一、创建自定义类
package com.test.circularlayout;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.widget.RelativeLayout;
public class CircleRelativeLayout extends RelativeLayout {
private int color;
private int[] colors;
private int alpha;
public CircleRelativeLayout(Context context) {
super(context);
}
public CircleRelativeLayout(Context context, AttributeSet attrs) {
super(context,attrs);
init(context,attrs);
setWillNotDraw(false);
}
private void init(Context context, AttributeSet attrs) {
TypedArray array = context.obtainStyledAttributes(attrs,
R.styleable.CircleRelativeLayoutLayout);
color = array.getColor(R.styleable.CircleRelativeLayoutLayout_background_color,0X0000000);
alpha = array.getInteger(R.styleable.CircleRelativeLayoutLayout_background_alpha,100);
setColors();
array.recycle();
}
@Override
protected void onDraw(Canvas canvas) { //构建圆形
int width = getMeasuredWidth();
Paint mPaint = new Paint();
mPaint.setARGB(alpha,colors[0],colors[1],colors[2]);
mPaint.setAntiAlias(true);
float cirX = width / 2;
float cirY = width / 2;
float radius = width / 2;
canvas.drawCircle(cirX, cirY, radius, mPaint);
super.onDraw(canvas);
}
public void setColor(int color) { //设置背景色
this.color = color;
setColors();
invalidate();
}
public void setAlhpa(int alhpa) { //设置透明度
this.alpha = alhpa;
invalidate();
}
public void setColors() {
int red = (color & 0xff0000) >> 16;
int green = (color & 0x00ff00) >> 8;
int blue = (color & 0x0000ff);
this.colors = new int[]{red,green,blue};
}
}
二、添加自定义属性 values/attr.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="CircleRelativeLayoutLayout">
<attr name="background_color" format="color" />
<attr name="background_alpha" format="integer" />
</declare-styleable>
</resources>
三、布局文件引用
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:circle="http://schemas.android.com/apk/res-auto"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.test.circularlayout.MainActivity">
<com.test.circularlayout.CircleRelativeLayout
android:layout_margin="5dp"
android:layout_width="100dp"
android:layout_height="100dp">
<TextView
android:textColor="#ffffff"
android:text="默认的颜色"
android:layout_centerInParent="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</com.test.circularlayout.CircleRelativeLayout>
<com.test.circularlayout.CircleRelativeLayout
circle:background_color="#3838e4"
circle:background_alpha="100"
android:layout_marginLeft="110dp"
android:layout_marginTop="5dp"
android:layout_width="90dp"
android:layout_height="90dp">
<TextView
android:textColor="#ffffff"
android:text="自定义"
android:layout_centerInParent="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</com.test.circularlayout.CircleRelativeLayout>
<com.test.circularlayout.CircleRelativeLayout
android:id="@+id/crlayout"
android:layout_marginLeft="210dp"
android:layout_marginTop="5dp"
android:layout_width="80dp"
android:layout_height="80dp">
<TextView
android:textColor="#ffffff"
android:text="代码设置"
android:layout_centerInParent="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</com.test.circularlayout.CircleRelativeLayout>
</RelativeLayout>
四、获取和设置控件
public class MainActivity extends Activity {
CircleRelativeLayout crlayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
crlayout = (CircleRelativeLayout) findViewById(R.id.crlayout);
crlayout.setColor(getResources().getColor(R.color.colorAccent));
crlayout.setAlhpa(160);
}
}
