android简单图形示例 android简单图形|Android

【android简单图形示例】android.graphics.Canvas可用于在android中绘制图形。它提供了绘制椭圆，矩形，图片，文本，线条等的方法。
android.graphics.Paint类与画布一起使用以绘制对象。它包含颜色和样式的信息。
在此示例中，我们将在android中显示2D图形。
activity_main.xml

< RelativeLayout xmlns:androclass="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" 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" tools:context=".MainActivity" >< TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/hello_world" />< /RelativeLayout>

活动类

package com.example.simplegraphics; import android.os.Bundle; import android.app.Activity; import android.view.Menu; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.view.View; public class MainActivity extends Activity { DemoView demoview; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); demoview = new DemoView(this); setContentView(demoview); } private class DemoView extends View{ public DemoView(Context context){ super(context); }@Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); // custom drawing code here Paint paint = new Paint(); paint.setStyle(Paint.Style.FILL); // make the entire canvas white paint.setColor(Color.WHITE); canvas.drawPaint(paint); // draw blue circle with anti aliasing turned off paint.setAntiAlias(false); paint.setColor(Color.BLUE); canvas.drawCircle(20, 20, 15, paint); // draw green circle with anti aliasing turned on paint.setAntiAlias(true); paint.setColor(Color.GREEN); canvas.drawCircle(60, 20, 15, paint); // draw red rectangle with anti aliasing turned off paint.setAntiAlias(false); paint.setColor(Color.RED); canvas.drawRect(100, 5, 200, 30, paint); // draw the rotated text canvas.rotate(-45); paint.setStyle(Paint.Style.FILL); canvas.drawText("Graphics Rotation", 40, 180, paint); //undo the rotate canvas.restore(); } } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } }

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