技術標籤：Androidandroid

自定義View畫圓,畫扇形

建立一個類繼承自View

public class lhjclass extends View {
    public lhjclass(Context context) {
        super(context);
    }

    public lhjclass(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public lhjclass(Context context,
 
 @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        //建立畫筆
        Paint paint = new Paint();
        //設定畫筆顏色
 

        paint.setColor(Color.WHITE);
        //設定畫筆線條
        paint.setStrokeWidth(20);
        //設定樣式STROKE(空心),FILL(實心)
        paint.setStyle(Paint.Style.STROKE);
        //畫扇形(true,false表示扇形兩邊的線是否顯示)
        canvas.drawArc(320,180,570,430,90,270,false,paint);

        //同心圓
       /*  paint.setColor(Color.WHITE);
           canvas.drawCircle(450,300,180,paint);//畫圓
           paint.setColor(Color.GREEN);
           canvas.drawCircle(450,300,150,paint);*/
 

    }
}

佈局直接使用

<?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:orientation="vertical"
    android:layout_height="match_parent"
    tools:context=".MainActivity">


        <com.example.a1225.lhjclass
            android:layout_width="wrap_content"
            android:layout_height="300dp"
            android:background="#1AFF00"
            ></com.example.a1225.lhjclass>

</LinearLayout>

效果圖