Android自定义水平渐变进度条
时间：2020-11-06 10:06:51 | 栏目：Android代码 | 点击：次
先看进度条的效果：
具体实现：
新建类，继承自View，在onDraw中进行绘制：
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.Shader;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
/**
*
* 自定义 进度条
* Created by wenjing.tang on 2017/8/7.
*/
public class CustomizedProgressBar extends View {
private float maxCount = 100; //进度条最大值
private float currentCount; //进度条当前值
// private Paint mPaint ;
private int mWidth,mHeight;
private Context mContext;
public CustomizedProgressBar(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initView(context);
}
public CustomizedProgressBar(Context context, AttributeSet attrs) {
super(context, attrs);
initView(context);
}
public CustomizedProgressBar(Context context) {
super(context);
initView(context);
}
private void initView(Context context) {
mContext=context;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Paint mPaint = new Paint();
mPaint.setAntiAlias(true);
int round = mHeight/2; //半径
mPaint.setColor(getResources().getColor(R.color.white_alpha)); //设置边框背景颜色
RectF rectBg = new RectF(0, 0, mWidth, mHeight);
canvas.drawRoundRect(rectBg, round, round, mPaint);//绘制 最外面的大 圆角矩形，背景为白色
float section = currentCount/maxCount; //进度条的比例
RectF rectProgressBg = new RectF(0, 0, mWidth*section, mHeight);
Log.e("CustomizedProgressBar", currentCount+"");
Log.e("CustomizedProgressBar", section+"");
//Paint设置setColor(白色无透明)和setShader，只让setShader生效；不然前面setColor设置了透明度，透明度会生效，和setShader效果叠加
mPaint.setColor(getResources().getColor(R.color.white));
mPaint.setShader(getLinearGradient());
canvas.drawRoundRect(rectProgressBg, round, round, mPaint); //最左边的圆角矩形
if (maxCount != currentCount){ //如果不是100%，绘制第三段矩形
RectF rectProgressBg2 = new RectF(mWidth*section-round, 0, mWidth*section, mHeight);
mPaint.setShader(getLinearGradient());
canvas.drawRect(rectProgressBg2, mPaint);
}
}
private LinearGradient linearGradient;
private LinearGradient getLinearGradient(){
if(linearGradient==null){
linearGradient = new LinearGradient(0, 0, getWidth(), mHeight, new int[]{mContext.getResources().getColor(R.color.progress_color_1),
mContext.getResources().getColor(R.color.progress_color_2)}, null, Shader.TileMode.CLAMP); //根据R文件中的id获取到color
}
return linearGradient;
}
private int dipToPx(int dip) {
float scale = getContext().getResources().getDisplayMetrics().density;
return (int) (dip * scale + 0.5f * (dip >= 0 ? 1 : -1));
}
/***
* 设置最大的进度值
* @param maxCount 最大的进度值
*/
public void setMaxCount(float maxCount) {
this.maxCount = maxCount;
}
/***
* 设置当前的进度值
* @param currentCount 当前进度值
*/
public void setCurrentCount(float currentCount) {
this.currentCount = currentCount > maxCount ? maxCount : currentCount;
invalidate();
}
public float getMaxCount() {
return maxCount;
}
public float getCurrentCount() {
return currentCount;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);
int widthSpecSize = MeasureSpec.getSize(widthMeasureSpec);
int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSpecSize = MeasureSpec.getSize(heightMeasureSpec);
if (widthSpecMode == MeasureSpec.EXACTLY || widthSpecMode == MeasureSpec.AT_MOST) {
mWidth = widthSpecSize;
} else {
mWidth = 0;
}
if (heightSpecMode == MeasureSpec.AT_MOST || heightSpecMode == MeasureSpec.UNSPECIFIED) {
mHeight = dipToPx(18);
} else {
mHeight = heightSpecSize;
}
setMeasuredDimension(mWidth, mHeight);
}
}
其中用到的一些资源文件如下：
<!--自定义进度条背景颜色--> <color name="white_alpha">#0c000000</color> <!--自定义进度条渐变颜色--> <color name="progress_color_1">#ff916b</color> <color name="progress_color_2">#ffa94c</color>
要注意的是，在上面Java代码中，mPaint.setColor(getResources().getColor(R.color.white));这行很重要，因为进度条总共有三层，第一层是最外面的背景，第二层是进度，第三层如果不是100%才绘制，由于第一层背景有透明度，所以setColor设置了透明度，但虽然setShader，透明度还是会生效，两者效果叠加，效果是这样：
加上之后，Paint 第二次设置 setColor (白色无透明)和 setShader，只让 setShader 生效，进度条才会达到满意的效果；
用法：
Java代码中：
customizedProgressBar.setMaxCount(100);
integrity = dataCount/TOTAL_COUNT *100; //根据自己情况来初始化完整度
customizedProgressBar.setCurrentCount((int) integrity);
mTvtDataIntegrity.setText("完整度" + (int) integrity +"%");
xml文件中（不需要文字显示也可以）：
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="18dp"
android:layout_marginStart="66dp"
android:layout_marginEnd="66dp"
android:layout_centerVertical="true">
<com.text.widget.CustomizedProgressBar
android:id="@+id/progress"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true"/>
<TextView
android:id="@+id/tv_data_integrity"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
tools:text="完整度35%"
android:textSize="10sp"
android:layout_centerInParent="true"/>
</RelativeLayout>