java 布局 自定義類,Android 自定義布局控件-圓形RelativeLayout

Android 自定義布局控件-圓形RelativeLayout

轉自“姜徕”，原文連結：https://blog.csdn.net/jiang001002jay/article/details/61418338

效果圖 ：

建立自定義類：CircleRelativeLayout.java

package com.jzy.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) { //建構圓形

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) { //設定背景色

this.color = color;

setColors();

invalidate();

}

public void setAlhpa(int alhpa) { //設定透明度

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};

}

}

添加自定義屬性 values/attr.xml

布局檔案

擷取和設定控件 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);

}

}