如何编程方式centerCrop图像通过保持宽高比像centerCrop做XML？ [英] How to centerCrop an image Programatically by maintaining Aspect ratio like centerCrop do in XML?

问题描述

如何centerCrop喜欢同样的方法centerCrop做Android的XML的图像？我不想裁剪图像。我的心已经尝试下面的code，但它是裁剪图像的中心部分，它产生一个方形的形象，我想同样centerCrop功能使用在android.Can任何人的帮助画布？希望我的问题是清楚的给你。

 位图位= BitmapFactory.de codeResource（RES（R.drawable.ice））;
        位图cropBmp;
        如果（bitmap.getWidth（）＆GT = bitmap.getHeight（））{            cropBmp = Bitmap.createBitmap（
                    位图，
                    bitmap.getWidth（）/ 2  -  bitmap.getHeight（）/ 2，
                    0，
                    bitmap.getHeight（），
                    bitmap.getHeight（）
            ）;        }其他{            cropBmp = Bitmap.createBitmap（
                    位图，
                    0，
                    bitmap.getHeight（）/ 2  -  bitmap.getWidth（）/ 2，
                    bitmap.getWidth（），
                    bitmap.getWidth（）
            ）;
        }        dstRectForRender.set（50,20，500，360）;
        canvas2.drawBitmap（cropBmp，空，dstRectForRender，油漆）;
 

解决方案

如果你想要做同样的效果（完全相同的效果），可以收看的Andr​​oid如何做到这一点的位置：<一href=\"https://github.com/android/platform_frameworks_base/blob/3f453164ec884d26a556477027b430cb22a9b7e3/core/java/android/widget/ImageView.java\" rel=\"nofollow\">https://github.com/android/platform_frameworks_base/blob/3f453164ec884d26a556477027b430cb22a9b7e3/core/java/android/widget/ImageView.java

code约CENTER_CROP的有趣的部分：

  [...]
mDrawMatrix = mMatrix;浮规模;
浮DX = 0，DY = 0;如果（DWIDTH * vheight＆GT; vwidth *做切片）{
    规模=（浮点）vheight /（浮点）做切片;
    DX =（vwidth  -  DWIDTH *等级）* 0.5F;
}其他{
    规模=（浮点）vwidth /（浮点）DWIDTH;
    DY =（vheight  - 做切片*等级）* 0.5F;
}mDrawMatrix.setScale（秤，秤）;
mDrawMatrix.postTranslate（（int）的（DX + 0.5F），（INT）（DY + 0.5F））;[...]
 

How to centerCrop an image like the same method "centerCrop" do in xml android ? I don't want to crop the center of the image .I have tried the below code but ,it was cropping the center portion of the image,and it produce a square shaped image,I want the same centerCrop function to use in a Canvas on android.Can anyone help?? Hope my question is clear to you.

 Bitmap bitmap=BitmapFactory.decodeResource(res, (R.drawable.ice));
        Bitmap cropBmp;
        if (bitmap.getWidth() >= bitmap.getHeight()){

            cropBmp = Bitmap.createBitmap(
                    bitmap,
                    bitmap.getWidth()/2 - bitmap.getHeight()/2,
                    0,
                    bitmap.getHeight(),
                    bitmap.getHeight()
            );

        }else{

            cropBmp = Bitmap.createBitmap(
                    bitmap,
                    0,
                    bitmap.getHeight()/2 - bitmap.getWidth()/2,
                    bitmap.getWidth(),
                    bitmap.getWidth()
            );
        }

        dstRectForRender.set(50,20 ,500 ,360 );
        canvas2.drawBitmap(cropBmp, null, dstRectForRender, paint);

解决方案

If you want to do same effect (exactly same effect), you can watch how Android do it here: https://github.com/android/platform_frameworks_base/blob/3f453164ec884d26a556477027b430cb22a9b7e3/core/java/android/widget/ImageView.java

Interesting part of code about CENTER_CROP:

[...]
mDrawMatrix = mMatrix;

float scale;
float dx = 0, dy = 0;

if (dwidth * vheight > vwidth * dheight) {
    scale = (float) vheight / (float) dheight; 
    dx = (vwidth - dwidth * scale) * 0.5f;
} else {
    scale = (float) vwidth / (float) dwidth;
    dy = (vheight - dheight * scale) * 0.5f;
}

mDrawMatrix.setScale(scale, scale);
mDrawMatrix.postTranslate((int) (dx + 0.5f), (int) (dy + 0.5f));

[...]

这篇关于如何编程方式centerCrop图像通过保持宽高比像centerCrop做XML？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！