Android 带有阴影的自定义ImageView
好吧，我一直在阅读和四处搜索，现在我的头撞在墙上试图弄明白这一点。以下是我目前掌握的情况：Android 带有阴影的自定义ImageView,android,overriding,imageview,dropshadow,Android,Overriding,Imageview,Dropshadow,好吧，我一直在阅读和四处搜索，现在我的头撞在墙上试图弄明白这一点。以下是我目前掌握的情况： package com.pockdroid.sandbox; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Rect; import android.w
package com.pockdroid.sandbox;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.widget.ImageView;
public class ShadowImageView extends ImageView {
private Rect mRect;
private Paint mPaint;
public ShadowImageView(Context context)
{
super(context);
mRect = new Rect();
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setShadowLayer(2f, 1f, 1f, Color.BLACK);
}
@Override
protected void onDraw(Canvas canvas)
{
Rect r = mRect;
Paint paint = mPaint;
canvas.drawRect(r, paint);
super.onDraw(canvas);
}
@Override
protected void onMeasure(int w, int h)
{
super.onMeasure(w,h);
int mH, mW;
mW = getSuggestedMinimumWidth() < getMeasuredWidth()? getMeasuredWidth() : getSuggestedMinimumWidth();
mH = getSuggestedMinimumHeight() < getMeasuredHeight()? getMeasuredHeight() : getSuggestedMinimumHeight();
setMeasuredDimension(mW + 5, mH + 5);
}
编辑：所以我在IRC频道和Romanguy谈了一些，我现在用下面的代码处理普通的矩形图像。它仍然不会直接将阴影绘制到位图的透明度上，所以我仍在努力
@Override
protected void onDraw(Canvas canvas)
{
Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.omen);
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setShadowLayer(5.5f, 6.0f, 6.0f, Color.BLACK);
canvas.drawColor(Color.GRAY);
canvas.drawRect(50, 50, 50 + bmp.getWidth(), 50 + bmp.getHeight(), paint);
canvas.drawBitmap(bmp, 50, 50, null);
}
给你。以xml静态或代码动态设置ImageView的源 这里的影子是白色的
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content" android:layout_height="wrap_content">
<View android:layout_width="wrap_content" android:layout_height="wrap_content"
android:background="@android:color/white" android:layout_alignLeft="@+id/image"
android:layout_alignRight="@id/image" android:layout_alignTop="@id/image"
android:layout_alignBottom="@id/image" android:layout_marginLeft="10dp"
android:layout_marginBottom="10dp" />
<ImageView android:id="@id/image" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:src="..."
android:padding="5dp" />
</RelativeLayout>
这是罗曼·盖伊在Devxx的演讲，pdf格式 希望这有帮助 注释
setLayerType（LAYER\u TYPE\u软件，mShadow）SetShadowLayer好吧，我不认为这一个会有更多的答案，所以我现在要做的只是一个矩形图像的解决方案。我使用了以下九个匹配：
以及XML中的适当填充：
<ImageView
android:id="@+id/image_test"
android:background="@drawable/drop_shadow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingLeft="6px"
android:paddingTop="4px"
android:paddingRight="8px"
android:paddingBottom="9px"
android:src="@drawable/pic1"
/>
不太理想，但它可以。我使用这段代码成功地应用了渐变边框
public static Bitmap drawShadow(Bitmap bitmap, int leftRightThk, int bottomThk, int padTop) {
int w = bitmap.getWidth();
int h = bitmap.getHeight();
int newW = w - (leftRightThk * 2);
int newH = h - (bottomThk + padTop);
Bitmap.Config conf = Bitmap.Config.ARGB_8888;
Bitmap bmp = Bitmap.createBitmap(w, h, conf);
Bitmap sbmp = Bitmap.createScaledBitmap(bitmap, newW, newH, false);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
Canvas c = new Canvas(bmp);
// Left
int leftMargin = (leftRightThk + 7)/2;
Shader lshader = new LinearGradient(0, 0, leftMargin, 0, Color.TRANSPARENT, Color.BLACK, TileMode.CLAMP);
paint.setShader(lshader);
c.drawRect(0, padTop, leftMargin, newH, paint);
// Right
Shader rshader = new LinearGradient(w - leftMargin, 0, w, 0, Color.BLACK, Color.TRANSPARENT, TileMode.CLAMP);
paint.setShader(rshader);
c.drawRect(newW, padTop, w, newH, paint);
// Bottom
Shader bshader = new LinearGradient(0, newH, 0, bitmap.getHeight(), Color.BLACK, Color.TRANSPARENT, TileMode.CLAMP);
paint.setShader(bshader);
c.drawRect(leftMargin -3, newH, newW + leftMargin + 3, bitmap.getHeight(), paint);
c.drawBitmap(sbmp, leftRightThk, 0, null);
return bmp;
}
public class ShadowImage extends Drawable {
Bitmap bm;
@Override
public void draw(Canvas canvas) {
Paint mShadow = new Paint();
Rect rect = new Rect(0,0,bm.getWidth(), bm.getHeight());
mShadow.setAntiAlias(true);
mShadow.setShadowLayer(5.5f, 4.0f, 4.0f, Color.BLACK);
canvas.drawRect(rect, mShadow);
canvas.drawBitmap(bm, 0.0f, 0.0f, null);
}
public ShadowImage(Bitmap bitmap) {
super();
this.bm = bitmap;
} ... }
private static Bitmap getDropShadow3(Bitmap bitmap) {
if (bitmap==null) return null;
int think = 6;
int w = bitmap.getWidth();
int h = bitmap.getHeight();
int newW = w - (think);
int newH = h - (think);
Bitmap.Config conf = Bitmap.Config.ARGB_8888;
Bitmap bmp = Bitmap.createBitmap(w, h, conf);
Bitmap sbmp = Bitmap.createScaledBitmap(bitmap, newW, newH, false);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
Canvas c = new Canvas(bmp);
// Right
Shader rshader = new LinearGradient(newW, 0, w, 0, Color.GRAY, Color.LTGRAY, Shader.TileMode.CLAMP);
paint.setShader(rshader);
c.drawRect(newW, think, w, newH, paint);
// Bottom
Shader bshader = new LinearGradient(0, newH, 0, h, Color.GRAY, Color.LTGRAY, Shader.TileMode.CLAMP);
paint.setShader(bshader);
c.drawRect(think, newH, newW , h, paint);
//Corner
Shader cchader = new LinearGradient(0, newH, 0, h, Color.LTGRAY, Color.LTGRAY, Shader.TileMode.CLAMP);
paint.setShader(cchader);
c.drawRect(newW, newH, w , h, paint);
c.drawBitmap(sbmp, 0, 0, null);
return bmp;
}
我相信这个答案来自
以下是s答案的实现： 待办事项：
执行
setLayerType（图层类型软件，mShadow）仅当API级别>10时我已在上面的答案基础上构建--在所有方面创建阴影
private static final int GRAY_COLOR_FOR_SHADE = Color.argb(50, 79, 79, 79);
// this method takes a bitmap and draws around it 4 rectangles with gradient to create a
// shadow effect.
public static Bitmap addShadowToBitmap(Bitmap origBitmap) {
int shadowThickness = 13; // can be adjusted as needed
int bmpOriginalWidth = origBitmap.getWidth();
int bmpOriginalHeight = origBitmap.getHeight();
int bigW = bmpOriginalWidth + shadowThickness * 2; // getting dimensions for a bigger bitmap with margins
int bigH = bmpOriginalHeight + shadowThickness * 2;
Bitmap containerBitmap = Bitmap.createBitmap(bigW, bigH, Bitmap.Config.ARGB_8888);
Bitmap copyOfOrigBitmap = Bitmap.createScaledBitmap(origBitmap, bmpOriginalWidth, bmpOriginalHeight, false);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
Canvas canvas = new Canvas(containerBitmap); // drawing the shades on the bigger bitmap
//right shade - direction of gradient is positive x (width)
Shader rightShader = new LinearGradient(bmpOriginalWidth, 0, bigW, 0, GRAY_COLOR_FOR_SHADE,
Color.TRANSPARENT, Shader.TileMode.CLAMP);
paint.setShader(rightShader);
canvas.drawRect(bigW - shadowThickness, shadowThickness, bigW, bigH - shadowThickness, paint);
//bottom shade - direction is positive y (height)
Shader bottomShader = new LinearGradient(0, bmpOriginalHeight, 0, bigH, GRAY_COLOR_FOR_SHADE,
Color.TRANSPARENT, Shader.TileMode.CLAMP);
paint.setShader(bottomShader);
canvas.drawRect(shadowThickness, bigH - shadowThickness, bigW - shadowThickness, bigH, paint);
//left shade - direction is negative x
Shader leftShader = new LinearGradient(shadowThickness, 0, 0, 0, GRAY_COLOR_FOR_SHADE,
Color.TRANSPARENT, Shader.TileMode.CLAMP);
paint.setShader(leftShader);
canvas.drawRect(0, shadowThickness, shadowThickness, bigH - shadowThickness, paint);
//top shade - direction is negative y
Shader topShader = new LinearGradient(0, shadowThickness, 0, 0, GRAY_COLOR_FOR_SHADE,
Color.TRANSPARENT, Shader.TileMode.CLAMP);
paint.setShader(topShader);
canvas.drawRect(shadowThickness, 0, bigW - shadowThickness, shadowThickness, paint);
// starting to draw bitmap not from 0,0 to get margins for shade rectangles
canvas.drawBitmap(copyOfOrigBitmap, shadowThickness, shadowThickness, null);
return containerBitmap;
}
根据需要更改常量中的颜色。使用此类在位图上绘制阴影
public class ShadowGenerator {
// Percent of actual icon size
private static final float HALF_DISTANCE = 0.5f;
public static final float BLUR_FACTOR = 0.5f/48;
// Percent of actual icon size
private static final float KEY_SHADOW_DISTANCE = 1f/48;
public static final int KEY_SHADOW_ALPHA = 61;
public static final int AMBIENT_SHADOW_ALPHA = 30;
private static final Object LOCK = new Object();
// Singleton object guarded by {@link #LOCK}
private static ShadowGenerator sShadowGenerator;
private int mIconSize;
private final Canvas mCanvas;
private final Paint mBlurPaint;
private final Paint mDrawPaint;
private final Context mContext;
private ShadowGenerator(Context context) {
mContext = context;
mIconSize = Utils.convertDpToPixel(context,63);
mCanvas = new Canvas();
mBlurPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
mBlurPaint.setMaskFilter(new BlurMaskFilter(mIconSize * BLUR_FACTOR, Blur.NORMAL));
mDrawPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
}
public synchronized Bitmap recreateIcon(Bitmap icon) {
mIconSize = Utils.convertDpToPixel(mContext,3)+icon.getWidth();
int[] offset = new int[2];
Bitmap shadow = icon.extractAlpha(mBlurPaint, offset);
Bitmap result = Bitmap.createBitmap(mIconSize, mIconSize, Config.ARGB_8888);
mCanvas.setBitmap(result);
// Draw ambient shadow
mDrawPaint.setAlpha(AMBIENT_SHADOW_ALPHA);
mCanvas.drawBitmap(shadow, offset[0], offset[1], mDrawPaint);
// Draw key shadow
mDrawPaint.setAlpha(KEY_SHADOW_ALPHA);
mCanvas.drawBitmap(shadow, offset[0], offset[1] + KEY_SHADOW_DISTANCE * mIconSize, mDrawPaint);
// Draw the icon
mDrawPaint.setAlpha(255);
mCanvas.drawBitmap(icon, 0, 0, mDrawPaint);
mCanvas.setBitmap(null);
return result;
}
public static ShadowGenerator getInstance(Context context) {
synchronized (LOCK) {
if (sShadowGenerator == null) {
sShadowGenerator = new ShadowGenerator(context);
}
}
return sShadowGenerator;
}
}
如果您想使用自定义imageView，我建议您使用
视图看起来很完美，不要使用任何九路径图像
绝对不是我想要的。我想要一个实际渲染的阴影，逐渐变为透明；这只会在我的图片后面给我一个白色的框。@kcopock-没有必要否决这个答案-它真的没那么糟糕。我以后一定会尝试！谢谢你的PDF，看起来很有趣。此演示视频是否可在线观看？不要忘记蜂巢及以上版本调用setLayerType（LAYER_TYPE_软件，mShadow）。否则，您将看不到您的阴影。不幸的是，setShadowLayer不能与硬件加速一起工作。您也可以对形状应用绘画，因此阴影层对它们有效。但是，它不会应用于形状中的内部“孔”。Devxx链接已经失效“它现在正在为普通矩形图像工作”。。。所以它不适用于非矩形图像，然后我假设它也不适用于9patch图像，对吗？你让它工作了吗？因为Romain Guy的方法在我的测试中还不适用。嗯，有趣的问题。我想你可能会采取你的观点，使用9面片，把它包装成一个框架布局，给框架布局以阴影9面片的背景。但是是的，它只适用于矩形图像，因为9面片无法跟随透明轮廓。不幸的是，我还没有找到更好的解决方案，但是，从那以后我就再也没有尝试过。别忘了将png保存为drop_shadow.9.png.Wow，我花了太多时间在代码中尝试。更优雅的解决方案！那需要调整视图边界的图像呢？如果你做得正确，就不需要使用draw9patch工具。可以在这里找到更多的分步教程：抱歉，在问题被编辑之前，一个领域类调用了无限循环。只要做一些小的改变，让我知道，然后我会再次投票。它总是给蓝影！
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<!-- Drop Shadow Stack -->
<item>
<shape>
<padding android:top="1dp" android:right="1dp" android:bottom="1dp" android:left="1dp" />
<solid android:color="#00CCCCCC" />
</shape>
</item>
<item>
<shape>
<padding android:top="1dp" android:right="1dp" android:bottom="1dp" android:left="1dp" />
<solid android:color="#10CCCCCC" />
</shape>
</item>
<item>
<shape>
<padding android:top="1dp" android:right="1dp" android:bottom="1dp" android:left="1dp" />
<solid android:color="#20CCCCCC" />
</shape>
</item>
<item>
<shape>
<padding android:top="1dp" android:right="1dp" android:bottom="1dp" android:left="1dp" />
<solid android:color="#30CCCCCC" />
</shape>
</item>
<item>
<shape>
<padding android:top="1dp" android:right="1dp" android:bottom="1dp" android:left="1dp" />
<solid android:color="#50CCCCCC" />
</shape>
</item>
<!-- Background -->
<item>
<shape>
<solid android:color="@color/white" />
<corners android:radius="3dp" />
</shape>
</item>
</layer-list>
public class ShadowImageView extends ImageView {
public ShadowImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public ShadowImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ShadowImageView(Context context) {
super(context);
}
private Paint createShadow() {
Paint mShadow = new Paint();
float radius = 10.0f;
float xOffset = 0.0f;
float yOffset = 2.0f;
// color=black
int color = 0xFF000000;
mShadow.setShadowLayer(radius, xOffset, yOffset, color);
return mShadow;
}
@Override
protected void onDraw(Canvas canvas) {
Paint mShadow = createShadow();
Drawable d = getDrawable();
if (d != null){
setLayerType(LAYER_TYPE_SOFTWARE, mShadow);
Bitmap bitmap = ((BitmapDrawable) getDrawable()).getBitmap();
canvas.drawBitmap(bitmap, 0.0f, 0.0f, mShadow);
} else {
super.onDraw(canvas);
}
};
}
private static final int GRAY_COLOR_FOR_SHADE = Color.argb(50, 79, 79, 79);
// this method takes a bitmap and draws around it 4 rectangles with gradient to create a
// shadow effect.
public static Bitmap addShadowToBitmap(Bitmap origBitmap) {
int shadowThickness = 13; // can be adjusted as needed
int bmpOriginalWidth = origBitmap.getWidth();
int bmpOriginalHeight = origBitmap.getHeight();
int bigW = bmpOriginalWidth + shadowThickness * 2; // getting dimensions for a bigger bitmap with margins
int bigH = bmpOriginalHeight + shadowThickness * 2;
Bitmap containerBitmap = Bitmap.createBitmap(bigW, bigH, Bitmap.Config.ARGB_8888);
Bitmap copyOfOrigBitmap = Bitmap.createScaledBitmap(origBitmap, bmpOriginalWidth, bmpOriginalHeight, false);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
Canvas canvas = new Canvas(containerBitmap); // drawing the shades on the bigger bitmap
//right shade - direction of gradient is positive x (width)
Shader rightShader = new LinearGradient(bmpOriginalWidth, 0, bigW, 0, GRAY_COLOR_FOR_SHADE,
Color.TRANSPARENT, Shader.TileMode.CLAMP);
paint.setShader(rightShader);
canvas.drawRect(bigW - shadowThickness, shadowThickness, bigW, bigH - shadowThickness, paint);
//bottom shade - direction is positive y (height)
Shader bottomShader = new LinearGradient(0, bmpOriginalHeight, 0, bigH, GRAY_COLOR_FOR_SHADE,
Color.TRANSPARENT, Shader.TileMode.CLAMP);
paint.setShader(bottomShader);
canvas.drawRect(shadowThickness, bigH - shadowThickness, bigW - shadowThickness, bigH, paint);
//left shade - direction is negative x
Shader leftShader = new LinearGradient(shadowThickness, 0, 0, 0, GRAY_COLOR_FOR_SHADE,
Color.TRANSPARENT, Shader.TileMode.CLAMP);
paint.setShader(leftShader);
canvas.drawRect(0, shadowThickness, shadowThickness, bigH - shadowThickness, paint);
//top shade - direction is negative y
Shader topShader = new LinearGradient(0, shadowThickness, 0, 0, GRAY_COLOR_FOR_SHADE,
Color.TRANSPARENT, Shader.TileMode.CLAMP);
paint.setShader(topShader);
canvas.drawRect(shadowThickness, 0, bigW - shadowThickness, shadowThickness, paint);
// starting to draw bitmap not from 0,0 to get margins for shade rectangles
canvas.drawBitmap(copyOfOrigBitmap, shadowThickness, shadowThickness, null);
return containerBitmap;
}
public class ShadowGenerator {
// Percent of actual icon size
private static final float HALF_DISTANCE = 0.5f;
public static final float BLUR_FACTOR = 0.5f/48;
// Percent of actual icon size
private static final float KEY_SHADOW_DISTANCE = 1f/48;
public static final int KEY_SHADOW_ALPHA = 61;
public static final int AMBIENT_SHADOW_ALPHA = 30;
private static final Object LOCK = new Object();
// Singleton object guarded by {@link #LOCK}
private static ShadowGenerator sShadowGenerator;
private int mIconSize;
private final Canvas mCanvas;
private final Paint mBlurPaint;
private final Paint mDrawPaint;
private final Context mContext;
private ShadowGenerator(Context context) {
mContext = context;
mIconSize = Utils.convertDpToPixel(context,63);
mCanvas = new Canvas();
mBlurPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
mBlurPaint.setMaskFilter(new BlurMaskFilter(mIconSize * BLUR_FACTOR, Blur.NORMAL));
mDrawPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
}
public synchronized Bitmap recreateIcon(Bitmap icon) {
mIconSize = Utils.convertDpToPixel(mContext,3)+icon.getWidth();
int[] offset = new int[2];
Bitmap shadow = icon.extractAlpha(mBlurPaint, offset);
Bitmap result = Bitmap.createBitmap(mIconSize, mIconSize, Config.ARGB_8888);
mCanvas.setBitmap(result);
// Draw ambient shadow
mDrawPaint.setAlpha(AMBIENT_SHADOW_ALPHA);
mCanvas.drawBitmap(shadow, offset[0], offset[1], mDrawPaint);
// Draw key shadow
mDrawPaint.setAlpha(KEY_SHADOW_ALPHA);
mCanvas.drawBitmap(shadow, offset[0], offset[1] + KEY_SHADOW_DISTANCE * mIconSize, mDrawPaint);
// Draw the icon
mDrawPaint.setAlpha(255);
mCanvas.drawBitmap(icon, 0, 0, mDrawPaint);
mCanvas.setBitmap(null);
return result;
}
public static ShadowGenerator getInstance(Context context) {
synchronized (LOCK) {
if (sShadowGenerator == null) {
sShadowGenerator = new ShadowGenerator(context);
}
}
return sShadowGenerator;
}
}