100行Android代码轻松实现带动画柱状图

package com.lixiaodaoaaa.view.pieview;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;
import com.gcssloop.graphics.R;
import com.lixiaodaoaaa.uitls.DensityUtils;
/**************************************
* *** http://weibo.com/lixiaodaoaaa **
* *** create at 2017/5/18  23:45 ****
* ******* by:lixiaodaoaaa **********
**************************************/
public class PColumn extends View {
int MAX = 100;//最大
int corner = 40;
int data = 0;//显示的数
int tempData = 0;
int textPadding = 20;
Paint mPaint;
int mColor;
Context mContext;
public PColumn(Context context) {
super(context);
mContext = context;
}
public PColumn(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
mContext = context;
initPaint();
}
public PColumn(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
mContext = context;
initPaint();
}
private void initPaint() {
mPaint = new Paint();
mPaint.setAntiAlias(true);
mColor = mContext.getResources().getColor(R.color.colorPrimary);
mPaint.setColor(mColor);
}
@Override
public void draw(Canvas canvas) {
super.draw(canvas);
if (data == 0) {
mPaint.setTextSize(getWidth() / 2);
RectF oval3 = new RectF(0, getHeight() - DensityUtils.pxTodip(mContext, 20), getWidth(), getHeight());// 设置个新的长方形
canvas.drawRoundRect(oval3, DensityUtils.pxTodip(mContext, corner), DensityUtils.pxTodip(mContext, corner), mPaint);
canvas.drawText("0",
getWidth() * 0.5f - mPaint.measureText("0") * 0.5f,
getHeight() - DensityUtils.pxTodip(mContext, 20) - 2 * DensityUtils.pxTodip(mContext, textPadding),
mPaint);
return;
}
//防止数值很大的的时候，动画时间过长
int step = data / 100 + 1;
if (tempData < data - step) {
tempData = tempData + step;
} else {
tempData = data;
}
//画圆角矩形
String S = tempData + "";
//一个字和两,三个字的字号相同
if (S.length() < 4) {
mPaint.setTextSize(getWidth() / 2);
} else {
mPaint.setTextSize(getWidth() / (S.length() - 1));
}
float textH = mPaint.ascent() + mPaint.descent();
float MaxH = getHeight() - textH - 2 * DensityUtils.pxTodip(mContext, textPadding);
//圆角矩形的实际高度
float realH = MaxH / MAX * tempData;
RectF oval3 = new RectF(0, getHeight() - realH, getWidth(), getHeight());// 设置个新的长方形
canvas.drawRoundRect(oval3, DensityUtils.pxTodip(mContext, corner), DensityUtils.pxTodip(mContext, corner), mPaint);
//写数字
canvas.drawText(S,
getWidth() * 0.5f - mPaint.measureText(S) * 0.5f,
getHeight() - realH - 2 * DensityUtils.pxTodip(mContext, textPadding),
mPaint);
if (tempData != data) {
postInvalidate();
}
}
public void setData(int data, int MAX) {
this.data = data;
tempData = 0;
this.MAX = MAX;
postInvalidate();
}
}

/*
* Copyright 2016 GcsSloop
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*  http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Last modified 2016-10-02 00:22:33
*
*/
package com.lixiaodaoaaa.graphics;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import com.gcssloop.graphics.R;
import com.lixiaodaoaaa.view.pieview.PColumn;
public class MainActivity extends AppCompatActivity {
private PColumn column_one;
private PColumn column_two;
private PColumn column_three;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initAllViews();
}
private void initAllViews() {
column_one = (PColumn) findViewById(R.id.column_one);
column_two = (PColumn) findViewById(R.id.column_two);
column_three = (PColumn) findViewById(R.id.column_three);
column_one.setData(0, 100);
column_two.setData(30, 100);
column_three.setData(40, 100);
}
}

<?xml version="1.0" encoding="utf-8"? 
<LinearLayout
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"
android:layout_weight="1"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.lixiaodaoaaa.graphics.MainActivity"
<View
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="0.2"/ 
<com.lixiaodaoaaa.view.pieview.PColumn
android:id="@+id/column_one"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"/ 
<View
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="2.4"/ 
<com.lixiaodaoaaa.view.pieview.PColumn
android:id="@+id/column_two"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"/ 
<View
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="2.4"/ 
<com.lixiaodaoaaa.view.pieview.PColumn
android:id="@+id/column_three"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"/ 
<View
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="0.2"/ 
</LinearLayout