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2018-03-19 图片处理(六)----自定义画板

2018-03-19 图片处理(六)----自定义画板

作者: 紫杉叶子 | 来源:发表于2018-03-20 09:35 被阅读0次

笔记如下



如图:
Video_2018-03-19_104911.gif

  • 实现步骤:
    首先是布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.chen.panel.MainActivity">

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <View
            android:onClick=""
            android:id="@+id/color_red"
            android:background="#ff0000"
            android:layout_width="35dp"
            android:layout_height="35dp"/>



        <View
            android:id="@+id/color_green"
            android:background="#00ff00"
            android:layout_width="35dp"
            android:layout_height="35dp"/>



        <View
            android:id="@+id/color_blue"
            android:background="#0000ff"
            android:layout_width="35dp"
            android:layout_height="35dp"/>



        <View
            android:id="@+id/color_yellow"
            android:background="#ffff00"
            android:layout_width="35dp"
            android:layout_height="35dp"/>



        <View
            android:id="@+id/color_pink"
            android:background="#ff99ff"
            android:layout_width="35dp"
            android:layout_height="35dp"/>

    </LinearLayout>
    
    <!--画笔 -->
    <SeekBar
        android:id="@+id/skb_stroke"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />
    <ImageView
        android:id="@+id/iv"
        android:layout_width="200dp"
        android:layout_height="200dp"
        />

    <Button
        android:onClick="save"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="保存图片"
        />

</LinearLayout>

调节颜色的方法

    protected void onCreate(Bundle savedInstanceState) {

      .............

        color_red.setOnClickListener(this);
        color_green.setOnClickListener(this);
        color_blue.setOnClickListener(this);
        color_pink.setOnClickListener(this);
        color_yellow.setOnClickListener(this);

      ...........


}

    //点击换颜色的点击事件
    @Override
    public void onClick(View v) {

        switch(v.getId()){
            //更改画笔的颜色
            case R.id.color_red:
                paint.setColor(Color.RED);
                break;
            case R.id.color_yellow:
                paint.setColor(Color.YELLOW);
                break;
            case R.id.color_green:
                paint.setColor(Color.GREEN);
                break;
            case R.id.color_blue:
                paint.setColor(Color.BLUE);
                break;
            case R.id.color_pink:
                paint.setColor(0xffff99ff);
                break;
            default:
                break;

        }

    }

ImageView的触摸事件


    float startX = 0;
    float startY = 0;
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        //触摸ImageView的回调
        //触摸的时候绘制我们的图像,并且显示
        /*
            Touch时有三种情况:event.getAction()
            1.手指按下
            2.手指移动
            3.手指抬起
         */


        switch (event.getAction()){
            case MotionEvent.ACTION_DOWN://1次
                //1.手指按下
                startX = event.getX();//触摸的x坐标
                startY = event.getY();//触摸的y坐标

//                startX = event.getRawX();
//                startY = event.getRawY();


                break;
            case MotionEvent.ACTION_MOVE://0-多次
                //2.手指移动
                //绘制图像,并显示到ImageView上
                float stopX = event.getX();
                float stopY = event.getY();
//                float stopX = event.getRawX();
//                float stopY = event.getRawY();

                System.out.println("x :" + stopX + "  y : " + stopY);

                canvas.drawLine(startX,startY,stopX,stopY,paint);

                iv.setImageBitmap(bitmap);

                startX = stopX;
                startY = stopY;

                break;
            case MotionEvent.ACTION_UP://1次
                //3.手指抬起


                break;
            default:
                break;
        }



        return true;

    }

seeBar的调节画笔大小的stop事件

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {
        //改变画笔的粗细
        int progress = seekBar.getProgress();
        //paint.setStrokeWidth(progress);
        paint.setStrokeWidth(10 * progress /100f + 0.5f);

    }



完整源码:
package com.chen.panel;

import android.Manifest;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.os.Environment;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.DisplayMetrics;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;
import android.widget.SeekBar;
import android.widget.Toast;

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

public class MainActivity extends AppCompatActivity implements View.OnClickListener, SeekBar.OnSeekBarChangeListener, View.OnTouchListener {

    private View color_red;
    private View color_green;
    private View color_yellow;
    private View color_blue;
    private View color_pink;

    private SeekBar skb_stroke;
    private ImageView iv;

    private Bitmap bitmap;
    private Canvas canvas;
    private Paint paint;

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

        color_red = findViewById(R.id.color_red);
        color_green = findViewById(R.id.color_green);
        color_yellow = findViewById(R.id.color_yellow);
        color_blue = findViewById(R.id.color_blue);
        color_pink = findViewById(R.id.color_pink);

        skb_stroke = (SeekBar) findViewById(R.id.skb_stroke);
        iv = (ImageView) findViewById(R.id.iv);

        color_red.setOnClickListener(this);
        color_green.setOnClickListener(this);
        color_blue.setOnClickListener(this);
        color_pink.setOnClickListener(this);
        color_yellow.setOnClickListener(this);
        skb_stroke.setOnSeekBarChangeListener(this);

        iv.setOnTouchListener(this);


        DisplayMetrics metrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(metrics);

        float density = metrics.density;
        System.out.println(density);

        //先准备我们的画板
        bitmap = Bitmap.createBitmap((int) (200*density), (int) (200*density), Bitmap.Config.ARGB_8888);
        //准备画纸
        canvas = new Canvas(bitmap);
        //画布默认是黑底的,所以要一开始画成白底的
        canvas.drawColor(Color.WHITE);
        //准备画笔
        paint = new Paint();


    }

    private void requestPermission(){
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED){ //表示未授权时
            //进行授权
            ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},1);
        }else{
            //调用打电话的方法
            Toast.makeText(this, "权限已经申请了.", Toast.LENGTH_SHORT).show();
        }
    }

    //保存图片
    public void save(View view){

        //File file = new File(Environment.getDataDirectory()+"/data/com.chen.panel/"+System.currentTimeMillis()+".jpg");

        File file = new File(Environment.getExternalStorageDirectory()+"/"+System.currentTimeMillis()+".jpg");

        FileOutputStream out = null;
        try {

            out = new FileOutputStream(file);
            //压缩到流中
            bitmap.compress(Bitmap.CompressFormat.JPEG,100,out);

        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            if (out != null){
                try {
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                out = null;
            }

        }

    }

    //点击换颜色的点击事件
    @Override
    public void onClick(View v) {

        switch(v.getId()){
            //更改画笔的颜色
            case R.id.color_red:
                paint.setColor(Color.RED);
                break;
            case R.id.color_yellow:
                paint.setColor(Color.YELLOW);
                break;
            case R.id.color_green:
                paint.setColor(Color.GREEN);
                break;
            case R.id.color_blue:
                paint.setColor(Color.BLUE);
                break;
            case R.id.color_pink:
                paint.setColor(0xffff99ff);
                break;
            default:
                break;

        }

    }

    //seebar实现
    @Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {

    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {

    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {
        //改变画笔的粗细
        int progress = seekBar.getProgress();
        //paint.setStrokeWidth(progress);
        paint.setStrokeWidth(10 * progress /100f + 0.5f);

    }


    float startX = 0;
    float startY = 0;
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        //触摸ImageView的回调
        //触摸的时候绘制我们的图像,并且显示
        /*
            Touch时有三种情况:event.getAction()
            1.手指按下
            2.手指移动
            3.手指抬起
         */


        switch (event.getAction()){
            case MotionEvent.ACTION_DOWN://1次
                //1.手指按下
                startX = event.getX();//触摸的x坐标
                startY = event.getY();//触摸的y坐标

//                startX = event.getRawX();
//                startY = event.getRawY();


                break;
            case MotionEvent.ACTION_MOVE://0-多次
                //2.手指移动
                //绘制图像,并显示到ImageView上
                float stopX = event.getX();
                float stopY = event.getY();
//                float stopX = event.getRawX();
//                float stopY = event.getRawY();

                System.out.println("x :" + stopX + "  y : " + stopY);

                canvas.drawLine(startX,startY,stopX,stopY,paint);

                iv.setImageBitmap(bitmap);

                startX = stopX;
                startY = stopY;

                break;
            case MotionEvent.ACTION_UP://1次
                //3.手指抬起


                break;
            default:
                break;
        }



        return true;

    }


}


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