在app端手写签名并保存下来（以文件形式或者是base64编码）_手寫簽名功能db用什麼字段保存

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 stub
        paint = 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);*/
    }
 
    @Override
    protected 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);
    }
 
    @Override
    protected void onDraw(Canvas canvas) {
        Paint bmpPaint = new Paint();
        canvas.drawBitmap(cachebBitmap, 0, 0, bmpPaint);
        canvas.drawPath(path, paint);
    }
 
    float cur_x;
    float cur_y;
 
    @Override
    public 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<DataBean> mDatas = new ArrayList<>();
    private HandWriteView handWriteView;
    private ImageView imageview;
    private String base64;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
 
//        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
        setContentView(R.layout.activity_main);
 
       /* dashview=findViewById(R.id.dashview);
        ArrayList<String> 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() {
            @Override
            public void onClick(View v) {
                handWriteView.clearCanvas();
                imageview.setVisibility(View.GONE);
            }
        });
        findViewById(R.id.btn_save).setOnClickListener(new View.OnClickListener() {
            @Override
            public 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() {
            @Override
            public 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：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">
 
    <!--<com.xuganwen.testandroidpie.MyPieView
        android:layout_width="200dp"
        android:layout_height="120dp"
        android:id="@+id/pieView"
        android:visibility="gone"
        android:layout_marginTop="10dp"/>
    <com.xuganwen.testandroidpie.DashBoardVIew
        android:layout_width="120dp"
        android:id="@+id/dashview"
        android:layout_height="120dp" />-->
 
    <Button
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:id="@+id/btn_clear"
        android:text="清除"
        />
 
    <Button
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:id="@+id/btn_save"
        android:text="保存"
        />
 
    <Button
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:id="@+id/btn_show"
        android:text="回显"
        />
 
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <com.xuganwen.testandroidpie.HandWriteView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/handwrite"
            />
        <ImageView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:visibility="gone"
            android:id="@+id/imageview"/>
 
    </RelativeLayout>
 
 
 
</LinearLayout>

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。。。