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Android 自定义控件-自定义进度条。

Android 自定义控件-自定义进度条。

作者: 844b9a3a3a68 | 来源:发表于2017-05-22 12:03 被阅读3673次

    效果图:


    效果图

    1.编写类继承View

    public class ProgressBarView extends ProgressBar {
    }
    

    2.重写构造方法

        public ProgressBarView(Context context) {
            this(context, null);//这里调用本类的两个构造参数的构造方法
        }
    
        public ProgressBarView(Context context, AttributeSet attrs) {
            this(context, attrs, 0);//这里调用本类的三个构造参数的构造方法
        }
    
        public ProgressBarView(Context context, AttributeSet attrs, int defStyleAttr) {
            super(context, attrs, defStyleAttr);
            //由于前两个构造都最终调用了此构造方法,所以在这里写初始化方法
            init(attrs);
        }
    

    3.自定义属性

    <?xml version="1.0" encoding="utf-8"?>
    <resources>
        <attr name="progress_color" format="color"></attr>
        <attr name="progress_height" format="dimension"></attr>
        <attr name="progress_reach_color" format="color"></attr>
        <attr name="progress_reach_height" format="dimension"></attr>
        <attr name="progress_text_color" format="color"></attr>
        <attr name="progress_text_size" format="dimension"></attr>
        <attr name="progress_text_offset" format="dimension"></attr>
    
        <declare-styleable name="ProgressBarView">
            <attr name="progress_color"></attr>
            <attr name="progress_height"></attr>
            <attr name="progress_reach_color"></attr>
            <attr name="progress_reach_height"></attr>
            <attr name="progress_text_color"></attr>
            <attr name="progress_text_size"></attr>
            <attr name="progress_text_offset"></attr>
        </declare-styleable>
    
    </resources>
    

    4.声明需要的变量以及常量

        private static final int DEFAULT_TEXT_SIZE = 10;//默认文字大小
        private static final int DEFAULT_TEXT_COLOR = 0xFFFC00D1;//默认文字颜色
        private static final int DEFAULT_COLOR = 0xFFD3D6DA;//默认颜色
        private static final int DEFAULT_HEIGHT = 2;
        private static final int DEFAULT_REACH_COLOR = DEFAULT_TEXT_COLOR;
        private static final int DEFAULT_REACH_HEIGHT = 2;
        private static final int DEFAULT_TEXT_OFFSET = 10;
    
        private int mTextColor = DEFAULT_TEXT_COLOR;
        private int mHeight = dp2px(DEFAULT_HEIGHT);
        private int mReachColor = DEFAULT_REACH_COLOR;
        private int mReachHeight = dp2px(DEFAULT_REACH_HEIGHT);
        private int mColor = DEFAULT_COLOR;
        private int mTextSize = sp2px(DEFAULT_TEXT_SIZE);
        private int mTextOffset = dp2px(DEFAULT_TEXT_OFFSET);
    
        private Paint mPaint = new Paint();
        private int mRealWidth;
    

    5.测量View大小

        @Override
        protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    //        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
            int widthMode = MeasureSpec.getMode(widthMeasureSpec);//得到测量模式
            int widthVal = MeasureSpec.getSize(widthMeasureSpec);//默认用户需要给出明确值,所以不判断模式
            int height = measureHeight(heightMeasureSpec);
            setMeasuredDimension(widthVal, height);//设置了测量值后,可以获取测量值。
            mRealWidth = getMeasuredWidth() - getPaddingLeft() - getPaddingRight();
        }
    

    测量方法:

     /**
         * 测量高度
         *
         * @param heightMeasureSpec
         * @return
         */
        private int measureHeight(int heightMeasureSpec) {
            int result = 0;
            int mode = MeasureSpec.getMode(heightMeasureSpec);//得到测量模式
            int size = MeasureSpec.getSize(heightMeasureSpec);
            if (mode == MeasureSpec.EXACTLY) {//用户给了精确值
                result = size;
            } else { //MeasureSpec.UNSPECIFIED  MeasureSpec.AT_MOST 未指定明确参数
                int textHeight = (int) (mPaint.descent() - mPaint.ascent());//得到文字高度
                result = getPaddingTop() + getPaddingBottom() + Math.max(mHeight, Math.max(mReachHeight, Math.abs(textHeight)));//高度等于进度条高度和文字高度中最高的为准,并且加上padding值
                if (mode == MeasureSpec.AT_MOST) {//给定了最大值
                    result = Math.min(result, size);
                }
            }
    
            return result;
        }
    

    6.获取自定义属性

        /**
         * 获取自定义属性
         */
        private void init(AttributeSet attrs) {
            TypedArray ta = getContext().obtainStyledAttributes(attrs, R.styleable.ProgressBarView);
            mTextColor = ta.getColor(R.styleable.ProgressBarView_progress_color, mTextColor);
            mHeight = (int) ta.getDimension(R.styleable.ProgressBarView_progress_height, mHeight);
            mReachColor = ta.getColor(R.styleable.ProgressBarView_progress_reach_color, mReachColor);
            mReachHeight = (int) ta.getDimension(R.styleable.ProgressBarView_progress_reach_height, mReachHeight);
            mColor = ta.getColor(R.styleable.ProgressBarView_progress_text_color, mColor);
            mTextSize = (int) ta.getDimension(R.styleable.ProgressBarView_progress_text_size, mTextSize);
            mTextOffset = (int) ta.getDimension(R.styleable.ProgressBarView_progress_text_offset, mTextOffset);
    
            ta.recycle();
            mPaint.setTextSize(mTextSize);//设定文字大小,后续好测量文字高度
        }
    

    附上单位转换工具类:

        private int dp2px(int val) {
            return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, val, getResources().getDisplayMetrics());
        }
    
        private int sp2px(int val) {
            return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, val, getResources().getDisplayMetrics());
        }
    

    7.绘制界面

        @Override
        protected synchronized void onDraw(Canvas canvas) {
    //        super.onDraw(canvas);
            canvas.save();
            canvas.translate(getPaddingLeft(), getHeight() / 2);//移动坐标到起点垂直居中位置
    
            //draw bar
    
            boolean noNeedUnRech = false;
    
            String text = getProgress() + "%";
            int textWidth = (int) mPaint.measureText(text);//测量进度值文本宽度
    
            float barWidth = mRealWidth - textWidth - mTextOffset;//先预留出文本宽度作为Bar总宽度
    //        if (getProgress() <= 0 || getProgress() >= 100) {
    //            barWidth = mRealWidth - textWidth - mTextOffset / 2;
    //        }
            float radio = getProgress() * 1.0f / getMax();//得到目前进度比例
            float currProgress = radio * barWidth;//当前进度在Bar总长度上占有的宽度
            if (currProgress >= barWidth) {//当前进度是否已经达到100
                currProgress = barWidth;//限制不能超过100
                noNeedUnRech = true;
            }
    
            if (currProgress > 0) {//进度大于0才绘制起始进度条
                mPaint.setColor(mColor);
                mPaint.setStrokeWidth(mHeight);
                if (noNeedUnRech) {//如果进度已经100,那么文字后边距将省略,用于充满进度条
                    currProgress += mTextOffset / 2;
                }
                canvas.drawLine(0, 0, currProgress, 0, mPaint);
            }
    
            //draw text
            mPaint.setColor(mTextColor);
            int y = (int) (-(mPaint.descent() + mPaint.ascent()) / 2);
            if (currProgress <= 0) {//进度低于0时,去除起始点文字边距
                canvas.drawText(text, currProgress, y, mPaint);
            } else {
                canvas.drawText(text, currProgress + mTextOffset / 2, y, mPaint);
            }
    
            //draw unreach bar
            if (!noNeedUnRech) {//如果进度未满才绘制结束Bar
                float start = currProgress + mTextOffset + textWidth;
                if (currProgress <= 0) {//进度低于0时,去除起始点文字边距
                    start = start - mTextOffset / 2;
                }
                mPaint.setColor(mReachColor);
                mPaint.setStrokeWidth(mReachHeight);
                canvas.drawLine(start, 0, mRealWidth, 0, mPaint);
            }
    
    
            canvas.restore();
        }
    

    8.使用
    声明命名空间

     xmlns:chao="http://schemas.android.com/apk/res-auto"
    

    引入控件

        <com.example.chao.progressbar.ProgressBarView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:padding="15dp"
            android:progress="50" />
    
        <com.example.chao.progressbar.ProgressBarView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:padding="15dp"
            android:progress="30"
            chao:progress_text_color="#ff0000" />
    
        <com.example.chao.progressbar.ProgressBarView
            android:id="@+id/progress"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:background="#3090ff50"
            android:padding="15dp"
            android:progress="66"
            chao:progress_color="#000"
            chao:progress_height="2dp"
            chao:progress_reach_color="#f0f"
            chao:progress_reach_height="1dp"
            chao:progress_text_color="#f00"
            chao:progress_text_offset="10dp"
            chao:progress_text_size="12dp" />
    

    效果图:


    效果图

    代码动态更新进度:

    progress.setProgress(i++);
    

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