Go语言视频零基础入门到精通

yweii

现在我们就来看看怎么样把图片的四角都变成圆形的，为什么要这样做那，如果要是这样界面就会非常的美观，下面我们就来看看代码吧。
java代码：
public static Bitmap toRoundCorner(Bitmap bitmap, int pixels) {



Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888);

Canvas canvas = new Canvas(output);



final int color = 0xff424242;

final Paint paint = new Paint();

final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());

final RectF rectF = new RectF(rect);

final float roundPx = pixels;



paint.setAntiAlias(true);

canvas.drawARGB(0, 0, 0, 0);

paint.setColor(color);

canvas.drawRoundRect(rectF, roundPx, roundPx, paint);



paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));

canvas.drawBitmap(bitmap, rect, rect, paint);



return output;

}
复制代码  当我们需要圆角的时候，调用这个方法，第一个参数是传入需要转化成圆角的图片，第二个参数是圆角的度数，数值越大，圆角越大

       下面兴趣个例子，我有一个LinearLayout，我想把它的背景图片设置成圆角

       布局文件main.xml

java代码： <?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:id="@+id/layout"

androidrientation="vertical"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

>

</LinearLayout>
复制代码java代码： import android.app.Activity;

import android.graphics.Bitmap;

import android.graphics.Bitmap.Config;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.PorterDuff.Mode;

import android.graphics.PorterDuffXfermode;

import android.graphics.Rect;

import android.graphics.RectF;

import android.graphics.drawable.BitmapDrawable;

import android.graphics.drawable.Drawable;

import android.os.Bundle;

import android.widget.ImageView;

import android.widget.LinearLayout;



public class MyActivity extends Activity {

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);



// Drawable drawable = getResources().getDrawable(R.drawable.bg);

// BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;

// Bitmap bitmap = bitmapDrawable.getBitmap();



LinearLayout layout = (LinearLayout) findViewById(R.id.layout);

Drawable drawable = getResources().getDrawable(R.drawable.bg);

BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;

Bitmap bitmap = bitmapDrawable.getBitmap();



BitmapDrawable bbb = new BitmapDrawable(toRoundCorner(bitmap, 30));

layout.setBackgroundDrawable(bbb);

//ImageView imageView = (ImageView) findViewById(R.id.imgShow);

//imageView.setImageBitmap(MyActivity.getRoundedCornerBitmap(bitmap));

//imageView.setImageBitmap(MyActivity.toRoundCorner(bitmap, 20));

}

public static Bitmap toRoundCorner(Bitmap bitmap, int pixels) {



Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888);

Canvas canvas = new Canvas(output);



final int color = 0xff424242;

final Paint paint = new Paint();

final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());

final RectF rectF = new RectF(rect);

final float roundPx = pixels;



paint.setAntiAlias(true);

canvas.drawARGB(0, 0, 0, 0);

paint.setColor(color);

canvas.drawRoundRect(rectF, roundPx, roundPx, paint);



paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));

canvas.drawBitmap(bitmap, rect, rect, paint);



return output;

}

}
复制代码