Android自定义View倒计时圆

本文实例为大家分享了Android自定义View倒计时圆的具体代码，供大家参考，具体内容如下

创建attr

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="CountDownView">
 <!--颜色-->
 <attr name="ringColor" format="color" />
 <!-- 进度文本的字体大小 -->
 <attr name="progressTextSize" format="dimension" />
 <!-- 圆环宽度 -->
 <attr name="ringWidth" format="float" />
 <!--进度文本颜色-->
 <attr name="progressTextColor" format="color"/>
 <!--倒计时-->
 <attr name="countdownTime" format="integer"/>
</declare-styleable>
</resources>

创建DisplayUtil 类

import android.content.Context;

/**
* Created by 王 on 2017/10/21.
*/

public class DisplayUtil {
/**
 * 将px装换成dp，保证尺寸不变
 * @param context
 * @param pxValue
 * @return
 */
public static int px2dp(Context context, float pxValue){
 float density = context.getResources().getDisplayMetrics().density;//得到设备的密度
 return (int) (pxValue/density+0.5f);
}
public static int dp2px(Context context,float dpValue){
 float density = context.getResources().getDisplayMetrics().density;
 return (int) (dpValue*density+0.5f);
}
public static int px2sp(Context context,float pxValue){
 float scaleDensity = context.getResources().getDisplayMetrics().scaledDensity;//缩放密度
 return (int) (pxValue/scaleDensity+0.5f);
}
public static int sp2px(Context context,float spValue) {
 float scaleDensity = context.getResources().getDisplayMetrics().scaledDensity;
 return (int) (spValue*scaleDensity+0.5f);
}
}

继承View

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ValueAnimator;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.LinearInterpolator;

/**
* Created by 王 on 2017/10/21.
*/

public class CountDownView extends View{
//圆轮颜色
private int mRingColor;
//圆轮宽度
private float mRingWidth;
//圆轮进度值文本大小
private int mRingProgessTextSize;
//宽度
private int mWidth;
//高度
private int mHeight;
private Paint mPaint;
//圆环的矩形区域
private RectF mRectF;
//
private int mProgessTextColor;
private int mCountdownTime;
private float mCurrentProgress;
private OnCountDownFinishListener mListener;

public CountDownView(Context context) {
 this(context, null);
}

public CountDownView(Context context, AttributeSet attrs) {
 this(context, attrs, 0);
}

public CountDownView(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);
 TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CountDownView);
 mRingColor = a.getColor(R.styleable.CountDownView_ringColor, context.getResources().getColor(R.color.colorAccent));
 mRingWidth = a.getFloat(R.styleable.CountDownView_ringWidth, 40);
 mRingProgessTextSize = a.getDimensionPixelSize(R.styleable.CountDownView_progressTextSize, DisplayUtil.sp2px(context, 20));
 mProgessTextColor = a.getColor(R.styleable.CountDownView_progressTextColor, context.getResources().getColor(R.color.colorAccent));
 mCountdownTime = a.getInteger(R.styleable.CountDownView_countdownTime, 10);
 a.recycle();
 mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
 mPaint.setAntiAlias(true);
 this.setWillNotDraw(false);
}

public void setCountdownTime(int mCountdownTime) {
 this.mCountdownTime = mCountdownTime;
}

@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
 super.onLayout(changed, left, top, right, bottom);
 mWidth = getMeasuredWidth();
 mHeight = getMeasuredHeight();
 mRectF = new RectF(0 + mRingWidth / 2, 0 + mRingWidth / 2,
   mWidth - mRingWidth / 2, mHeight - mRingWidth / 2);
}

@Override
protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 /**
  *圆环
  */
 //颜色
 mPaint.setColor(mRingColor);
 //空心
 mPaint.setStyle(Paint.Style.STROKE);
 //宽度
 mPaint.setStrokeWidth(mRingWidth);
 canvas.drawArc(mRectF, -90, mCurrentProgress - 360, false, mPaint);
 //绘制文本
 Paint textPaint = new Paint();
 textPaint.setAntiAlias(true);
 textPaint.setTextAlign(Paint.Align.CENTER);
 String text = mCountdownTime - (int) (mCurrentProgress / 360f * mCountdownTime) + "";
 textPaint.setTextSize(mRingProgessTextSize);
 textPaint.setColor(mProgessTextColor);

//文字居中显示
 Paint.FontMetricsInt fontMetrics = textPaint.getFontMetricsInt();
 int baseline = (int) ((mRectF.bottom + mRectF.top - fontMetrics.bottom - fontMetrics.top) / 2);
 canvas.drawText(text, mRectF.centerX(), baseline, textPaint);
}

private ValueAnimator getValA(long countdownTime) {
 ValueAnimator valueAnimator = ValueAnimator.ofFloat(0, 100);
 valueAnimator.setDuration(countdownTime);
 valueAnimator.setInterpolator(new LinearInterpolator());
 valueAnimator.setRepeatCount(0);
 return valueAnimator;
}
/**
 * 开始倒计时
 */
public void startCountDown() {
 setClickable(false);
 ValueAnimator valueAnimator = getValA(mCountdownTime * 1000);
 valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
  @Override
  public void onAnimationUpdate(ValueAnimator animation) {
   float i = Float.valueOf(String.valueOf(animation.getAnimatedValue()));
   mCurrentProgress = (int) (360 * (i / 100f));
   invalidate();
  }
 });
 valueAnimator.start();
 valueAnimator.addListener(new AnimatorListenerAdapter() {
  @Override
  public void onAnimationEnd(Animator animation) {
   super.onAnimationEnd(animation);
   //倒计时结束回调
   if (mListener != null) {
    mListener.countDownFinished();
   }
   setClickable(true);
  }

});
}
public void setAddCountDownListener(OnCountDownFinishListener mListener) {
 this.mListener = mListener;
}
public interface OnCountDownFinishListener {
 void countDownFinished();
}

}

布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.circulardemo.MainActivity">

<com.example.circulardemo.CountDownView
 android:id="@+id/cdv"
 android:layout_width="50dp"
 android:layout_height="50dp"
 android:layout_centerVertical="true"
 android:layout_centerHorizontal="true" />

</RelativeLayout>

Mainactivity

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 CountDownView countDownView = (CountDownView) findViewById(R.id.cdv);
 //启动
 countDownView.startCountDown();

countDownView.setAddCountDownListener(new CountDownView.OnCountDownFinishListener() {
  @Override
  public void countDownFinished() {
   Toast.makeText(MainActivity.this, "倒计时结束", Toast.LENGTH_SHORT).show();
  }
 });
}

}

来源：http://blog.csdn.net/qq_38259132/article/details/78492663