我正在寻找一种在 Android 中实现“状态”进度条的流畅方法，如下面的三个示例所示。 由于我不喜欢重新发明轮子，所以我想问问是否有一些我不知道的可用库。

我查了一下，找不到任何库，所以我想我需要自己实现它。这样做最简单的解决方案是什么？我应该扩展 ProgressBar 还是应该从头开始？您有任何我可以借鉴的建议或教程吗？

最佳答案

更新

请参阅this sample project ，还附上 GIF 以提供概述。

您可以根据您的要求自定义以下内容。

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.os.Bundle;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.view.View;

public class NumberProgressBar extends View {

    private Context mContext;

    /**
     * The max progress, default is 100
     */
    private int mMax = 100;

    /**
     * current progress, can not exceed the max progress.
     */
    private int mProgress = 0;

    /**
     * the progress area bar color
     */
    private int mReachedBarColor;

    /**
     * the bar unreached area color.
     */
    private int mUnreachedBarColor;

    /**
     * the progress text color.
     */
    private int mTextColor;

    /**
     * the progress text size
     */
    private float mTextSize;

    /**
     * the height of the reached area
     */
    private float mReachedBarHeight;

    /**
     * the height of the unreached area
     */
    private float mUnreachedBarHeight;

    /**
     * the suffix of the number.
     */
    private String mSuffix = "%";

    /**
     * the prefix.
     */
    private String mPrefix = "";


    private final int default_text_color = Color.rgb(66, 145, 241);
    private final int default_reached_color = Color.rgb(66,145,241);
    private final int default_unreached_color = Color.rgb(204, 204, 204);
    private final float default_progress_text_offset;
    private final float default_text_size;
    private final float default_reached_bar_height;
    private final float default_unreached_bar_height;

    /**
     * for save and restore instance of progressbar.
     */
    private static final String INSTANCE_STATE = "saved_instance";
    private static final String INSTANCE_TEXT_COLOR = "text_color";
    private static final String INSTANCE_TEXT_SIZE = "text_size";
    private static final String INSTANCE_REACHED_BAR_HEIGHT = "reached_bar_height";
    private static final String INSTANCE_REACHED_BAR_COLOR = "reached_bar_color";
    private static final String INSTANCE_UNREACHED_BAR_HEIGHT = "unreached_bar_height";
    private static final String INSTANCE_UNREACHED_BAR_COLOR = "unreached_bar_color";
    private static final String INSTANCE_MAX = "max";
    private static final String INSTANCE_PROGRESS = "progress";
    private static final String INSTANCE_SUFFIX = "suffix";
    private static final String INSTANCE_PREFIX = "prefix";
    private static final String INSTANCE_TEXT_VISBILITY = "text_visibility";

    private static final int PROGRESS_TEXT_VISIBLE = 0;
    private static final int PROGRESS_TEXT_INVISIBLE = 1;



    /**
     * the width of the text that to be drawn
     */
    private float mDrawTextWidth;

    /**
     * the drawn text start
     */
    private float mDrawTextStart;

    /**
     *the drawn text end
     */
    private float mDrawTextEnd;

    /**
     * the text that to be drawn in onDraw()
     */
    private String mCurrentDrawText;

    /**
     * the Paint of the reached area.
     */
    private Paint mReachedBarPaint;
    /**
     * the Painter of the unreached area.
     */
    private Paint mUnreachedBarPaint;
    /**
     * the Painter of the progress text.
     */
    private Paint mTextPaint;

    /**
     * Unreached Bar area to draw rect.
     */
    private RectF mUnreachedRectF = new RectF(0,0,0,0);
    /**
     * reached bar area rect.
     */
    private RectF mReachedRectF = new RectF(0,0,0,0);

    /**
     * the progress text offset.
     */
    private float mOffset;

    /**
     * determine if need to draw unreached area
     */
    private boolean mDrawUnreachedBar = true;

    private boolean mDrawReachedBar = true;

    private boolean mIfDrawText = true;

    public enum ProgressTextVisibility{
        Visible,Invisible
    };



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

    public NumberProgressBar(Context context, AttributeSet attrs) {
        this(context, attrs, R.attr.numberProgressBarStyle);
    }

    public NumberProgressBar(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        mContext = context;

        default_reached_bar_height = dp2px(1.5f);
        default_unreached_bar_height = dp2px(1.0f);
        default_text_size = sp2px(10);
        default_progress_text_offset = dp2px(3.0f);

        //load styled attributes.
        final TypedArray attributes = context.getTheme().obtainStyledAttributes(attrs, R.styleable.NumberProgressBar,
                defStyleAttr, 0);

        mReachedBarColor = attributes.getColor(R.styleable.NumberProgressBar_progress_reached_color, default_reached_color);
        mUnreachedBarColor = attributes.getColor(R.styleable.NumberProgressBar_progress_unreached_color,default_unreached_color);
        mTextColor = attributes.getColor(R.styleable.NumberProgressBar_progress_text_color,default_text_color);
        mTextSize = attributes.getDimension(R.styleable.NumberProgressBar_progress_text_size, default_text_size);

        mReachedBarHeight = attributes.getDimension(R.styleable.NumberProgressBar_progress_reached_bar_height,default_reached_bar_height);
        mUnreachedBarHeight = attributes.getDimension(R.styleable.NumberProgressBar_progress_unreached_bar_height,default_unreached_bar_height);
        mOffset = attributes.getDimension(R.styleable.NumberProgressBar_progress_text_offset,default_progress_text_offset);

        int textVisible = attributes.getInt(R.styleable.NumberProgressBar_progress_text_visibility,PROGRESS_TEXT_VISIBLE);
        if(textVisible != PROGRESS_TEXT_VISIBLE){
            mIfDrawText = false;
        }

        setProgress(attributes.getInt(R.styleable.NumberProgressBar_progress,0));
        setMax(attributes.getInt(R.styleable.NumberProgressBar_max, 100));
        //
        attributes.recycle();

        initializePainters();

    }

    @Override
    protected int getSuggestedMinimumWidth() {
        return (int)mTextSize;
    }

    @Override
    protected int getSuggestedMinimumHeight() {
        return Math.max((int)mTextSize,Math.max((int)mReachedBarHeight,(int)mUnreachedBarHeight));
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        setMeasuredDimension(measure(widthMeasureSpec,true), measure(heightMeasureSpec,false));
    }

    private int measure(int measureSpec,boolean isWidth){
        int result;
        int mode = MeasureSpec.getMode(measureSpec);
        int size = MeasureSpec.getSize(measureSpec);
        int padding = isWidth?getPaddingLeft()+getPaddingRight():getPaddingTop()+getPaddingBottom();
        if(mode == MeasureSpec.EXACTLY){
            result = size;
        }else{
            result = isWidth ? getSuggestedMinimumWidth() : getSuggestedMinimumHeight();
            result += padding;
            if(mode == MeasureSpec.AT_MOST){
                if(isWidth) {
                    result = Math.max(result, size);
                }
                else{
                    result = Math.min(result, size);
                }
            }
        }
        return result;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        if(mIfDrawText){
            calculateDrawRectF();
        }else{
            calculateDrawRectFWithoutProgressText();
        }

        if(mDrawReachedBar){
            canvas.drawRect(mReachedRectF,mReachedBarPaint);
        }

        if(mDrawUnreachedBar) {
            canvas.drawRect(mUnreachedRectF, mUnreachedBarPaint);
        }

        if(mIfDrawText)
            canvas.drawText(mCurrentDrawText,mDrawTextStart,mDrawTextEnd,mTextPaint);
    }

    private void initializePainters(){
        mReachedBarPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mReachedBarPaint.setColor(mReachedBarColor);

        mUnreachedBarPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mUnreachedBarPaint.setColor(mUnreachedBarColor);

        mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mTextPaint.setColor(mTextColor);
        mTextPaint.setTextSize(mTextSize);
    }


    private void calculateDrawRectFWithoutProgressText(){
        mReachedRectF.left = getPaddingLeft();
        mReachedRectF.top = getHeight()/2.0f - mReachedBarHeight / 2.0f;
        mReachedRectF.right = (getWidth() - getPaddingLeft() - getPaddingRight() )/(getMax()*1.0f) * getProgress() + getPaddingLeft();
        mReachedRectF.bottom = getHeight()/2.0f + mReachedBarHeight / 2.0f;

        mUnreachedRectF.left = mReachedRectF.right;
        mUnreachedRectF.right = getWidth() - getPaddingRight();
        mUnreachedRectF.top = getHeight()/2.0f +  - mUnreachedBarHeight / 2.0f;
        mUnreachedRectF.bottom = getHeight()/2.0f  + mUnreachedBarHeight / 2.0f;
    }

    private void calculateDrawRectF(){

        mCurrentDrawText = String.format("%d" ,getProgress()*100/getMax());
        mCurrentDrawText = mPrefix + mCurrentDrawText + mSuffix;
        mDrawTextWidth = mTextPaint.measureText(mCurrentDrawText);

        if(getProgress() == 0){
            mDrawReachedBar = false;
            mDrawTextStart = getPaddingLeft();
        }else{
            mDrawReachedBar = true;
            mReachedRectF.left = getPaddingLeft();
            mReachedRectF.top = getHeight()/2.0f - mReachedBarHeight / 2.0f;
            mReachedRectF.right = (getWidth() - getPaddingLeft() - getPaddingRight() )/(getMax()*1.0f) * getProgress() - mOffset + getPaddingLeft();
            mReachedRectF.bottom = getHeight()/2.0f + mReachedBarHeight / 2.0f;
            mDrawTextStart = (mReachedRectF.right + mOffset);
        }

        mDrawTextEnd =  (int) ((getHeight() / 2.0f) - ((mTextPaint.descent() + mTextPaint.ascent()) / 2.0f)) ;

        if((mDrawTextStart + mDrawTextWidth )>= getWidth() - getPaddingRight()){
            mDrawTextStart = getWidth() - getPaddingRight() - mDrawTextWidth;
            mReachedRectF.right = mDrawTextStart - mOffset;
        }

        float unreachedBarStart = mDrawTextStart + mDrawTextWidth + mOffset;
        if(unreachedBarStart >= getWidth() - getPaddingRight()){
            mDrawUnreachedBar = false;
        }else{
            mDrawUnreachedBar = true;
            mUnreachedRectF.left = unreachedBarStart;
            mUnreachedRectF.right = getWidth() - getPaddingRight();
            mUnreachedRectF.top = getHeight()/2.0f +  - mUnreachedBarHeight / 2.0f;
            mUnreachedRectF.bottom = getHeight()/2.0f  + mUnreachedBarHeight / 2.0f;
        }
    }
    /**
     * get progress text color
     * @return progress text color
     */
    public int getTextColor() {
        return mTextColor;
    }

    /**
     * get progress text size
     * @return progress text size
     */
    public float getProgressTextSize() {
        return mTextSize;
    }

    public int getUnreachedBarColor() {
        return mUnreachedBarColor;
    }

    public int getReachedBarColor() {
        return mReachedBarColor;
    }

    public int getProgress() {
        return mProgress;
    }

    public int getMax() {
        return mMax;
    }

    public float getReachedBarHeight(){
        return mReachedBarHeight;
    }

    public float getUnreachedBarHeight(){
        return mUnreachedBarHeight;
    }

    public void setProgressTextSize(float TextSize) {
        this.mTextSize = TextSize;
        mTextPaint.setTextSize(mTextSize);
        invalidate();
    }

    public void setProgressTextColor(int TextColor) {
        this.mTextColor = TextColor;
        mTextPaint.setColor(mTextColor);
        invalidate();
    }

    public void setUnreachedBarColor(int BarColor) {
        this.mUnreachedBarColor = BarColor;
        mUnreachedBarPaint.setColor(mReachedBarColor);
        invalidate();
    }

    public void setReachedBarColor(int ProgressColor) {
        this.mReachedBarColor = ProgressColor;
        mReachedBarPaint.setColor(mReachedBarColor);
        invalidate();
    }

    public void setReachedBarHeight(float height){
        mReachedBarHeight = height;
    }

    public void setUnreachedBarHeight(float height){
        mUnreachedBarHeight = height;
    }

    public void setMax(int Max) {
        if(Max > 0){
            this.mMax = Max;
            invalidate();
        }
    }

    public void setSuffix(String suffix){
        if(suffix == null){
            mSuffix = "";
        }else{
            mSuffix = suffix;
        }
    }

    public String getSuffix(){
        return mSuffix;
    }

    public void setPrefix(String prefix){
        if(prefix == null)
            mPrefix = "";
        else{
            mPrefix = prefix;
        }
    }

    public String getPrefix(){
        return mPrefix;
    }

    public void incrementProgressBy(int by){
        if(by > 0){
            setProgress(getProgress() + by);
        }
    }

    public void setProgress(int Progress) {
        if(Progress <= getMax()  && Progress >= 0){
            this.mProgress = Progress;
            invalidate();
        }
    }

    @Override
    protected Parcelable onSaveInstanceState() {
        final Bundle bundle = new Bundle();
        bundle.putParcelable(INSTANCE_STATE,super.onSaveInstanceState());
        bundle.putInt(INSTANCE_TEXT_COLOR,getTextColor());
        bundle.putFloat(INSTANCE_TEXT_SIZE, getProgressTextSize());
        bundle.putFloat(INSTANCE_REACHED_BAR_HEIGHT,getReachedBarHeight());
        bundle.putFloat(INSTANCE_UNREACHED_BAR_HEIGHT,getUnreachedBarHeight());
        bundle.putInt(INSTANCE_REACHED_BAR_COLOR,getReachedBarColor());
        bundle.putInt(INSTANCE_UNREACHED_BAR_COLOR,getUnreachedBarColor());
        bundle.putInt(INSTANCE_MAX,getMax());
        bundle.putInt(INSTANCE_PROGRESS,getProgress());
        bundle.putString(INSTANCE_SUFFIX,getSuffix());
        bundle.putString(INSTANCE_PREFIX,getPrefix());
        bundle.putBoolean(INSTANCE_TEXT_VISBILITY, getProgressTextVisibility());
        return bundle;
    }

    @Override
    protected void onRestoreInstanceState(Parcelable state) {
        if(state instanceof Bundle){
            final Bundle bundle = (Bundle)state;
            mTextColor = bundle.getInt(INSTANCE_TEXT_COLOR);
            mTextSize = bundle.getFloat(INSTANCE_TEXT_SIZE);
            mReachedBarHeight = bundle.getFloat(INSTANCE_REACHED_BAR_HEIGHT);
            mUnreachedBarHeight = bundle.getFloat(INSTANCE_UNREACHED_BAR_HEIGHT);
            mReachedBarColor = bundle.getInt(INSTANCE_REACHED_BAR_COLOR);
            mUnreachedBarColor = bundle.getInt(INSTANCE_UNREACHED_BAR_COLOR);
            initializePainters();
            setMax(bundle.getInt(INSTANCE_MAX));
            setProgress(bundle.getInt(INSTANCE_PROGRESS));
            setPrefix(bundle.getString(INSTANCE_PREFIX));
            setSuffix(bundle.getString(INSTANCE_SUFFIX));
            setProgressTextVisibility(bundle.getBoolean(INSTANCE_TEXT_VISBILITY) ? ProgressTextVisibility.Visible : ProgressTextVisibility.Invisible);
            super.onRestoreInstanceState(bundle.getParcelable(INSTANCE_STATE));
            return;
        }
        super.onRestoreInstanceState(state);
    }

    public float dp2px(float dp) {
        final float scale = getResources().getDisplayMetrics().density;
        return  dp * scale + 0.5f;
    }

    public float sp2px(float sp){
        final float scale = getResources().getDisplayMetrics().scaledDensity;
        return sp * scale;
    }

    public void setProgressTextVisibility(ProgressTextVisibility visibility){
        mIfDrawText = visibility == ProgressTextVisibility.Visible;
        invalidate();
    }

    public boolean getProgressTextVisibility() {
        return mIfDrawText;
    }

}

Link 1

Link 2

Link 3

Link 4

Link 5

Link 6

您也可以使用线性布局来实现。我做了一个简单的例子，只是一个简单的例子。

<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" >

    <LinearLayout
        android:id="@+id/ll_progress"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:background="@drawable/layout" >

        <ImageView
            android:id="@+id/ImageView01"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="10dp"
            android:layout_marginTop="14dp"
            android:src="@drawable/bg_1" />

        <ImageView
            android:id="@+id/imageView1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="38dp"
            android:layout_marginTop="14dp"
            android:src="@drawable/bg_1" />


        <ImageView
            android:id="@+id/imageView12"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="35dp"
            android:layout_marginTop="14dp"
            android:src="@drawable/bg_1" />

    </LinearLayout>

</RelativeLayout>

主 Activity .java

import java.util.concurrent.TimeUnit;

import android.app.Activity;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.TransitionDrawable;
import android.os.Bundle;
import android.os.Handler;
import android.widget.ImageView;
import android.widget.LinearLayout;

public class MainActivity extends Activity {

    LinearLayout llProgress;
    Handler handler;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        llProgress = (LinearLayout) findViewById(R.id.ll_progress);
        handler = new Handler(getMainLooper());

        startTransition();
    }

    int prevChild = 0;

    private void startTransition() {
        // create the transition layers
        Drawable[] layers = new Drawable[2];
        layers[0] = new BitmapDrawable(getResources(), BitmapFactory.decodeResource(getResources(), R.drawable.bg));
        layers[1] = new BitmapDrawable(getResources(), BitmapFactory.decodeResource(getResources(), R.drawable.bg_1));

        final TransitionDrawable[] transitionDrawable = new TransitionDrawable[llProgress.getChildCount()];
        for (int i = 0; i < llProgress.getChildCount(); i++) {
            transitionDrawable[i] = new TransitionDrawable(layers);
            ((ImageView) llProgress.getChildAt(i)).setImageDrawable(transitionDrawable[i]);
        }

        handler.postDelayed(new Runnable() {

            @Override
            public void run() {
                transitionDrawable[prevChild++].startTransition(1000);
                if(prevChild > llProgress.getChildCount() - 1){
                    prevChild = 0;
                }
                handler.postDelayed(this, 1000 * 3);
            }
        }, 1000 * 3);

    }

关于android - 状态进度条android，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/26598518/