本文实例为大家分享了Android画画板展示的具体代码，供大家参考，具体内容如下
main.xml布局
<RelativeLayout 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" tools:context="com.example.demo.MainActivity"> <ImageView android:id="@+id/iv" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/bg" /> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:layout_alignParentBottom="true" > <Button android:id="@+id/red" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="红色" android:onClick="onplay" /> <Button android:id="@+id/green" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="绿色" android:onClick="onplay" /> <Button android:id="@+id/root" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="刷子" android:onClick="onplay" /> <Button android:id="@+id/save" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="保存" android:onClick="onplay" /> <Button android:id="@+id/finish" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="涂漆" android:onClick="onplay" /> </LinearLayout></RelativeLayout>
main布局
/*画板canvas 画板paint 手势识别器整体思路:因为我是图片是作画,实际是对图片进行修改,起到画图的效果1.原图,白纸,画笔,画板2.根据手势识别进行作画 */public class MainActivity extends AppCompatActivity {
private Bitmap bitmap;
private Canvas canvas;
private ImageView iv;
private int startx;
private int starty;
private Paint paint;
private Bitmap bmSrc;
@Override protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//加载原图 bmSrc = BitmapFactory.decodeResource(getResources(), R.drawable.bg);
//创建白纸,宽,高,图片的参数 bitmap = Bitmap.createBitmap(bmSrc.getWidth(), bmSrc.getHeight(), bmSrc.getConfig());
//创建画板,参数是白纸对象 canvas = new Canvas(bitmap);
//创建画笔 paint = new Paint();
//在纸上作画 iv=(ImageView)findViewById(R.id.iv);
canvas.drawBitmap(bmSrc,new Matrix(), paint);
//-----------------手势识别器和画笔结合的知识------------------- //给控件设置手势适配器,可以得到用户在这个控件上所做的手势 iv.setOnTouchListener(new View.OnTouchListener() {
//当用户手在这个控件时,指的就是用户的手对控件滑动,按下,松开的三种场景,自动回调 @Override public boolean onTouch(View view, MotionEvent motionEvent) {
switch (motionEvent.getAction()){
case MotionEvent.ACTION_DOWN://按下时回调一次 //获取用户手指按下时的坐标 startx = (int) motionEvent.getX();
starty = (int) motionEvent.getY();
break;
case MotionEvent.ACTION_MOVE://手指滑动时,不停地调用 int newx = (int) motionEvent.getX();
int newy = (int) motionEvent.getY();
//在背景图画线 canvas.drawLine(startx,starty,newx,newy, paint);
startx=newx;
starty=newy;
iv.setImageBitmap(bitmap);
break;
case MotionEvent.ACTION_UP://松开时回调一次 break;
}
//事情分发机制 //true:iv处理该触摸事件 //false:iv不处理该触摸事件,事件传递给上一级 return true;
}
}
);
}
public void onplay(View view){
switch (view.getId()){
case R.id.red: paint.setColor(Color.RED);
break;
case R.id.green: paint.setColor(Color.GREEN);
break;
case R.id.root: paint.setStrokeWidth(5);
break;
case R.id.save: if(SaveViewUtil.saveScreen(iv)){
Toast.makeText(this, "截图成功", Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(this, "截图失败，请检查sdcard是否可用", Toast.LENGTH_SHORT).show();
}
break;
//涂漆 case R.id.finish: canvas.drawRect(new Rect(0,0,width,height), paint);
break;
}
}
}
这是一个把画的图存储SD卡的工具类
public class SaveViewUtil {
private static final File rootDir = new File(Environment.getExternalStorageDirectory()+File.separator);
/**保存截图的方法*/ public static boolean saveScreen(View view){
//判断sdcard是否可用 if(!Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())){
return false;
}
if(!rootDir.exists()){
rootDir.mkdir();
}
view.setDrawingCacheEnabled(true);
view.buildDrawingCache();
Bitmap bitmap = view.getDrawingCache();
try {
bitmap.compress(CompressFormat.JPEG, 100, new FileOutputStream(new File(rootDir,System.currentTimeMillis()+".jpg")));
return true;
}
catch (FileNotFoundException e) {
e.printStackTrace();
return false;
}
finally{
view.setDrawingCacheEnabled(false);
bitmap = null;
}
}
}
<!-- 往SDCard写入数据权限 --><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。
