在app端手写签名并保存下来（以文件形式或者是base64编码）

最近做的项目有个需求，在app端手写签名的并保存为文件或者base64编码。所以就刚好有时间写了一下并记录下来：

先上效果图：

分析思路：因为这里是要获取手势轨迹并画出来，所以肯定是有个Touch事件，然后使用要回显，那肯定是要获取所画的内容，所以想到了canvas这个东西，那这样就选择了自定义控件来做了。

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PorterDuff;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;/*** 文件描述：* 作者：徐干稳* 创建时间：2019/11/21* 更改时间：2019/11/21* 版本号：1.0*/
public class HandWriteView extends View {private Paint paint;private Path path;public Bitmap cachebBitmap;private Canvas cacheCanvas;private boolean clearFlag = false;public HandWriteView(Context context) {this(context, null);}public HandWriteView(Context context, AttributeSet attrs) {super(context, attrs);// TODO Auto-generated constructor stubpaint = new Paint();paint.setAntiAlias(true);paint.setStrokeWidth(3);paint.setStyle(Paint.Style.STROKE);paint.setColor(Color.BLACK);path = new Path();/*cachebBitmap = Bitmap.createBitmap(1080, 1800, Config.ARGB_8888);cacheCanvas = new Canvas(cachebBitmap);cacheCanvas.drawColor(Color.WHITE);*/}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);cachebBitmap = Bitmap.createBitmap(getMeasuredWidth(), getMeasuredHeight(), Config.ARGB_8888);cacheCanvas = new Canvas(cachebBitmap);cacheCanvas.drawColor(Color.WHITE);}@Overrideprotected void onDraw(Canvas canvas) {Paint bmpPaint = new Paint();canvas.drawBitmap(cachebBitmap, 0, 0, bmpPaint);canvas.drawPath(path, paint);}float cur_x;float cur_y;@Overridepublic boolean onTouchEvent(MotionEvent event) {float x = event.getX();float y = event.getY();switch (event.getAction()) {case MotionEvent.ACTION_DOWN:cur_x = x;cur_y = y;path.moveTo(cur_x, cur_y);break;case MotionEvent.ACTION_MOVE:path.quadTo(cur_x, cur_y, x, y);cur_x = x;cur_y = y;break;case MotionEvent.ACTION_UP:cacheCanvas.drawPath(path, paint);path.reset();break;default:break;}invalidate();return true;}/*** 清除画布内容*/public void clearCanvas() {cacheCanvas.drawColor(Color.WHITE, PorterDuff.Mode.SRC_OVER);invalidate();}
}

主界面代码：

package com.xuganwen.testandroidpie;import android.content.pm.ActivityInfo;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Base64;
import android.view.View;
import android.widget.ImageView;
import android.widget.Toast;import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;public class MainActivity extends AppCompatActivity {private MyPieView pieView;private List mDatas = new ArrayList<>();private HandWriteView handWriteView;private ImageView imageview;private String base64;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);//        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);setContentView(R.layout.activity_main);/* dashview=findViewById(R.id.dashview);ArrayList strings = new ArrayList<>();strings.add("10.0");strings.add("7.5");strings.add("5.0");strings.add("2.5");dashview.setArrowRotateDrgee(135);dashview.setValues(strings);dashview.setCurrentValue(2.2f);dashview.invalidate();*/handWriteView = findViewById(R.id.handwrite);findViewById(R.id.btn_clear).setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {handWriteView.clearCanvas();imageview.setVisibility(View.GONE);}});findViewById(R.id.btn_save).setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {ByteArrayOutputStream outputStream = new ByteArrayOutputStream();handWriteView.cachebBitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);byte[] buffer = outputStream.toByteArray();base64 = byteToBase64(buffer);
//                Toast.makeText(getApplicationContext(),base64+"",Toast.LENGTH_SHORT).show();}});findViewById(R.id.btn_show).setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (null != base64) {imageview.setVisibility(View.VISIBLE);byte[] decode = Base64.decode(base64.split(",")[1], Base64.DEFAULT);Bitmap bitmap = BitmapFactory.decodeByteArray(decode, 0, decode.length);imageview.setImageBitmap(bitmap);}}});imageview = findViewById(R.id.imageview);}public static String byteToBase64(byte[] bytes) {String base64 = null;InputStream in = null;try {in = new ByteArrayInputStream(bytes);base64 = "data:image/png;base64," + android.util.Base64.encodeToString(bytes, Base64.DEFAULT);} catch (Exception e) {e.printStackTrace();} finally {if (in != null) {try {in.close();} catch (IOException e) {e.printStackTrace();}}}return base64;}/*** base64显示为图片*/public void showBase64ToImage(ImageView imageView, String base64) {if (null != imageView && null != base64) {byte[] decode = Base64.decode(base64.split(",")[1], Base64.DEFAULT);Bitmap bitmap = BitmapFactory.decodeByteArray(decode, 0, decode.length);imageView.setImageBitmap(bitmap);}}/*** cachebitmap转文件存储下来*/public void saveToFile() {ByteArrayOutputStream outputStream = new ByteArrayOutputStream();handWriteView.cachebBitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);byte[] buffer = outputStream.toByteArray();if (buffer != null) {try {File file = new File(Environment.getExternalStorageDirectory(), "sign.jpg");file.createNewFile();new FileOutputStream(file).write(buffer);} catch (Exception e) {e.printStackTrace();}}Toast.makeText(this, "生成图片文件", Toast.LENGTH_SHORT).show();}}

布局代码：

以上就是图片中显示效果的所有代码，几年前写的东西没想到今天会用到项目中，所以在这里记录下来，说不定以后还能用到。。。

本文来自互联网用户投稿，文章观点仅代表作者本人，不代表本站立场，不承担相关法律责任。如若转载，请注明出处。 如若内容造成侵权/违法违规/事实不符，请点击【内容举报】进行投诉反馈！