自定义控件之实现在线签名,保存,清除等功能实现

不多说,直接上代码看效果:

package com.loaderman.signaturedemo;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;



public class SignatureView extends View {
    private Path mPath = new Path();
    private Paint mPaint;
    private float mPreX,mPreY;
    public SignatureView(Context context) {
        super(context);
        init();
    }

    public SignatureView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public SignatureView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        mPaint = new Paint();
        mPaint.setColor(Color.BLACK);
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setStrokeWidth(10);
    }
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()){
            case MotionEvent.ACTION_DOWN:{
                mPath.moveTo(event.getX(),event.getY());
                mPreX = event.getX();
                mPreY = event.getY();
                return true;
            }
            case MotionEvent.ACTION_MOVE:{
                float endX = (mPreX+event.getX())/2;
                float endY = (mPreY+event.getY())/2;
                mPath.quadTo(mPreX,mPreY,endX,endY);//实现手势平滑过渡
                mPreX = event.getX();
                mPreY =event.getY();
                invalidate();
            }
            break;
            default:
                break;
        }
        return super.onTouchEvent(event);
    }
    Canvas canvas;
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        this.canvas=canvas;
        canvas.drawColor(Color.WHITE);
        canvas.drawPath(mPath,mPaint);
    }

    public void clearDraw(){
        if (mPath!=null){
            mPath.reset();
            invalidate();
        }
    }

}

package com.loaderman.signaturedemo;

import android.os.Environment;

import java.io.File;


public class FileUtil {
    public static File getFile() {
        File appDir = new File(Environment.getExternalStorageDirectory(), "Signature");

        if (!appDir.exists()) {
            appDir.mkdirs();
        }
        return appDir;
    }
}

package com.loaderman.signaturedemo;

import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ImageView;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

public class MainActivity extends AppCompatActivity {

    private ImageView iv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        findViewById(R.id.tv_start).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                startActivity(new Intent(MainActivity.this, SignatureActivity.class));
            }
        });
        iv = findViewById(R.id.iv);
    }

    @Override
    protected void onResume() {
        super.onResume();
        Bitmap loacalBitmap = getLoacalBitmap(new File(FileUtil.getFile(), "signature.png"));
        if (loacalBitmap != null) {
            iv.setImageBitmap(loacalBitmap);
        }
    }

    /**
     * 加载本地图片
     *
     * @param file
     * @return
     */
    public static Bitmap getLoacalBitmap(File file) {
        try {
            FileInputStream fis = new FileInputStream(file);
            return BitmapFactory.decodeStream(fis);  ///把流转化为Bitmap图片

        } catch (FileNotFoundException e) {
            e.printStackTrace();
            return null;
        }
    }
}

package com.loaderman.signaturedemo;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Toast;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class SignatureActivity extends AppCompatActivity {

    private SignatureView sv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_signature);
        sv = findViewById(R.id.sv);
        findViewById(R.id.btn_ok).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Bitmap bitmap = Bitmap.createBitmap(sv.getWidth(), sv.getHeight(),
                        Bitmap.Config.ARGB_8888);
                Canvas canvas = new Canvas(bitmap);
                //把view中的内容绘制在画布上
                sv.draw(canvas);
                boolean b = saveBitmap(bitmap);
                if (b){
                    finish();
                }else {
                    Toast.makeText(SignatureActivity.this,"保存失败",Toast.LENGTH_SHORT).show();
                }


            }
        });
        findViewById(R.id.btn_clear).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                sv.clearDraw();
            }
        });
    }

    /** 保存方法 */
    public boolean saveBitmap(Bitmap bm) {
        File f=new File(FileUtil.getFile(),"signature.png");
        if (f.exists()) {
            f.delete();
        }
        try {
            FileOutputStream out = new FileOutputStream(f);
            bm.compress(Bitmap.CompressFormat.PNG, 90, out);
            out.flush();
            out.close();
            return true;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            return false;
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }
    }


}

main布局:

<?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="com.loaderman.signaturedemo.MainActivity">
    <TextView
        android:id="@+id/tv_start"
        android:layout_width="match_parent"
        android:text="线上签名"
        android:gravity="center"
        android:textColor="@color/colorPrimary"
        android:textSize="18sp"
        android:textStyle="bold"
        android:background="#ddd"
        android:layout_height="40dp" />

   <ImageView
       android:id="@+id/iv"
       android:background="#666"
       android:layout_width="match_parent"
       android:layout_height="match_parent" />
</LinearLayout>

activity_signature.xml

<?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="com.loaderman.signaturedemo.SignatureActivity">

    <com.loaderman.signaturedemo.SignatureView
        android:id="@+id/sv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:background="@color/colorPrimary"
        android:gravity="center">

        <Button
            android:id="@+id/btn_ok"
            android:layout_width="wrap_content"
            android:layout_height="40dp"
            android:layout_margin="5dp"
            android:textColor="#fff"
            android:textStyle="bold"
            android:textSize="18sp"
            android:background="@color/colorAccent"
            android:text="确定" />

        <Button
            android:id="@+id/btn_clear"
            android:layout_width="wrap_content"
            android:layout_height="40dp"
            android:textColor="#fff"
            android:textStyle="bold"
            android:textSize="18sp"
            android:background="@color/colorAccent"
            android:text="重签" />
    </LinearLayout>


</LinearLayout>

添加储存权限,配置签名时手机横屏显示

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.loaderman.signaturedemo">
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".SignatureActivity"
           android:screenOrientation="landscape"
            ></activity>
    </application>

</manifest>

效果图:

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源代码:https://github.com/loaderman/signaturedemo  喜欢请star哦

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