Android Implementation of Drawing Board Case
- 2021-11-01 04:37:52
- OfStack
In this paper, we share the specific code of Android drawing board for your reference, the specific contents are as follows
① Prepare 1 layout file
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main"
android:layout_width="match_parent" android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:orientation="vertical"
tools:context="com.example.it.MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:text=" Modify color "
android:onClick="color"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:text=" Thickness +1"
android:onClick="size"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:text=" Save Picture "
android:onClick="save"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
<ImageView
android:id="@+id/iv_bg"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
② Core code
package com.example.it;
import android.content.Intent;
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.net.Uri;
import android.os.Environment;
import android.os.SystemClock;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
public class MainActivity extends AppCompatActivity {
private final String TAG = getClass().getSimpleName();
private ImageView iv_show;
private Bitmap copyBm;
private float x;
private float y;
private Paint paint;
private int paintsize = 1;
private FileOutputStream fos;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Initialize control
iv_show = (ImageView) findViewById(R.id.iv_bg);
// Create 1 A blank bitmap
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.bg);
copyBm = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());
// Create a canvas
final Canvas canvas = new Canvas(copyBm);
// Drawing pictures with canvas
paint = new Paint();
canvas.drawBitmap(bitmap,new Matrix(), paint);
iv_show.setImageBitmap(copyBm);
// Set listening events for brush movement on screen
iv_show.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
// Gets the type of the current event
int action = event.getAction();
switch (action){
case MotionEvent.ACTION_DOWN:
// If the finger is pressed, , Record 1 Position of lower finger
x = event.getX();
y = event.getY();
Log.e(TAG,x+"******"+y);
break;
case MotionEvent.ACTION_MOVE:
// If the finger is moving
float x1 = event.getX();
float y1 = event.getY();
canvas.drawLine(x,y,x1,y1, paint);
x = x1;
y = y1;
Log.e(TAG,x1+"**********"+y1);
break;
case MotionEvent.ACTION_UP:
break;
}
iv_show.setImageBitmap(copyBm);
return true;
}
});
}
// Modify color
public void color(View view) {
paint.setColor(Color.RED);
}
// Modify line thickness
public void size(View view) {
paintsize+=1;
paint.setStrokeWidth(paintsize);
}
// Save Picture
public void save(View view) {
// Set the location where the picture is saved
File file = new File(Environment.getExternalStorageDirectory(), SystemClock.currentThreadTimeMillis()+".png");
try {
fos = new FileOutputStream(file);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
// Set the quality of parameter saving
copyBm.compress(Bitmap.CompressFormat.PNG,100,fos);
// Definition 1 Individual intention , Send a broadcast to tell the system to scan the file at the specified location
Intent intent = new Intent();
intent.setAction(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
intent.setData(Uri.fromFile(file));
sendBroadcast(intent);
}
}
③ Authority information
<
uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/
>