(context.getResources(), bitmap));
} else {
view.setBackground(new BitmapDrawable(context.getResources(), bitmap));
}
}
}
}.execute();
}
}
在我的 MainActivity 的 onCreate 中，我这样做:
BlurBuilder.blur(BitmapActivity.this, ((BitmapDrawable) mView.getDrawable()).getBitmap(), mDummyView);
结果如下:
最佳答案
将这两个类添加到您的应用中，
1> BlurKit.Java
public class BlurKit {
private static BlurKit instance;
private RenderScript rs;
public static void init(Context context) {
if (instance != null) {
return;
}
instance = new BlurKit();
instance.rs = RenderScript.create(context);
}
public Bitmap blur(Bitmap src, int radius) {
final Allocation input = Allocation.createFromBitmap(rs, src);
final Allocation output = Allocation.createTyped(rs, input.getType());
final ScriptIntrinsicBlur script;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.JELLY_BEAN_MR1) {
script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
script.setRadius(radius);
script.setInput(input);
script.forEach(output);
}
output.copyTo(src);
return src;
}
public Bitmap blur(View src, int radius) {
Bitmap bitmap = getBitmapForView(src, 1f);
return blur(bitmap, radius);
}
public Bitmap fastBlur(View src, int radius, float downscaleFactor) {
Bitmap bitmap = getBitmapForView(src, downscaleFactor);
return blur(bitmap, radius);
}
private Bitmap getBitmapForView(View src, float downscaleFactor) {
Bitmap bitmap = Bitmap.createBitmap(
(int) (src.getWidth() * downscaleFactor),
(int) (src.getHeight() * downscaleFactor),
Bitmap.Config.ARGB_4444
);
Canvas canvas = new Canvas(bitmap);
Matrix matrix = new Matrix();
matrix.preScale(downscaleFactor, downscaleFactor);
canvas.setMatrix(matrix);
src.draw(canvas);
return bitmap;
}
public static BlurKit getInstance() {
if (instance == null) {
throw new RuntimeException("BlurKit not initialized!");
}
return instance;
}
}
2>BlurLayout.Java
public class BlurLayout extends FrameLayout {
public static final float DEFAULT_DOWNSCALE_FACTOR = 0.12f;
public static final int DEFAULT_BLUR_RADIUS = 12;
public static final int DEFAULT_FPS = 60;
// Customizable attributes
/** Factor to scale the view bitmap with before blurring. */
private float mDownscaleFactor;
/** Blur radius passed directly to stackblur library. */
private int mBlurRadius;
/** Number of blur invalidations to do per second. */
private int mFPS;
// Calculated class dependencies
/** Reference to View for top-parent. For retrieval see {@link #getActivityView() getActivityView}. */
private WeakReference<View> mActivityView;
public BlurLayout(Context context) {
super(context, null);
}
public BlurLayout(Context context, AttributeSet attrs) {
super(context, attrs);
BlurKit.init(context);
TypedArray a = context.getTheme().obtainStyledAttributes(
attrs,
R.styleable.BlurLayout,
0, 0);
try {
mDownscaleFactor = a.getFloat(R.styleable.BlurLayout_downscaleFactor, DEFAULT_DOWNSCALE_FACTOR);
mBlurRadius = a.getInteger(R.styleable.BlurLayout_blurRadius, DEFAULT_BLUR_RADIUS);
mFPS = a.getInteger(R.styleable.BlurLayout_fps, DEFAULT_FPS);
} finally {
a.recycle();
}
if (mFPS > 0) {
Choreographer.getInstance().postFrameCallback(invalidationLoop);
}
}
/** Choreographer callback that re-draws the blur and schedules another callback. */
private Choreographer.FrameCallback invalidationLoop = new Choreographer.FrameCallback() {
@Override
public void doFrame(long frameTimeNanos) {
invalidate();
Choreographer.getInstance().postFrameCallbackDelayed(this, 1000 / mFPS);
}
};
/**
* {@inheritDoc}
*/
@Override
public void invalidate() {
super.invalidate();
Bitmap bitmap = blur();
if (bitmap != null) {
setBackground(new BitmapDrawable(bitmap));
}
}
/**
* Recreates blur for content and sets it as the background.
*/
private Bitmap blur() {
if (getContext() == null) {
return null;
}
// Check the reference to the parent view.
// If not available, attempt to make it.
if (mActivityView == null || mActivityView.get() == null) {
mActivityView = new WeakReference<>(getActivityView());
if (mActivityView.get() == null) {
return null;
}
}
// Calculate the relative point to the parent view.
Point pointRelativeToActivityView = getPositionInScreen();
// Set alpha to 0 before creating the parent view bitmap.
// The blur view shouldn't be visible in the created bitmap.
setAlpha(0);
// Screen sizes for bound checks
int screenWidth = mActivityView.get().getWidth();
int screenHeight = mActivityView.get().getHeight();
// The final dimensions of the blurred bitmap.
int width = (int) (getWidth() * mDownscaleFactor);
int height = (int) (getHeight() * mDownscaleFactor);
// The X/Y position of where to crop the bitmap.
int x = (int) (pointRelativeToActivityView.x * mDownscaleFactor);
int y = (int) (pointRelativeToActivityView.y * mDownscaleFactor);
// Padding to add to crop pre-blur.
// Blurring straight to edges has side-effects so padding is added.
int xPadding = getWidth() / 8;
int yPadding = getHeight() / 8;
// Calculate padding independently for each side, checking edges.
int leftOffset = -xPadding;
leftOffset = x + leftOffset >= 0 ? leftOffset : 0;
int rightOffset = xPadding;
rightOffset = x + getWidth() + rightOffset <= screenWidth ? rightOffset : screenWidth - getWidth() - x;
int topOffset = -yPadding;
topOffset = y + topOffset >= 0 ? topOffset : 0;
int bottomOffset = yPadding;
bottomOffset = y + height + bottomOffset <= screenHeight ? bottomOffset : 0;
// Create parent view bitmap, cropped to the BlurLayout area with above padding.
Bitmap bitmap;
try {
bitmap = getDownscaledBitmapForView(
mActivityView.get(),
new Rect(
pointRelativeToActivityView.x + leftOffset,
pointRelativeToActivityView.y + topOffset,
pointRelativeToActivityView.x + getWidth() + Math.abs(leftOffset) + rightOffset,
pointRelativeToActivityView.y + getHeight() + Math.abs(topOffset) + bottomOffset
),
mDownscaleFactor
);
} catch (NullPointerException e) {
return null;
}
// Blur the bitmap.
bitmap = BlurKit.getInstance().blur(bitmap, mBlurRadius);
//Crop the bitmap again to remove the padding.
bitmap = Bitmap.createBitmap(
bitmap,
(int) (Math.abs(leftOffset) * mDownscaleFactor),
(int) (Math.abs(topOffset) * mDownscaleFactor),
width,
height
);
// Make self visible again.
setAlpha(1);
// Set background as blurred bitmap.
return bitmap;
}
/**
* Casts context to Activity and attempts to create a view reference using the window decor view.
* @return View reference for whole activity.
*/
private View getActivityView() {
Activity activity;
try {
activity = (Activity) getContext();
} catch (ClassCastException e) {
return null;
}
return activity.getWindow().getDecorView().findViewById(android.R.id.content);
}
/**
* Returns the position in screen. Left abstract to allow for specific implementations such as
* caching behavior.
*/
private Point getPositionInScreen() {
return getPositionInScreen(this);
}
/**
* Finds the Point of the parent view, and offsets result by self getX() and getY().
* @return Point determining position of the passed in view inside all of its ViewParents.
*/
private Point getPositionInScreen(View view) {
if (getParent() == null) {
return new Point();
}
ViewGroup parent;
try {
parent = (ViewGroup) view.getParent();
} catch (Exception e) {
return new Point();
}
if (parent == null) {
return new Point();
}
Point point = getPositionInScreen(parent);
point.offset((int) view.getX(), (int) view.getY());
return point;
}
/**
* Users a View reference to create a bitmap, and downscales it using the passed in factor.
* Uses a Rect to crop the view into the bitmap.
* @return Bitmap made from view, downscaled by downscaleFactor.
* @throws NullPointerException
*/
private Bitmap getDownscaledBitmapForView(View view, Rect crop, float downscaleFactor) throws NullPointerException {
View screenView = view.getRootView();
int width = (int) (crop.width() * downscaleFactor);
int height = (int) (crop.height() * downscaleFactor);
if (screenView.getWidth() <= 0 || screenView.getHeight() <= 0 || width <= 0 || height <= 0) {
throw new NullPointerException();
}
float dx = -crop.left * downscaleFactor;
float dy = -crop.top * downscaleFactor;
Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_4444);
Canvas canvas = new Canvas(bitmap);
Matrix matrix = new Matrix();
matrix.preScale(downscaleFactor, downscaleFactor);
matrix.postTranslate(dx, dy);
canvas.setMatrix(matrix);
screenView.draw(canvas);
return bitmap;
}
/**
* Sets downscale factor to use pre-blur.
* See {@link #mDownscaleFactor}.
*/
public void setDownscaleFactor(float downscaleFactor) {
this.mDownscaleFactor = downscaleFactor;
invalidate();
}
/**
* Sets blur radius to use on downscaled bitmap.
* See {@link #mBlurRadius}.
*/
public void setBlurRadius(int blurRadius) {
this.mBlurRadius = blurRadius;
invalidate();
}
/**
* Sets FPS to invalidate blur with.
* See {@link #mFPS}.
*/
public void setFPS(int fps) {
this.mFPS = fps;
}
}
在 XML 文件中:
<FrameLayout
android:id="@+id/fl_uploadedView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="@dimen/_10sdp">
<ImageView
android:id="@+id/dv_uploadedPic"
android:layout_width="match_parent"
android:layout_height="@dimen/_150sdp"
android:contentDescription="@string/app_name"
android:scaleType="centerCrop"
android:src="@color/gray" />
<BlurLayout
android:id="@+id/ll_blurView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom">
<TextView
android:id="@+id/tv_fileName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="left"
android:padding="@dimen/_5sdp"
android:textSize="@dimen/_10sdp"
/>
</BlurLayout>
</FrameLayout>
不要忘记将其添加到 值> attr.xml
<!--
Blur Layout start
-->
<declare-styleable name="BlurLayout">
<attr name="downscaleFactor" format="float" />
<attr name="blurRadius" format="integer" />
<attr name="fps" format="integer" />
</declare-styleable>
<!--
Blur Layout end
-->
关于Android Blur View(模糊 View 后面的背景)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31808955/