自定义View编写圆形轨迹图

最新推荐文章于 2022-04-29 10:45:48 发布

原创最新推荐文章于 2022-04-29 10:45:48 发布 · 477 阅读

0 ·

CC 4.0 BY-SA版权

本文介绍了一种使用Android自定义View实现动态圆环进度条的方法。通过代码演示了如何设置圆环的颜色、宽度及进度，并实现了随着进度变化而改变颜色的效果。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.RectF;

import android.util.AttributeSet;

import android.view.View;

public class MyView extends View {

public MyView(Context context, AttributeSet attrs) {

super(context, attrs);

// TODO Auto-generated constructor stub

paint = new Paint();

mPaint = new Paint();

}

/**

* 画笔对象的引用

private Paint paint,mPaint,paint2;

int i = 0;

/**

* 圆环的宽度

private float roundWidth = 10;

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

/**

* 画最外层的大圆环

int centre = getWidth() / 2; // 获取圆心的x坐标

int radius = (int) (centre - roundWidth / 2); // 圆环的半径

paint.setColor(Color.CYAN);

paint.setStyle(Paint.Style.FILL); // 设置空心

paint.setStrokeWidth(roundWidth); // 设置圆环的宽度

paint.setAntiAlias(true); // 消除锯齿

canvas.drawCircle(centre, centre, radius, paint); // 画出圆环

i += 1;

/**

* 画圆弧，画圆环的进度

// 设置进度是实心还是空心

paint.setStrokeWidth(roundWidth); // 设置圆环的宽度

RectF oval = new RectF(centre - radius, centre - radius, centre

+ radius, centre + radius); // 用于定义的圆弧的形状和大小的界限

int degree = 360 * i / 360;

if (degree%360 == 0) {

int x = (int) (Math.random() * 16777777);

String hex = Integer.toHexString(x);

if (hex.length() == 6) {

mPaint.setColor(Color.parseColor("#" + hex));

} else {

mPaint.setColor(Color.RED);

}

i=0;

}

canvas.drawArc(oval, 0, degree, true, mPaint);

invalidate();

}

布局如下：

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

xmlns:tools=" http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context=".MainActivity" >

<com.example.day30_shanview.MyView

android:layout_width="match_parent"

android:layout_height="match_parent"

</RelativeLayout>

Vimport android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.RectF;

import android.util.AttributeSet;

import android.view.View;

public class MyView extends View {

public MyView(Context context, AttributeSet attrs) {

super(context, attrs);

// TODO Auto-generated constructor stub

paint = new Paint();

mPaint = new Paint();

}

/**

* 画笔对象的引用

private Paint paint,mPaint,paint2;

int i = 0;

/**

* 圆环的宽度

private float roundWidth = 10;

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

/**

* 画最外层的大圆环

int centre = getWidth() / 2; // 获取圆心的x坐标

int radius = (int) (centre - roundWidth / 2); // 圆环的半径

paint.setColor(Color.CYAN);

paint.setStyle(Paint.Style.FILL); // 设置空心

paint.setStrokeWidth(roundWidth); // 设置圆环的宽度

paint.setAntiAlias(true); // 消除锯齿

canvas.drawCircle(centre, centre, radius, paint); // 画出圆环

i += 1;

/**

* 画圆弧，画圆环的进度

// 设置进度是实心还是空心

paint.setStrokeWidth(roundWidth); // 设置圆环的宽度

RectF oval = new RectF(centre - radius, centre - radius, centre

+ radius, centre + radius); // 用于定义的圆弧的形状和大小的界限

int degree = 360 * i / 360;

if (degree%360 == 0) {

int x = (int) (Math.random() * 16777777);

String hex = Integer.toHexString(x);

if (hex.length() == 6) {

mPaint.setColor(Color.parseColor("#" + hex));

} else {

mPaint.setColor(Color.RED);

}

i=0;

}

canvas.drawArc(oval, 0, degree, true, mPaint);

invalidate();

}

布局如下：

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

xmlns:tools=" http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context=".MainActivity" >

<com.example.day30_shanview.MyView

android:layout_width="match_parent"

android:layout_height="match_parent"

</RelativeLayout>