使用View繪畫簡單的圖形

看別人的博文，自己也最好有個筆記，以後可以解決很多事情，幫助自己，也方便大家。

1.自定義一個View

package com.ekin.android.viewtest;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.view.View;
public class MyView extends View {
    private Paint paint ;
    public MyView(Context context) {
        super(context);
        paint = new Paint();
        paint.setAntiAlias(true);//設置畫筆無鋸齒(如果不設置可以看到效果很差)
        this.setKeepScreenOn(true);
        paint.setColor(Color.RED);
    }
    @Override
    public void onDraw(Canvas canvas) {
        canvas.drawColor(Color.WHITE);//設置刷屏顏色
        Rect rect = new Rect(30,30,50,50); //這裏最後兩個參數不是寬高、而是矩形右下角的座標
        canvas.drawRect(rect, paint);
        RectF rectF = new RectF(70f,30f,90f,90f);//RectF 只是矩形 float形式 只是跟Rect精確度不一樣
        canvas.drawArc(rectF, 0, 360, true, paint);
        canvas.drawCircle(150, 30, 20, paint);//這也是畫圓 第三個參數爲半徑
        float[] points =new float[]{200f,10f,200f,40f,300f,30f,400f,70f};
        canvas.drawLines(points, paint);
//      canvas.drawLines(points, 1, 4, paint);//選取特定點數組中兩點來畫出一條直線
        canvas.drawText("Ekin
View", 230, 30, paint);
    }
}

2.將自己的View顯示在指定的Activity上面

view pla

package com.ekin.android.viewtest;
import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.view.WindowManager;
public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
//隱去電池等圖標和一切修飾部分（狀態欄部分）
        this.getWindow().setFlags(
WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
 
this.requestWindowFeature(Window.FEATURE_NO_TITLE);  // 隱去標題欄（程序的名字）
        setContentView(new MyView(this));
    }
}