今天就跟大家聊聊有关怎么在Android中利用ImageView控件实现一个圆角功能,可能很多人都不太了解,为了让大家更加了解,小编给大家总结了以下内容,希望大家根据这篇文章可以有所收获。创建CustomImageView 类在你的项目中(
今天就跟大家聊聊有关怎么在Android中利用ImageView控件实现一个圆角功能,可能很多人都不太了解,为了让大家更加了解,小编给大家总结了以下内容,希望大家根据这篇文章可以有所收获。
创建CustomImageView 类在你的项目中(源码如下)
import android.content.Context;import android.content.res.TypedArray;import android.graphics.Bitmap;import android.graphics.Bitmap.Config;import android.graphics.BitmapFactory;import android.graphics.canvas;import android.graphics.Matrix;import android.graphics.Paint;import android.graphics.PorterDuff;import android.graphics.PorterDuffXfermode;import android.graphics.RectF;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.Drawable;import android.util.AttributeSet;import android.widget.ImageView;import com.towatt.charge.towatt.R;public class CustomImageView extends android.support.v7.widget.AppCompatImageView { private Paint paint; private Paint paintBorder; private Bitmap mSrcBitmap; private float mRadius; private boolean mIsCircle; public CustomImageView(final Context context) { this(context, null); } public CustomImageView(Context context, AttributeSet attrs) { this(context, attrs, R.attr.customImageViewStyle); } public CustomImageView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.CustomImageView, defStyle, 0); mRadius = ta.getDimension(R.styleable.CustomImageView_radius, 0); mIsCircle = ta.getBoolean(R.styleable.CustomImageView_circle, false); int srcResource = attrs.getAttributeResourceValue( "Http://schemas.android.com/apk/res/android", "src", 0); if (srcResource != 0) mSrcBitmap = BitmapFactory.decodeResource(getResources(), srcResource); ta.recycle(); paint = new Paint(); paint.setAntiAlias(true); paintBorder = new Paint(); paintBorder.setAntiAlias(true); } @Override public void onDraw(Canvas canvas) { int width = canvas.getWidth() - getPaddingLeft() - getPaddingRight(); int height = canvas.getHeight() - getPaddingTop() - getPaddingBottom(); Bitmap image = drawableToBitmap(getDrawable()); if (mIsCircle) { Bitmap reSizeImage = reSizeImageC(image, width, height); canvas.drawBitmap(createCircleImage(reSizeImage, width, height), getPaddingLeft(), getPaddingTop(), null); } else { Bitmap reSizeImage = reSizeImage(image, width, height); canvas.drawBitmap(createRoundImage(reSizeImage, width, height), getPaddingLeft(), getPaddingTop(), null); } } private Bitmap createRoundImage(Bitmap source, int width, int height) { Paint paint = new Paint(); paint.setAntiAlias(true); Bitmap target = Bitmap.createBitmap(width, height, Config.ARGB_8888); Canvas canvas = new Canvas(target); RectF rect = new RectF(0, 0, width, height); canvas.drawRoundRect(rect, mRadius, mRadius, paint); // 核心代码取两个图片的交集部分 paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN)); canvas.drawBitmap(source, 0, 0, paint); return target; } private Bitmap createCircleImage(Bitmap source, int width, int height) { Paint paint = new Paint(); paint.setAntiAlias(true); Bitmap target = Bitmap.createBitmap(width, height, Config.ARGB_8888); Canvas canvas = new Canvas(target); canvas.drawCircle(width / 2, height / 2, Math.min(width, height) / 2, paint); // 核心代码取两个图片的交集部分 paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN)); canvas.drawBitmap(source, (width - source.getWidth()) / 2, (height - source.getHeight()) / 2, paint); return target; } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { int width = MeasureSpec.getSize(widthMeasureSpec); int height = MeasureSpec.getSize(heightMeasureSpec); setMeasuredDimension(width, height); } private Bitmap drawableToBitmap(Drawable drawable) { if (drawable == null) { if (mSrcBitmap != null) { return mSrcBitmap; } else { return null; } } else if (drawable instanceof BitmapDrawable) { return ((BitmapDrawable) drawable).getBitmap(); } Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(bitmap); drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight()); drawable.draw(canvas); return bitmap; } private Bitmap reSizeImage(Bitmap bitmap, int newWidth, int newHeight) { int width = bitmap.getWidth(); int height = bitmap.getHeight(); // 计算出缩放比 float scaleWidth = ((float) newWidth) / width; float scaleHeight = ((float) newHeight) / height; // 矩阵缩放bitmap Matrix matrix = new Matrix(); matrix.postScale(scaleWidth, scaleHeight); return Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true); } private Bitmap reSizeImageC(Bitmap bitmap, int newWidth, int newHeight) { int width = bitmap.getWidth(); int height = bitmap.getHeight(); int x = (newWidth - width) / 2; int y = (newHeight - height) / 2; if (x > 0 && y > 0) { return Bitmap.createBitmap(bitmap, 0, 0, width, height, null, true); } float scale = 1; if (width > height) { // 按照宽度进行等比缩放 scale = ((float) newWidth) / width; } else { // 按照高度进行等比缩放 // 计算出缩放比 scale = ((float) newHeight) / height; } Matrix matrix = new Matrix(); matrix.postScale(scale, scale); return Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true); }}
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