Java 如何为 ImageView 裁剪位图？
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How can I crop a bitmap for ImageView?
提问by user2234594
I know this should be simple , but android:scaleType="centerCrop"doesn't crop Image
我知道这应该很简单，但android:scaleType="centerCrop"不会裁剪图像
I got image 1950 pixelswide and need it to be cropped by parent's width. But android:scaleType="centerCrop"doesn't crop Image. What do I need to do in layout to show only first 400 pixels, for instance or whatever screen/parent width is
我得到了1950 像素宽的图像，需要按父级的宽度裁剪它。但android:scaleType="centerCrop"不裁剪图像。我需要在布局中做什么才能只显示前400 个像素，例如或任何屏幕/父宽度
Sorry for simple question - tried to Google it - only complicated questions there. And I'm new, so don't downvote please)
对不起，简单的问题 - 尝试谷歌 - 只有复杂的问题。而且我是新手，所以请不要投票）
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/rl1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/background_color">
<ImageView
android:id="@+id/ver_bottompanelprayer"
android:layout_width="match_parent"
android:layout_height="227px"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:scaleType="matrix"
android:background="@drawable/ver_bottom_panel_tiled_long" />
</RelativeLayout>
if there's only way is to programmaticaly crop it - please give me an advice with a method
如果唯一的方法是以编程方式裁剪它 - 请给我一个方法的建议
采纳答案by g00dy
Alright, I will paste the comment as answer :) ->
好的，我会将评论粘贴为答案:) ->
RelativeLayout rl = (RelativeLayout) findViewById(R.id.rl1);
final Options bitmapOptions=new Options();
DisplayMetrics metrics = getResources().getDisplayMetrics();
bitmapOptions.inDensity = metrics.densityDpi;
bitmapOptions.inTargetDensity=1;
/*`final` modifier might be necessary for the Bitmap*/
Bitmap bmp= BitmapFactory.decodeResource(getResources(), R.drawable.ver_bottom_panel_tiled_long, bitmapOptions);
bmp.setDensity(Bitmap.DENSITY_NONE);
bmp = Bitmap.createBitmap(bmp, 0, 0, rl.getWidth(), bmp.getHeight());
Then in the code:
然后在代码中：
ImageView iv = (ImageView)v.findViewById(R.id.ver_bottompanelprayer);
if (iv != null){
iv.setImageBitmap(bmp);
}
Cheers :)
干杯:)
回答by Onur A.
Make it android:scaleType="fitStart"and for android:layout_height="400px"
制作它android:scaleType="fitStart"并为android:layout_height="400px"
回答by Niranj Patel
You can also crop image by programmatically using createBitmap.
您还可以使用createBitmap以编程方式裁剪图像。
Bitmap bm = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
bm = Bitmap.createBitmap(bm, 0, 0, 400, 400);
your_imageview.setImageBitmap(bm);
Here 400 is your width & height you can change as per your requirement.
这里 400 是您的宽度和高度，您可以根据您的要求进行更改。
回答by Phil
You can do this programmatically (this ensures you get the right height/width):
您可以以编程方式执行此操作（这可确保您获得正确的高度/宽度）：
ImageView image = (ImageView) findVieById(R.id.ver_bottompanelprayer);
DisplayMetrics dm = getResources().getDisplayMetrics();
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(1950, dm.heightPixels);
params.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
params.addRule(RelativeLayout.ALIGN_PARENT_TOP);
image.setLayoutParams(params);
image.setScaleType(ScaleType.FIT_XY);
