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詳解Android如何自定義view實(shí)現(xiàn)圓形進(jìn)度條

更新時(shí)間：2022年01月20日 14:32:12 作者：吐?tīng)柡榻瑿oding

Android中實(shí)現(xiàn)進(jìn)度條有很多種方式，自定義進(jìn)度條一般是繼承progressBar或繼承view來(lái)實(shí)現(xiàn)。本文將介紹通過(guò)自定義View實(shí)現(xiàn)的圓形進(jìn)度條，感興趣的可以動(dòng)手試一試

Android中實(shí)現(xiàn)進(jìn)度條有很多種方式，自定義進(jìn)度條一般是繼承progressBar或繼承view來(lái)實(shí)現(xiàn)，本篇中講解的是第二種方式。

先上效果圖：

實(shí)現(xiàn)圓形進(jìn)度條總體來(lái)說(shuō)并不難，還是跟往常一樣繼承view，初始化畫(huà)筆，按下面的步驟一步步來(lái)就好了。對(duì)初學(xué)者來(lái)說(shuō)動(dòng)畫(huà)效果可能比較陌生，我們可以使用屬性動(dòng)畫(huà)中的valueAnimator來(lái)實(shí)現(xiàn)動(dòng)畫(huà)效果。

實(shí)現(xiàn)步驟：

1、畫(huà)出一個(gè)灰色的圓環(huán)作為背景。

2、畫(huà)出上層的圓環(huán)覆蓋下方的圓環(huán)。

3、加入動(dòng)畫(huà)效果

值得注意的是怎么設(shè)置圓環(huán)和文字的位置。

畫(huà)出矩形只需要傳入矩形對(duì)角線的坐標(biāo)即可，如果不加以處理的話畫(huà)出來(lái)的圓環(huán)的邊緣是不完整的，剛開(kāi)始接觸自定義view的同學(xué)們一定要先好好看看Android坐標(biāo)系相關(guān)內(nèi)容，不然很難理解位置參數(shù)為什么這樣設(shè)置。

完整代碼：

package com.example.floatingwindow.widget;
 
import android.animation.ValueAnimator;
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.util.TypedValue;
import android.view.View;
import android.view.animation.DecelerateInterpolator;
 
import androidx.annotation.Nullable;
 
import com.example.floatingwindow.R;
 
public class ProgressBarView extends View {
 
    private Paint mPaintBack;
    private Paint mPaint;
    private Paint mPaintText;
    private float process;
    private int strokeWidth = 15;
    private int textSize = 20;
    private long duration = 3000;
    private float startDegree = 0;
    private float endDegree = 360;
    private String text = "完成";
    private String defaultText = "0%";
 
 
    public ProgressBarView(Context context) {
        super(context);
        init();
    }
 
    public ProgressBarView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init();
    }
 
    public ProgressBarView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }
 
    private void init() {
        mPaintBack = new Paint();
        mPaintBack.setColor(getResources().getColor(R.color.gray));
        mPaintBack.setStyle(Paint.Style.STROKE);
        mPaintBack.setAntiAlias(true);
        mPaintBack.setStrokeCap(Paint.Cap.ROUND);
        mPaintBack.setStrokeWidth(strokeWidth);
 
        mPaint = new Paint();
        mPaint.setColor(getResources().getColor(R.color.purple_200));
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setAntiAlias(true);
        mPaint.setStrokeCap(Paint.Cap.ROUND);
        mPaint.setStrokeWidth(strokeWidth);
 
        mPaintText = new Paint();
        mPaintText.setAntiAlias(true);
        mPaintText.setStyle(Paint.Style.STROKE);
        mPaintText.setColor(Color.BLACK);
        mPaintBack.setStrokeCap(Paint.Cap.ROUND);
        mPaintText.setTextSize(sp2px(textSize));
    }
 
    public void setStrokeWidth(int width) {
        strokeWidth = width;
    }
 
    public void setTextSize(int textSize) {
        this.textSize = textSize;
    }
 
    public void setDuration(long duration) {
        this.duration = duration;
    }
 
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        //創(chuàng)建圓環(huán)矩形
        RectF rectF = new RectF(strokeWidth, strokeWidth, getWidth() - strokeWidth, getHeight() - strokeWidth);
        //畫(huà)出灰色進(jìn)度條作為背景
        canvas.drawArc(rectF, 0, 360, false, mPaintBack);
        //畫(huà)進(jìn)度條
        canvas.drawArc(rectF, 0, process, false, mPaint);
        //計(jì)算進(jìn)度
        int percent = (int) (process / 360 * 100);
        //設(shè)置文字在canvas中的位置
        Paint.FontMetrics fm = mPaintText.getFontMetrics();
        int mTxtWidth = (int) mPaintText.measureText(text, 0, defaultText.length());
        int mTxtHeight = (int) Math.ceil(fm.descent - fm.ascent);
        int x = getWidth() / 2 - mTxtWidth / 2;
        int y = getHeight() / 2 + mTxtHeight / 4;
        if (percent < 100) {
            canvas.drawText(percent + "%", x, y, mPaintText);
        } else {
            canvas.drawText(text, x, y, mPaintText);
        }
    }
 
    /**
     * 設(shè)置動(dòng)畫(huà)效果
     */
    public void start() {
        ValueAnimator valueAnimator = ValueAnimator.ofFloat(startDegree, endDegree);
        valueAnimator.setDuration(duration);
        valueAnimator.setInterpolator(new DecelerateInterpolator());
        valueAnimator.addUpdateListener(animation -> {
            process = (float) animation.getAnimatedValue();
            invalidate();
        });
        valueAnimator.start();
    }
 
    private int sp2px(int sp) {
        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, sp,
                getResources().getDisplayMetrics());
    }
}

最后就是動(dòng)畫(huà)效果了，使用valueanimator，傳入開(kāi)始和結(jié)束的進(jìn)度以及執(zhí)行時(shí)間。然后每次進(jìn)度發(fā)生變化時(shí)做UI刷新。

xml布局：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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=".MainActivity">
 
    <com.example.floatingwindow.widget.ProgressBarView
        android:id="@+id/progressBar"
        android:layout_width="150dp"
        android:layout_height="150dp"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent">
    </com.example.floatingwindow.widget.ProgressBarView>
 
</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity：

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
 
        progressBar.start()
 
        progressBar.setOnClickListener { progressBar.start()}
    }

以上就是詳解Android如何自定義view實(shí)現(xiàn)圓形進(jìn)度條的詳細(xì)內(nèi)容，更多關(guān)于Android圓形進(jìn)度條的資料請(qǐng)關(guān)注腳本之家其它相關(guān)文章！

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