Android View加载圆形图片且同时绘制圆形图片的外部边缘边线及边框:LayerDrawable实现
LayerDrawable实现的结果和附录文章1,2,3中的layer-list一致。我写个例子,这次使用LayerDrawable把附录文章4的功能再次实现走通一遍。
写一个布局,简单放一个正方形的View:
- <?xml version="1.0" encoding="utf-8"?>
- <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:layout_width="match_parent"
- android:layout_height="match_parent"
- android:background="@android:color/darker_gray"
- android:orientation="vertical">
- <View
- android:id="@+id/view"
- android:layout_width="300dp"
- android:layout_height="300dp"
- android:layout_centerInParent="true" />
- </RelativeLayout>
然后在上层写Java代码:
- package zhangphil.app;
- import android.graphics.BitmapFactory;
- import android.graphics.Color;
- import android.graphics.Paint;
- import android.graphics.drawable.Drawable;
- import android.graphics.drawable.LayerDrawable;
- import android.graphics.drawable.ShapeDrawable;
- import android.graphics.drawable.shapes.OvalShape;
- import android.support.v4.graphics.drawable.RoundedBitmapDrawable;
- import android.support.v4.graphics.drawable.RoundedBitmapDrawableFactory;
- import android.support.v7.app.AppCompatActivity;
- import android.os.Bundle;
- import android.view.View;
- public class MainActivity extends AppCompatActivity {
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- int width = 50;
- //最外部的白色环形边框
- OvalShape ovalShape0 = new OvalShape();
- ShapeDrawable drawable0 = new ShapeDrawable(ovalShape0);
- drawable0.getPaint().setColor(Color.WHITE);
- drawable0.getPaint().setStyle(Paint.Style.FILL);
- drawable0.getPaint().setAntiAlias(true);
- drawable0.getPaint().setStrokeWidth(width);
- //黄色边框
- OvalShape ovalShape1 = new OvalShape();
- ShapeDrawable drawable1 = new ShapeDrawable(ovalShape1);
- drawable1.getPaint().setColor(Color.YELLOW);
- drawable1.getPaint().setStyle(Paint.Style.FILL);
- drawable1.getPaint().setAntiAlias(true);
- drawable1.getPaint().setStrokeWidth(width);
- //红色边框
- OvalShape ovalShape2 = new OvalShape();
- ShapeDrawable drawable2 = new ShapeDrawable(ovalShape2);
- drawable2.getPaint().setColor(Color.RED);
- drawable2.getPaint().setStyle(Paint.Style.FILL);
- drawable2.getPaint().setAntiAlias(true);
- drawable2.getPaint().setStrokeWidth(width);
- //最里面的图像
- RoundedBitmapDrawable drawable3 = RoundedBitmapDrawableFactory.create(getResources(), BitmapFactory.decodeResource(getResources(), R.drawable.zhangphil));
- drawable3.setCircular(true);
- drawable3.setAntiAlias(true);
- Drawable[] layers = new Drawable[4];
- layers[0] = drawable0;
- layers[1] = drawable1;
- layers[2] = drawable2;
- layers[3] = drawable3;
- LayerDrawable layerDrawable = new LayerDrawable(layers);
- //针对每一个图层进行填充,使得各个圆环之间相互有间隔,否则就重合成一个了。
- layerDrawable.setLayerInset(0, width, width, width, width);
- layerDrawable.setLayerInset(1, width * 2, width * 2, width * 2, width * 2);
- layerDrawable.setLayerInset(2, width * 3, width * 3, width * 3, width * 3);
- layerDrawable.setLayerInset(3, width * 4, width * 4, width * 4, width * 4);
- final View view = findViewById(R.id.view);
- view.setBackgroundDrawable(layerDrawable);
- }
- }
代码运行结果:
最里面的图像是我csdn博客的头像。
需要注意的是,我在写xml布局时候,特意写了一个正方形的View,假设这个View不是正方形,那么在上层java代码中使用OvalShape绘制图形则会因为屏幕的宽高变化成为椭圆而非圆。因此,作为一点儿经验,如果要在项目开发中制作圆形,务必保持正方形的宽高比。
附录:
1,《Android layer-list(1)》链接地址:http://blog.csdn.net/zhangphil/article/details/517209244
2,《Android layer-list:联合shape(2)》链接地址:http://blog.csdn.net/zhangphil/article/details/51721283
3,《Android layer-list(3)》链接地址:http://blog.csdn.net/zhangphil/article/details/51721816
4,《Android ImageView加载圆形图片且同时绘制圆形图片的外部边缘边线及边框》链接地址:http://blog.csdn.net/zhangphil/article/details/51944262
5,《Android ShapeDrawable之OvalShape、RectShape、PaintDrawable、ArcShape》链接地址:http://blog.csdn.net/zhangphil/article/details/52025152
6,《Android RoundedBitmapDrawable:Android官方的圆角图形图象实现方案》链接地址:http://blog.csdn.net/zhangphil/article/details/51829650