安卓圆角背景遮罩。覆盖实现方式（适用于所有控件） _安卓

但使书种多，会有岁稔时。这篇文章主要讲述安卓圆角背景遮罩。覆盖实现方式（适用于所有控件）相关的知识，希望能为你提供帮助。
1.工具类直接用（已经改好）

package com.etwod.yulin.t4.unit; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.PorterDuff; import android.graphics.PorterDuffXfermode; import android.graphics.RectF; import android.support.annotation.ColorInt; import android.util.AttributeSet; import android.view.View; import com.etwod.yulin.android.R; /** * A circular cover view.Above other views to hide the conner.You can set radians by self. * Created by * 磊磊tua * 覆盖形成圆角 */ public class CircularCoverView extends View {private int leftTopRadians = 30; //leftTopRadians private int leftBottomRadians = 30; //leftBottomRadians private int rightTopRadians = 30; //rightTopRadians private int rightBottomRadians = 30; //rightBottomRadiansprivate int coverColor = 0xffeaeaea; //color of cover.public CircularCoverView(Context context) { this(context, null, 0); }public CircularCoverView(Context context, AttributeSet attrs) { this(context, attrs, 0); }public CircularCoverView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.CircularCoverView); leftTopRadians = typedArray.getDimensionPixelSize(R.styleable.CircularCoverView_left_top_radius, leftTopRadians); leftBottomRadians = typedArray.getDimensionPixelSize(R.styleable.CircularCoverView_left_bottom_radius, leftBottomRadians); rightTopRadians = typedArray.getDimensionPixelSize(R.styleable.CircularCoverView_right_top_radius, rightTopRadians); rightBottomRadians = typedArray.getDimensionPixelSize(R.styleable.CircularCoverView_right_bottom_radius, rightBottomRadians); coverColor = typedArray.getColor(R.styleable.CircularCoverView_cover_color, coverColor); }/** * set radians of cover. */ public void setRadians(int leftTopRadians, int rightTopRadians, int leftBottomRadians, int rightBottomRadians) { this.leftTopRadians = leftTopRadians; this.rightTopRadians = rightTopRadians; this.leftBottomRadians = leftBottomRadians; this.rightBottomRadians = rightBottomRadians; }/** * set color of cover. * * @param coverColor cover‘s color */ public void setCoverColor(@ColorInt int coverColor) { this.coverColor = coverColor; }/** * create a sector-bitmap as the dst. * * @param w width of bitmap * @param h height of bitmap * @return bitmap */ private Bitmap drawSector(int w, int h) { Bitmap bm = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); Canvas c = new Canvas(bm); Paint p = new Paint(Paint.ANTI_ALIAS_FLAG); p.setColor(0xFFFFCC44); //notice:cannot set transparent color here.otherwise cannot clip at final.c.drawArc(new RectF(0, 0, leftTopRadians * 2, leftTopRadians * 2), 180, 90, true, p); c.drawArc(new RectF(0, getHeight() - leftBottomRadians * 2, leftBottomRadians * 2, getHeight()), 90, 90, true, p); c.drawArc(new RectF(getWidth() - rightTopRadians * 2, 0, getWidth(), rightTopRadians * 2), 270, 90, true, p); c.drawArc(new RectF(getWidth() - rightBottomRadians * 2, getHeight() - rightBottomRadians * 2, getWidth(), getHeight()), 0, 90, true, p); return bm; }/** * create a rect-bitmap as the src. * * @param w width of bitmap * @param h height of bitmap * @return bitmap */ private Bitmap drawRect(int w, int h) { Bitmap bm = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); Canvas c = new Canvas(bm); Paint p = new Paint(Paint.ANTI_ALIAS_FLAG); p.setColor(coverColor); c.drawRect(new RectF(0, 0, leftTopRadians, leftTopRadians), p); c.drawRect(new RectF(0, getHeight() - leftBottomRadians, leftBottomRadians, getHeight()), p); c.drawRect(new RectF(getWidth() - rightTopRadians, 0, getWidth(), rightTopRadians), p); c.drawRect(new RectF(getWidth() - rightBottomRadians, getHeight() - rightBottomRadians, getWidth(), getHeight()), p); return bm; }@Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); Paint paint = new Paint(); paint.setFilterBitmap(false); paint.setStyle(Paint.Style.FILL); //create a canvas layer to show the mix-result int sc = canvas.saveLayer(0, 0, getWidth(), getHeight(), null, Canvas.MATRIX_SAVE_FLAG | Canvas.CLIP_SAVE_FLAG | Canvas.HAS_ALPHA_LAYER_SAVE_FLAG | Canvas.FULL_COLOR_LAYER_SAVE_FLAG | Canvas.CLIP_TO_LAYER_SAVE_FLAG); //draw sector-dst-bitmap at first. canvas.drawBitmap(drawSector(getWidth(), getHeight()), 0, 0, paint); //set Xfermode of paint. paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_OUT)); //then draw rect-src-bitmap canvas.drawBitmap(drawRect(getWidth(), getHeight()), 0, 0, paint); paint.setXfermode(null); //restore the canvas canvas.restoreToCount(sc); } }

2.在attrs 进行配置

< !-- 圆角遮罩--> < declare-styleable name="CircularCoverView"> < attr name="left_top_radius" format="dimension"/> < attr name="left_bottom_radius" format="dimension"/> < attr name="right_top_radius" format="dimension"/> < attr name="right_bottom_radius" format="dimension"/> < attr name="cover_color" format="color"/> < /declare-styleable>

3.控件的两种用法
【安卓圆角背景遮罩。覆盖实现方式（适用于所有控件）】< 1> 在布局文件的用法只需在布局设置就好了（注意：必须用相对布局实现）

相对布局 < com.etwod.yulin.t4.unit.CircularCoverView android:id="@+id/ccv_ads" android:layout_width="match_parent" android:layout_height="180dp" app:cover_color="@color/red" app:left_bottom_radius="9dp" app:left_top_radius="9dp" app:right_bottom_radius="9dp" app:right_top_radius="9dp" />

left_bottom_radius left_top_radius right_bottom_radius right_top_radius
分别代表左下左上右下右上
< 2> 在布局文件的用法只需在布局设置

RelativeLayout container = new RelativeLayout(this); //create other child views... CircularCoverView coverView = new CircularCoverView(this); coverView.setLayoutParams(new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT)); coverView.setCoverColor(Color.WHITE); coverView.setRadians(35, 35, 35, 35); container.addView(coverView);

非常好用不受任何限制，其他不能实现首选推荐！！！
by：磊磊tua