標籤:ant create idt ret nal 擷取 logs 布局 skin
android中的ImageView只能顯示矩形的圖片,這樣一來不能滿足我們其他的需求,比如要顯示圓角矩形的圖片,這個時候,我們就需要自訂ImageView了,其原理就是首先擷取到圖片的Bitmap,然後進行裁剪對應的圓角矩形的bitmap,然後在onDraw()進行繪製圓角矩形圖片輸出。
如下:
自訂的圓形的ImageView類的實現代碼如下:
package com.xc.xcskin.view;import android.content.Context;import android.graphics.Bitmap;import android.graphics.Bitmap.Config;import android.graphics.Canvas;import android.graphics.Paint;import android.graphics.RectF;import android.graphics.PorterDuff.Mode;import android.graphics.PorterDuffXfermode;import android.graphics.Rect;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.Drawable;import android.util.AttributeSet;import android.widget.ImageView;/** * 自訂的圓角矩形ImageView,可以直接當組件在布局中使用。 * @author caizhiming * */public class XCRoundRectImageView extends ImageView{ private Paint paint; public XCRoundRectImageView(Context context) { this(context,null); } public XCRoundRectImageView(Context context, AttributeSet attrs) { this(context, attrs,0); } public XCRoundRectImageView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); paint = new Paint(); } /** * 繪製圓角矩形圖片 * @author caizhiming */ @Override protected void onDraw(Canvas canvas) { Drawable drawable = getDrawable(); if (null != drawable) { Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap(); Bitmap b = getRoundBitmap(bitmap, 20); final Rect rectSrc = new Rect(0, 0, b.getWidth(), b.getHeight()); final Rect rectDest = new Rect(0,0,getWidth(),getHeight()); paint.reset(); canvas.drawBitmap(b, rectSrc, rectDest, paint); } else { super.onDraw(canvas); } } /** * 擷取圓角矩形圖片方法 * @param bitmap * @param roundPx,一般設定成14 * @return Bitmap * @author caizhiming */ private Bitmap getRoundBitmap(Bitmap bitmap, int roundPx) { Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888); Canvas canvas = new Canvas(output); final int color = 0xff424242; final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); final RectF rectF = new RectF(rect); paint.setAntiAlias(true); canvas.drawARGB(0, 0, 0, 0); paint.setColor(color); int x = bitmap.getWidth(); canvas.drawRoundRect(rectF, roundPx, roundPx, paint); paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN)); canvas.drawBitmap(bitmap, rect, rect, paint); return output; } }
完成這個自訂類後,就可以使用這個類了,就是把這個當組件在布局中使用即可,比如:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" > <com.xc.xcskin.view.XCRoundRectImageView android:id="@+id/roundRectImageView" android:layout_centerInParent="true" android:layout_width="200dp" android:layout_height="200dp" android:src="@drawable/roundimageview" /></RelativeLayout>
Android開發之自訂圓角矩形圖片ImageView的實現