import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.Path;
import android.graphics.Shader;
import android.graphics.LinearGradient;
/**
* 主程序中继承自Android.view.View的 MyView类，重写 MyView的onDraw()方法，
* 一开始就会运行绘制的工作，在onDraw()中以Paint将几何图形绘制在Canvas上， 以 paint.setColor() 改变图形颜色、以
* paint.setStyle()的设置来控制画出的的 图形是空心还是实心。程序的最后一段，就是直接在Canvas写上文字，随着Paint对
* 象里的属性设置，也会有不同的外观模式。
*/
public class GraphicesActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
/** 设置ContentView为自定义的MyVieW */
MyView myView = new MyView(this);
setContentView(myView);
}
/** 自定义继承View 的MyView */
private class MyView extends View {
public MyView(Context context) {
super(context);
}
/** 重写onDraw() */
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
/** 设置背景为白色 */
canvas.drawColor(Color.WHITE);
Paint paint = new Paint();
/** 去锯齿 */
paint.setAntiAlias(true);
/** 设置paint的颜色 */
paint.setColor(Color.RED);
/** 设置paint的 style 为STROKE：空心 */
paint.setStyle(Paint.Style.STROKE);
/** 设置paint的外框宽度 */
paint.setStrokeWidth(3);
/** 画一个空心圆形 */
canvas.drawCircle(40, 40, 30, paint);
/** 画一个空心正方形 */
canvas.drawRect(10, 90, 70, 150, paint);
/** 画一个空心长方形 */
canvas.drawRect(10, 170, 70, 200, paint);
/** 画一个空心椭圆形 */
canvas.drawOval(new RectF(10, 220, 70, 250), paint);
/** 画一个空心三角形 */
Path path = new Path();
path.moveTo(10, 330);
path.lineTo(70, 330);
path.lineTo(40, 270);
path.close();
canvas.drawPath(path, paint);
/** 画一个空心梯形 */
Path path1 = new Path();
path1.moveTo(10, 410);
path1.lineTo(70, 410);
path1.lineTo(55, 350);
path1.lineTo(25, 350);
path1.close();
canvas.drawPath(path1, paint);
/** 设置paint的颜色 */
paint.setColor(Color.BLUE);
/** 设置paint 的style为 FILL：实心 */
paint.setStyle(Paint.Style.FILL);
/** 画一个实心圆 */
canvas.drawCircle(120, 40, 30, paint);
/** 画一个实心正方形 */
canvas.drawRect(90, 90, 150, 150, paint);
/** 画一个实心长方形 */
canvas.drawRect(90, 170, 150, 200, paint);
/** 画一个实心椭圆 */
RectF re2 = new RectF(90, 220, 150, 250);
canvas.drawOval(re2, paint);
/** 画一个实心三角形 */
Path path2 = new Path();
path2.moveTo(90, 330);
path2.lineTo(150, 330);
path2.lineTo(120, 270);
path2.close();
canvas.drawPath(path2, paint);
/** 画一个实心梯形 */
Path path3 = new Path();
path3.moveTo(90, 410);
path3.lineTo(150, 410);
path3.lineTo(135, 350);
path3.lineTo(105, 350);
path3.close();
canvas.drawPath(path3, paint);
/** 设置渐变色 */
Shader mShader = new LinearGradient(0, 0, 100, 100, new int[] {
Color.RED, Color.GREEN, Color.BLUE, Color.YELLOW }, null,
Shader.TileMode.REPEAT);
/**
* Shader.TileMode三种模式 REPEAT:沿着渐变方向循环重复
* CLAMP:如果在预先定义的范围外画的话，就重复边界的颜色 MIRROR:与REPEAT一样都是循环重复，但这个会对称重复
*/
paint.setShader(mShader);// 用Shader中定义定义的颜色来话
/** 画一个渐变色圆 */
canvas.drawCircle(200, 40, 30, paint);
/** 画一个渐变色正方形 */
canvas.drawRect(170, 90, 230, 150, paint);
/** 画一个渐变色长方形 */
canvas.drawRect(170, 170, 230, 200, paint);
/** 画一个渐变色椭圆 */
RectF re3 = new RectF(170, 220, 230, 250);
canvas.drawOval(re3, paint);
/** 画一个渐变色三角形 */
Path path4 = new Path();
path4.moveTo(170, 330);
path4.lineTo(230, 330);
path4.lineTo(200, 270);
path4.close();
canvas.drawPath(path4, paint);
/** 画一个渐变色梯形 */
Path path5 = new Path();
path5.moveTo(170, 410);
path5.lineTo(230, 410);
path5.lineTo(215, 350);
path5.lineTo(185, 350);
path5.close();
canvas.drawPath(path5, paint);
/** 写字 */
paint.setTextSize(24);
canvas.drawText("圆形", 240, 50, paint);
canvas.drawText("正方形", 240, 120, paint);
canvas.drawText("长方形", 240, 190, paint);
canvas.drawText("椭圆形", 240, 250, paint);
canvas.drawText("三角形", 240, 320, paint);
canvas.drawText("梯形", 240, 390, paint);
}
}
}
