原生Android画板（非签名），自带曲线，带箭头直线，框，文字，以及撤销功能

package com.example.wir.basetabproject.act; import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Matrix; import android.graphics.Paint; import android.graphics.Path; import android.graphics.Rect; import android.os.Bundle; import android.support.annotation.Nullable; import android.support.v4.content.ContextCompat; import android.text.Editable; import android.text.Layout; import android.text.StaticLayout; import android.text.TextPaint; import android.text.TextUtils; import android.text.TextWatcher; import android.util.DisplayMetrics; import android.util.Log; import android.view.Gravity; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.view.WindowManager; import android.view.inputmethod.InputMethodManager; import android.widget.EditText; import android.widget.ImageView; import android.widget.RelativeLayout; import android.widget.TextView; import android.widget.Toast; import com.example.wir.basetabproject.R; import com.example.wir.basetabproject.data.PaintData; import com.example.wir.basetabproject.utils.AppUtils; import java.util.ArrayList; /** * Created by jhs on 2018/1/10. */ public class SecondActivity extends Activity implements View.OnClickListener { private ImageView iv; private Bitmap bitmap, backgroud; //画纸和背景图 private Canvas canvas; //画布 private Paint paint; //画笔 private Path path; //储存已经写的笔画 private ArrayList<PaintData> savePath = new ArrayList<PaintData>(); private View v_red; private View v_blue; private TextView tv_return;//撤回 private TextView tv_line;//线 private TextView tv_arrow;//箭头 private TextView tv_frame;//框 private TextView tv_save;//保存 private TextView tv_txt;// int mColor = Color.RED; private RelativeLayout rl_base; TextPaint mTextPaint; //文字画笔 public final static int DRAW_TXT_SIZE = 15; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_second); iv = findViewById(R.id.iv); rl_base = findViewById(R.id.rl_base); v_red = findViewById(R.id.v_red); v_blue = findViewById(R.id.v_blue); tv_return = findViewById(R.id.tv_return); tv_line = findViewById(R.id.tv_line); tv_arrow = findViewById(R.id.tv_arrow); tv_frame = findViewById(R.id.tv_frame); tv_save = findViewById(R.id.tv_save); tv_txt = findViewById(R.id.tv_txt); v_red.setOnClickListener(this); v_blue.setOnClickListener(this); tv_return.setOnClickListener(this); tv_line.setOnClickListener(this); tv_arrow.setOnClickListener(this); tv_frame.setOnClickListener(this); tv_save.setOnClickListener(this); tv_txt.setOnClickListener(this); // bitmap = Bitmap.createBitmap(getWindowManager().getDefaultDisplay() // .getWidth(), getWindowManager().getDefaultDisplay().getHeight(), // Bitmap.Config.ARGB_8888); // canvas = new Canvas(bitmap);// 画板 paint = // iv.setImageBitmap(bitmap); // iv.setImageResource(R.drawable.iv_bg); //拿到背景图 // //拿到和背景图一样大小的画纸 // bitmap = Bitmap.createBitmap(getWindowManager().getDefaultDisplay() // .getWidth(), getWindowManager().getDefaultDisplay().getHeight(), // backgroud.getConfig()); // ChangeImageSize(this,iv,backgroud.getHeight(),backgroud.getWidth()); //拿到背景图 backgroud = BitmapFactory.decodeResource(getResources(), R.drawable.iv_bg); backgroud = getbitmap(backgroud, iv); ViewGroup.LayoutParams lp = rl_base.getLayoutParams(); lp.width = backgroud.getWidth(); lp.height = backgroud.getHeight(); rl_base.setLayoutParams(lp); initCanvas(); iv.setOnTouchListener(lineListener); } private void initPaint() { //拿到画笔 paint = new Paint(); paint.setColor(mColor);//设置画笔颜色为黑色 // 设置“空心”的外框的宽度 paint.setStrokeWidth(5); paint.setStyle(Paint.Style.STROKE); paint.setStrokeCap(Paint.Cap.ROUND); mTextPaint = new TextPaint(); mTextPaint.setColor(mColor); mTextPaint.setTextSize(AppUtils.dip2px(DRAW_TXT_SIZE, getBaseContext())); mTextPaint.setAntiAlias(true); } @Override public void onClick(View view) { showTxt(); switch (view.getId()) { case R.id.v_blue: mColor = Color.BLUE; paint.setColor(mColor); break; case R.id.v_red: mColor = Color.RED; paint.setColor(mColor); break; case R.id.tv_line: iv.setOnTouchListener(lineListener); break; case R.id.tv_arrow: iv.setOnTouchListener(arrowListener); break; case R.id.tv_frame: iv.setOnTouchListener(frameListener); break; case R.id.tv_txt: iv.setOnTouchListener(textListener); break; case R.id.tv_return: returnOne(); break; case R.id.tv_save: String path = AppUtils.saveMyBitmapForPath(this, bitmap); Toast.makeText(this, "保存至" + path, Toast.LENGTH_SHORT).show(); break; } } private void returnOne() { if (savePath != null && savePath.size() > 0) { initCanvas(); savePath.remove(savePath.size() - 1); for (PaintData data : savePath) { data.draw(canvas, getBaseContext()); } } } private void clearNew() { initCanvas(); if (savePath != null && savePath.size() > 0) { for (PaintData data : savePath) { data.draw(canvas, getBaseContext()); } } } @Override public void onBackPressed() { showTxt(); super.onBackPressed(); } //初始化画布 public void initCanvas() { initPaint(); bitmap = Bitmap.createBitmap(backgroud.getWidth(), backgroud.getHeight(), backgroud.getConfig()); // //把画纸固定在画布上 canvas = new Canvas(bitmap); // //添加处理规则 Matrix matrix = new Matrix(); // //照着背景图画 canvas.drawBitmap(backgroud, matrix, paint); iv.setImageBitmap(bitmap); } private View.OnTouchListener lineListener = new View.OnTouchListener() { private float mX, mY; @Override public boolean onTouch(View view, MotionEvent motionEvent) { float x = motionEvent.getX(); float y = motionEvent.getY(); switch (motionEvent.getAction()) { case MotionEvent.ACTION_DOWN: paint.setColor(mColor); path = new Path(); path.reset();//清空path path.moveTo(x, y); mX = x; mY = y; break; case MotionEvent.ACTION_MOVE: float dx = Math.abs(x - mX); float dy = Math.abs(y - mY); if (dx >= 4 || dy >= 4) {