目录介绍
01.阴影效果有哪些实现方式
阴影效果有哪些实现方式
否定上面前两种方案原因分析?
网上一些介绍阴影效果方案
阴影是否占位
02.实现阴影效果Api
思考一下如何实现View阴影效果?
paint.setShadowLayer(float radius, float dx, float dy, int shadowColor);
简单介绍一下这几个参数:
终于找到了设置颜色的,通过设置shadowColor来控制视图的阴影颜色。
03.设置阴影需要注意哪些
其中涉及到几个属性,阴影的宽度,view到Viewgroup的距离,如果视图和父布局一样大的话,那阴影就不好显示,如果要能够显示出来就必须设置clipChildren=false。
还有就是视图自带的圆角,大部分背景都是有圆角的,比如上图中的圆角,需要达到高度还原阴影的效果就是的阴影的圆角和背景保持一致。
04.常见Shape实现阴影效果
多个drawable叠加
阴影效果代码如下所示
<?xml version="1.0" encoding="utf-8"?
<layer-list xmlns:android="http://schemas.android.com/apk/res/android"
<item
<shape android:shape="rectangle"
<solid android:color="@color/indexShadowColor_1" /
<corners android:radius="5dip" /
<padding
android:bottom="1dp"
android:left="1dp"
android:right="1dp"
android:top="1dp" /
</shape
</item
<item
<shape android:shape="rectangle"
<solid android:color="@color/indexShadowColor_2" /
<corners android:radius="5dip" /
<padding
android:bottom="1dp"
android:left="1dp"
android:right="1dp"
android:top="1dp" /
</shape
</item
……
<item
<shape android:shape="rectangle"
<corners android:radius="5dip" /
<solid android:color="@color/indexColor" /
</shape
</item
</layer-list
05.自定义阴影效果控件
首先自定义属性
<declare-styleable name="ShadowLayout"
<!--阴影的圆角大小--
<attr name="yc_cornerRadius" format="dimension" /
<!--阴影的扩散范围(也可以理解为扩散程度)--
<attr name="yc_shadowLimit" format="dimension" /
<!--阴影颜色--
<attr name="yc_shadowColor" format="color" /
<!--x轴的偏移量--
<attr name="yc_dx" format="dimension" /
<!--y轴的偏移量--
<attr name="yc_dy" format="dimension" /
<!--左边是否显示阴影--
<attr name="yc_leftShow" format="boolean" /
<!--右边是否显示阴影--
<attr name="yc_rightShow" format="boolean" /
<!--上边是否显示阴影--
<attr name="yc_topShow" format="boolean" /
<!--下面是否显示阴影--
<attr name="yc_bottomShow" format="boolean" /
</declare-styleable
代码如下所示
/**
* <pre
* @author yangchong
* blog : https://github.com/yangchong211
* time : 2018/7/20
* desc : 自定义阴影
* revise:
*/
public class ShadowLayout extends FrameLayout {
/**
* 阴影颜色
*/
private int mShadowColor;
/**
* 阴影的扩散范围(也可以理解为扩散程度)
*/
private float mShadowLimit;
/**
* 阴影的圆角大小
*/
private float mCornerRadius;
/**
* x轴的偏移量
*/
private float mDx;
/**
* y轴的偏移量
*/
private float mDy;
/**
* 左边是否显示阴影
*/
private boolean leftShow;
/**
* 右边是否显示阴影
*/
private boolean rightShow;
/**
* 上边是否显示阴影
*/
private boolean topShow;
/**
* 下面是否显示阴影
*/
private boolean bottomShow;
private boolean mInvalidateShadowOnSizeChanged = true;
private boolean mForceInvalidateShadow = false;
public ShadowLayout(Context context) {
super(context);
initView(context, null);
}
public ShadowLayout(Context context, AttributeSet attrs) {
super(context, attrs);
initView(context, attrs);
}
public ShadowLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initView(context, attrs);
}
@Override
protected int getSuggestedMinimumWidth() {
return 0;
}
@Override
protected int getSuggestedMinimumHeight() {
return 0;
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
if (w 0 && h 0 && (getBackground() == null || mInvalidateShadowOnSizeChanged
|| mForceInvalidateShadow)) {
mForceInvalidateShadow = false;
setBackgroundCompat(w, h);
}
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
if (mForceInvalidateShadow) {
mForceInvalidateShadow = false;
setBackgroundCompat(right - left, bottom - top);
}
}
public void setInvalidateShadowOnSizeChanged(boolean invalidateShadowOnSizeChanged) {
mInvalidateShadowOnSizeChanged = invalidateShadowOnSizeChanged;
}
public void invalidateShadow() {
mForceInvalidateShadow = true;
requestLayout();
invalidate();
}
private void initView(Context context, AttributeSet attrs) {
initAttributes(context, attrs);
int xPadding = (int) (mShadowLimit + Math.abs(mDx));
int yPadding = (int) (mShadowLimit + Math.abs(mDy));
int left;
int right;
int top;
int bottom;
if (leftShow) {
left = xPadding;
} else {
left = 0;
}
if (topShow) {
top = yPadding;
} else {
top = 0;
}
if (rightShow) {
right = xPadding;
} else {
right = 0;
}
if (bottomShow) {
bottom = yPadding;
} else {
bottom = 0;
}
setPadding(left, top, right, bottom);
}
@SuppressWarnings("deprecation")
private void setBackgroundCompat(int w, int h) {
Bitmap bitmap = createShadowBitmap(w, h, mCornerRadius, mShadowLimit, mDx,
mDy, mShadowColor, Color.TRANSPARENT);
BitmapDrawable drawable = new BitmapDrawable(getResources(), bitmap);
if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.JELLY_BEAN) {
setBackgroundDrawable(drawable);
} else {
setBackground(drawable);
}
}
private void initAttributes(Context context, AttributeSet attrs) {
TypedArray attr = getTypedArray(context, attrs, R.styleable.ShadowLayout);
if (attr == null) {
return;
}
try {
//默认是显示
leftShow = attr.getBoolean(R.styleable.ShadowLayout_yc_leftShow, true);
rightShow = attr.getBoolean(R.styleable.ShadowLayout_yc_rightShow, true);
bottomShow = attr.getBoolean(R.styleable.ShadowLayout_yc_bottomShow, true);
topShow = attr.getBoolean(R.styleable.ShadowLayout_yc_topShow, true);
mCornerRadius = attr.getDimension(R.styleable.ShadowLayout_yc_cornerRadius, 0);
mShadowLimit = attr.getDimension(R.styleable.ShadowLayout_yc_shadowLimit, 0);
mDx = attr.getDimension(R.styleable.ShadowLayout_yc_dx, 0);
mDy = attr.getDimension(R.styleable.ShadowLayout_yc_dy, 0);
mShadowColor = attr.getColor(R.styleable.ShadowLayout_yc_shadowColor,
getResources().getColor(R.color.default_shadow_color));
} finally {
attr.recycle();
}
}
private TypedArray getTypedArray(Context context, AttributeSet attributeSet, int[] attr) {
return context.obtainStyledAttributes(attributeSet, attr, 0, 0);
}
private Bitmap createShadowBitmap(int shadowWidth, int shadowHeight, float cornerRadius,
float shadowRadius, float dx, float dy,
int shadowColor, int fillColor) {
//根据宽高创建bitmap背景
Bitmap output = Bitmap.createBitmap(shadowWidth, shadowHeight, Bitmap.Config.ARGB_8888);
//用画板canvas进行绘制
Canvas canvas = new Canvas(output);
RectF shadowRect = new RectF(shadowRadius, shadowRadius,
shadowWidth - shadowRadius, shadowHeight - shadowRadius);
if (dy 0) {
shadowRect.top += dy;
shadowRect.bottom -= dy;
} else if (dy < 0) {
shadowRect.top += Math.abs(dy);
shadowRect.bottom -= Math.abs(dy);
}
if (dx 0) {
shadowRect.left += dx;
shadowRect.right -= dx;
} else if (dx < 0) {
shadowRect.left += Math.abs(dx);
shadowRect.right -= Math.abs(dx);
}
Paint shadowPaint = new Paint();
shadowPaint.setAntiAlias(true);
shadowPaint.setColor(fillColor);
shadowPaint.setStyle(Paint.Style.FILL);
if (!isInEditMode()) {
shadowPaint.setShadowLayer(shadowRadius, dx, dy, shadowColor);
}
canvas.drawRoundRect(shadowRect, cornerRadius, cornerRadius, shadowPaint);
return output;
}
}
```
06.如何使用该阴影控件
十分简单,如下所示
<com.ns.yc.yccardviewlib.shadow.ShadowLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginTop="10dp"
app:yc_cornerRadius="18dp"
app:yc_dx="0dp"
app:yc_dy="0dp"
app:yc_shadowColor="#2a000000"
app:yc_shadowLimit="5dp"
<TextView
android:layout_width="wrap_content"
android:layout_height="36dp"
android:background="@drawable/shape_show_"
android:gravity="center"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:text="完全圆形圆角"
android:textColor="#000" /
</com.ns.yc.yccardviewlib.shadow.ShadowLayout
07.在recyclerView中使用注意点
在createShadowBitmap方法中,其实也可以看到需要创建bitmap对象。大家都知道bitmap比较容易造成内存过大,如果是给recyclerView中的item设置阴影效果,那么如何避免重复创建,这时候可以用到缓存。所以可以在上面的基础上再优化一下代码。
先创建key,主要是用于map集合的键。这里为何用对象Key作为map的键呢,这里是借鉴了glide缓存图片的思路,可以创建Key对象的时候传入bitmap名称和宽高属性,并且需要重写hashCode和equals方法。
public class Key {
private final String name;
private final int width;
private final int height;
public Key(String name, int width, int height) {
this.name = name;
this.width = width;
this.height = height;
}
public String getName() {
return name;
}
public int getWidth() {
return width;
}
public int getHeight() {
return height;
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
Key key = (Key) o;
if (width != key.width) {
return false;
}
if (height != key.height) {
return false;
}
return name != null ? name.equals(key.name) : key.name == null;
}
@Override
public int hashCode() {
int result = name != null ? name.hashCode() : 0;
result = 31 * result + width;
result = 31 * result + height;
return result;
}
}
然后存取操作如下所示
Key key = new Key("bitmap", shadowWidth, shadowHeight);
Bitmap output = cache.get(key);
if(output == null){
//根据宽高创建bitmap背景
output = Bitmap.createBitmap(shadowWidth, shadowHeight, Bitmap.Config.ARGB_8888);
cache.put(key, output);
LogUtil.v("bitmap对象-----","----直接创建对象,然后存入缓存之中---");
} else {
LogUtil.v("bitmap对象-----","----从缓存中取出对象---");
}
总结
以上就是这篇文章的全部内容了,希望本文的内容对大家的学习或者工作具有一定的参考学习价值,谢谢大家对ZaLou.Cn的支持。