canvasdrawBitmap方法怎么样在Android项目中使用-创新互联
这篇文章给大家介绍 canvas drawBitmap方法怎么样在Android项目中使用,内容非常详细,感兴趣的小伙伴们可以参考借鉴,希望对大家能有所帮助。

Android canvas drawBitmap方法详解及实例
之前自己在自定义view,用到canvas.drawBitmap(Bitmap, SrcRect, DesRect, Paint)的时候,对其中的第2和3个参数的含义含糊不清。看源码函数也没理解,然后看了一些其他的博客加上自己的理解,整理如下。首先,我们看一张图片,今天就要绘制这张图片。

然后将图片用红色的线条分成4个部分,如下:

我们自定义一个View,代码如下:
public class PoterDuffLoadingView extends View {
private Resources mResources;
private Paint mBitPaint;
private Bitmap mBitmap;
private int mTotalWidth, mTotalHeight;
private Bitmap girlBitmap;
private int girlBitWidth , girlBitHeight;
private Rect girlSrcRect , girlDesRect;
public PoterDuffLoadingView(Context context) {
super(context);
mResources = getResources();
initBitmap();
}
private void initBitmap() {
//美女图片的宽和高
girlBitmap = ((BitmapDrawable)mResources.getDrawable(R.drawable.a1)).getBitmap();
girlBitWidth = girlBitmap.getWidth();
girlBitHeight = girlBitmap.getHeight();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(girlBitmap, girlSrcRect, girlDesRect, null);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
Log.d("xxxxxx", "onSizeChanged , w = "+w+" , h = "+h+" , mBitWidth = "+mBitWidth+" , mBitHeight = "+mBitHeight);
super.onSizeChanged(w, h, oldw, oldh);
mTotalWidth = w;
mTotalHeight = h;
girlSrcRect = new Rect(0, 0, girlBitWidth, girlBitHeight);
girlDesRect = new Rect(0, 0, girlBitWidth, girlBitHeight);
}
} 本文名称:canvasdrawBitmap方法怎么样在Android项目中使用-创新互联
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