android实现手写签名功能

本文实例为大家分享了android手写签名展示的具体代码，供大家参考，具体内容如下

代码简单，就不发demo了，直接贴代码

package com.xx;
 
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.frameLayout;
import android.widget.ImageView;
import com.xx.R;
 

public class SignatureActivity extends AppCompatActivity {
 
 private ImageView imageSign;
 private SignatureView mView;
 
 @Override public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_signature);
 
  imageSign = findViewById(R.id.iv_sign);
  frameLayout frameLayout = findViewById(R.id.fl_view);
 
  mView = new SignatureView(this);
  frameLayout.addView(mView);
  mView.requestFocus();
 
  Button btnClear = findViewById(R.id.btn_clear);
  btnClear.setonClickListener((v) -> {
    mView.clear();
  });
 
  Button btnOk = findViewById(R.id.btn_ok);
  btnOk.setonClickListener((v) -> {
    Bitmap imageBitmap = mView.getCachebBitmap();
    imageSign.setImageBitmap(imageBitmap);
  });
 }
 
 
 class SignatureView extends View {
 
  //画笔
  private Paint paint;
 
  //画布
  private Canvas cacheCanvas;
 
  //位图
  private Bitmap cachebBitmap;
 
  //图片保存路径
  private Path path;
 
  //位图缓存
  public Bitmap getCachebBitmap() {
   return cachebBitmap;
  }
 
  public SignatureView(Context context) {
   super(context);
   init();
  }
 
  
  private void init() {
   //设置画笔
   paint = new Paint();
   paint.setAntiAlias(true);
   paint.setStrokeWidth(3);
   paint.setStyle(Paint.Style.STROKE);
   paint.setColor(Color.BLACK);
   path = new Path();
 
   //创建位图
   cachebBitmap = Bitmap.createBitmap(10, 10, Bitmap.Config.ARGB_8888);
 
   //用自定义位图构建画布
   cacheCanvas = new Canvas(cachebBitmap);
   //设置画布为白色
   cacheCanvas.drawColor(Color.WHITE);
  }
 
  
  public void clear() {
   if (cacheCanvas != null) {
    paint.setColor(Color.WHITE);
    cacheCanvas.drawPaint(paint);
    paint.setColor(Color.BLACK);
    cacheCanvas.drawColor(Color.WHITE);
    invalidate();
   }
  }
 
  @Override protected void onDraw(Canvas canvas) {
   canvas.drawBitmap(cachebBitmap, 0, 0, null);
   canvas.drawPath(path, paint);
  }
 
  @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) {
 
   int curW = cachebBitmap != null ? cachebBitmap.getWidth() : 0;
   int curH = cachebBitmap != null ? cachebBitmap.getHeight() : 0;
   if (curW >= w && curH >= h) {
    return;
   }
 
   if (curW < w) curW = w;
   if (curH < h) curH = h;
   Bitmap newBitmap = Bitmap.createBitmap(curW, curH, Bitmap.Config.ARGB_8888);
   Canvas newCanvas = new Canvas();
   newCanvas.setBitmap(newBitmap);
   if (cachebBitmap != null) {
    newCanvas.drawBitmap(cachebBitmap, 0, 0, null);
   }
   cachebBitmap = newBitmap;
   cacheCanvas = newCanvas;
  }
  private float cur_x, 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;
    }
   }
   invalidate();
   return true;
  }
 }
}

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