Android实现圆角
Android 实现圆角
View 使用 ViewOutlineProvider 裁剪 制作圆角或者倒角 (API21 及以上)
view.setOutlineProvider(new ViewOutlineProvider() {
@Override
public void getOutline(View view, Outline outline) {
//设置圆角；
outline.setRoundRect(0,0,view.getWidth(),view.getHeight(),20);
}
});
//setClipToOutline方法针对于前景进行裁剪，如果设置为false则表示禁止裁剪，setOutlineProvider方法将无效。
//注意：如果我们的应用设置了android:hardwareAccelerated="false"，以上方式都将无效
view.setClipToOutline(true);
kotlin 扩展方法：
/**
* 设置View圆角
*/
fun View.setCornerAfterLollipop(radius: Int) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP && radius > 0) {
this.outlineProvider = object : ViewOutlineProvider() {
override fun getOutline(view: View, outline: Outline) {
val rect = Rect()
view.getDrawingRect(rect)
val leftMargin = 0
val topMargin = 0
val selfRect = Rect(
leftMargin,
topMargin,
rect.right - rect.left - leftMargin,
rect.bottom - rect.top - topMargin
)
outline.setRoundRect(selfRect, radius.toFloat())
}
}
this.clipToOutline = true
}
}
CardView 实现圆角和圆形
<android.support.v7.widget.CardView
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_gravity="center"
android:layout_marginTop="10dp"
app:cardCornerRadius="50dp">
<ImageView
android:layout_width="100dp"
android:layout_height="100dp"
android:scaleType="centerCrop"
android:src="@drawable/girl" />
</android.support.v7.widget.CardView>
设置 CardView 的 cardCornerRadius 属性，如果要展示指定的圆角，把这个值设置成你想要的圆角值就行，如果展示为圆形，首先要设置 CardView 长宽等值，而且 cardCornerRadius 为长宽的一半
BitmapShader
BitmapShader 圆角边框
/**
* 通过BitmapShader 圆角边框
*/
public static Bitmap getRoundBitmapByShader(Bitmap bitmap, int outWidth, int outHeight, int radius, int boarder) {
if (bitmap == null) {
return null;
}
int width = bitmap.getWidth();
int height = bitmap.getHeight();
float widthScale = outWidth * 1f / width;
float heightScale = outHeight * 1f / height;
Matrix matrix = new Matrix();
matrix.setScale(widthScale, heightScale);
//创建输出的bitmap
Bitmap desBitmap = Bitmap.createBitmap(outWidth, outHeight, Bitmap.Config.ARGB_8888);
//创建canvas并传入desBitmap，这样绘制的内容都会在desBitmap上
Canvas canvas = new Canvas(desBitmap);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
//创建着色器
BitmapShader bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
//给着色器配置matrix
bitmapShader.setLocalMatrix(matrix);
paint.setShader(bitmapShader);
//创建矩形区域并且预留出border
RectF rect = new RectF(boarder, boarder, outWidth - boarder, outHeight - boarder);
//把传入的bitmap绘制到圆角矩形区域内
canvas.drawRoundRect(rect, radius, radius, paint);
if (boarder > 0) {
//绘制boarder
Paint boarderPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
boarderPaint.setColor(Color.GREEN);
boarderPaint.setStyle(Paint.Style.STROKE);
boarderPaint.setStrokeWidth(boarder);
canvas.drawRoundRect(rect, radius, radius, boarderPaint);
}
return desBitmap;
}