Log.i(“MyPaintToolsActivity”,imageview.getWidth()+" "+imageview.getHeight());
Point point = new Point();
getWindowManager().getDefaultDisplay().getSize(point);
Log.i(“MyPaintToolsActivity”,point.x+" "+point.y);
bitmap = Bitmap.createBitmap(888,1200,Bitmap.Config.ARGB_8888);
canvas = new Canvas(bitmap);
canvas.drawColor(Color.argb(100,0,0,0));
paint = new Paint();
paint.setStrokeWidth(5);
paint.setAntiAlias(true);
paint.setColor(Color.RED);
canvas.drawBitmap(bitmap,new Matrix(),paint);
imageview.setImageBitmap(bitmap);
注册触摸监听事件,获取鼠标按下时的坐标和鼠标移动后的坐标。在开始和结束之间画一条直线并更新画布图片
imageview.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
switch(event.getAction()){
case MotionEvent.ACTION_DOWN:
Log.i(“MyPaintToolsActivity”,“ACTION_DOWN”);
startX = (int) (event.getX()/1.4);
startY = (int) (event.getY()/1.4);
break;
case MotionEvent.ACTION_MOVE:
Log.i(“MyPaintToolsActivity”,“ACTION_MOVE”);
endX = (int) (event.getX()/1.4);
endY = (int) (event.getY()/1.4);
canvas.drawLine(startX,startY,endX,endY,paint);
startX = (int) (event.getX()/1.4);
startY = (int) (event.getY()/1.4);
imageview.setImageBitmap(bitmap);
break;
case MotionEvent.ACTION_UP:
Log.i(“MyPaintToolsActivity”,“ACTION_UP”);
break;
}
imageview.invalidate();
return true;
}
});
清屏的话就一行代码 ,剩下的是重新生成一块画布
Button btn_clear = findViewById(R.id.btn_clear);
btn_clear.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
canvas.drawColor(0,PorterDuff.Mode.CLEAR);
bitmap = Bitmap.createBitmap(888,1200,Bitmap.Config.ARGB_8888);
canvas = new Canvas(bitmap);
canvas.drawColor(Color.argb(100,0,0,0));
paint = new Paint();
paint.setStrokeWidth(5);
paint.setAntiAlias(true);
paint.setColor(Color.RED);
canvas.drawBitmap(bitmap,new Matrix(),paint);
imageview.setImageBitmap(bitmap);
}
});
呃,这里会把画布擦掉…也就是擦成白色…
// 擦除
Button btn_eraser = findViewById(R.id.btn_eraser);
btn_eraser.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
paint.setColor(Color.rgb(250,250,250));
paint.setStrokeWidth(30);
}
});
}
}
最后看看页面布局
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android=“http://schemas.android.com/apk/res/android”
xmlns:app=“http://schemas.android.com/apk/res-auto”
xmlns:tools=“http://schemas.android.com/tools”
android:layout_width=“match_parent”
android:layout_height=“match_parent”
android:orientation=“vertical”
android:id="@+id/ll_layout">
<ImageView
android:id="@+id/imageview"
android:layout_width=“match_parent”
android:layout_height=“match_parent”
android:layout_weight=“1” />
<RadioGroup
android:background="#747373"
android:layout_width=“match_parent”
android:orientation=“horizontal”
android:id="@+id/rg_color"
android:layout_height=“wrap_content”>
<RadioButton
android:id="@+id/rb_red"
android:layout_width=“wrap_content”
android:layout_height=“43dp”
android:layout_weight=“1”
android:text=“红色”
android:textColor="#FF0000"
android:textSize=“18sp” />
<RadioButton
android:id="@+id/rb_green"
android:layout_width=“wrap_content”
android:layout_height=“30dp”
android:layout_weight=“1”
android:text=“黑色”
android:textColor="#000000"
android:textSize=“18sp” />
<RadioButton
android:id="@+id/rb_blue"
资源分享
- 最新大厂面试专题
这个题库内容是比较多的,除了一些流行的热门技术面试题,如Kotlin,数据库,Java虚拟机面试题,数组,Framework ,混合跨平台开发,等
- 对应导图的Android高级工程师进阶系统学习视频
最近热门的,NDK,热修复,MVVM,源码等一系列系统学习视频都有!
droid:id="@+id/rb_blue"
资源分享
- 最新大厂面试专题
这个题库内容是比较多的,除了一些流行的热门技术面试题,如Kotlin,数据库,Java虚拟机面试题,数组,Framework ,混合跨平台开发,等
[外链图片转存中…(img-5JEhaWbm-1643868385771)]
- 对应导图的Android高级工程师进阶系统学习视频
最近热门的,NDK,热修复,MVVM,源码等一系列系统学习视频都有!
[外链图片转存中…(img-t6tFe9vC-1643868385772)]