1.先上没有填充效果的代码和效果图
myview负责画出一个红色的手机屏幕大小的矩形，至于填充什么，自己加。
public class MyView extends View
{
// 声明画笔
public Paint paint;
public MyView(Context context) {
super(context);
paint = new Paint();
paint.setColor(Color.RED);
}
public MyView(Context context, AttributeSet attrs) {
super(context, attrs);
paint = new Paint();
paint.setColor(Color.RED);
}
@Override
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
// 使用指定Paint对象画矩形
Log.i("mydate" , " " + getWidth() + " " + getHeight());
canvas.drawRect(0, 0, getWidth(), getHeight(), paint);
}
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.example.liuyan.testshader.MyView
android:id="@+id/myviw"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public void onClick(View v) {
}
}
2.加上填充效果 BitmapShader
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
MyView myView;
private Matrix matrix = new Matrix();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
WindowManager windowManager = getWindowManager();
Display display = windowManager.getDefaultDisplay();
DisplayMetrics metrics = new DisplayMetrics();
display.getMetrics(metrics);
float screenwidth = metrics.widthPixels;
float screenhight = metrics.heightPixels;
myView = (MyView) findViewById(R.id.myviw);
Bitmap bm = BitmapFactory.decodeResource(getResources() , R.drawable.ly);
int width = bm.getWidth();
int height = bm.getHeight();
float scale = screenwidth/2/width; //显示图片的缩放比例
float scale2 = screenhight/2/height;
matrix.setScale(scale , scale2); //将显示的图片缩放到屏幕大小
Bitmap bj = Bitmap.createBitmap(bm , 0 ,0 , width , height , matrix , true);
Shader shader0 = new BitmapShader(bj , Shader.TileMode.REPEAT , Shader.TileMode.MIRROR);//x方向重复，y方向镜像
//********************************************
myView.paint.setShader(shader0); //将填充效果传入
myView.invalidate(); //重新绘制
}
@Override
public void onClick(View v) {
}
}
3.加上填充效果LinearGradient
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
MyView myView;
private Matrix matrix = new Matrix();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myView = (MyView) findViewById(R.id.myviw);;
/*WindowManager windowManager = getWindowManager();
Display display = windowManager.getDefaultDisplay();
DisplayMetrics metrics = new DisplayMetrics();
display.getMetrics(metrics);
float screenwidth = metrics.widthPixels;
float screenhight = metrics.heightPixels;
Bitmap bm = BitmapFactory.decodeResource(getResources() , R.drawable.ly);
int width = bm.getWidth();
int height = bm.getHeight();
float scale = screenwidth/2/width; //显示图片的缩放比例
float scale2 = screenhight/2/height;
matrix.setScale(scale , scale2); //将显示的图片缩放到屏幕大小
Bitmap bj = Bitmap.createBitmap(bm , 0 ,0 , width , height , matrix , true);
Shader shader0 = new BitmapShader(bj , Shader.TileMode.REPEAT , Shader.TileMode.MIRROR);
myView.paint.setShader(shader0); //将填充效果传入
myView.invalidate(); //重新绘制*/
//************************************************
int[] colors = new int[]{Color.RED , Color.GREEN , Color.BLUE};
Shader shader1 = new LinearGradient(0 , 0 , 50 , 50 , colors , null , Shader.TileMode.REPEAT);//
myView.paint.setShader(shader1); //将填充效果传入
myView.invalidate(); //重新绘制
}
@Override
public void onClick(View v) {
}
}
4.加上填充效果SweepGradient
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
MyView myView;
private Matrix matrix = new Matrix();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myView = (MyView) findViewById(R.id.myviw);;
/*WindowManager windowManager = getWindowManager();
Display display = windowManager.getDefaultDisplay();
DisplayMetrics metrics = new DisplayMetrics();
display.getMetrics(metrics);
float screenwidth = metrics.widthPixels;
float screenhight = metrics.heightPixels;
Bitmap bm = BitmapFactory.decodeResource(getResources() , R.drawable.ly);
int width = bm.getWidth();
int height = bm.getHeight();
float scale = screenwidth/2/width; //显示图片的缩放比例
float scale2 = screenhight/2/height;
matrix.setScale(scale , scale2); //将显示的图片缩放到屏幕大小
Bitmap bj = Bitmap.createBitmap(bm , 0 ,0 , width , height , matrix , true);
Shader shader0 = new BitmapShader(bj , Shader.TileMode.REPEAT , Shader.TileMode.MIRROR);
myView.paint.setShader(shader0); //将填充效果传入
myView.invalidate(); //重新绘制*/
/*int[] colors = new int[]{Color.RED , Color.GREEN , Color.BLUE};
Shader shader1 = new LinearGradient(0 , 0 , 50 , 50 , colors , null , Shader.TileMode.REPEAT);//
myView.paint.setShader(shader1); //将填充效果传入
myView.invalidate(); //重新绘制*/
//*****************************************************
int[] colors = new int[]{Color.RED , Color.GREEN , Color.BLUE};
Shader shader2 = new SweepGradient(160 , 160 , colors , null); //渲染中心x,y坐标，渲染颜色数组，相对位置的颜色数组可为null
myView.paint.setShader(shader2);
myView.invalidate();
}
@Override
public void onClick(View v) {
}
}
5.加上填充效果RadialGradient
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
MyView myView;
private Matrix matrix = new Matrix();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myView = (MyView) findViewById(R.id.myviw);;
/*WindowManager windowManager = getWindowManager();
Display display = windowManager.getDefaultDisplay();
DisplayMetrics metrics = new DisplayMetrics();
display.getMetrics(metrics);
float screenwidth = metrics.widthPixels;
float screenhight = metrics.heightPixels;
Bitmap bm = BitmapFactory.decodeResource(getResources() , R.drawable.ly);
int width = bm.getWidth();
int height = bm.getHeight();
float scale = screenwidth/2/width; //显示图片的缩放比例
float scale2 = screenhight/2/height;
matrix.setScale(scale , scale2); //将显示的图片缩放到屏幕大小
Bitmap bj = Bitmap.createBitmap(bm , 0 ,0 , width , height , matrix , true);
Shader shader0 = new BitmapShader(bj , Shader.TileMode.REPEAT , Shader.TileMode.MIRROR);
myView.paint.setShader(shader0); //将填充效果传入
myView.invalidate(); //重新绘制*/
/*int[] colors = new int[]{Color.RED , Color.GREEN , Color.BLUE};
Shader shader1 = new LinearGradient(0 , 0 , 50 , 50 , colors , null , Shader.TileMode.REPEAT);//
myView.paint.setShader(shader1); //将填充效果传入
myView.invalidate(); //重新绘制*/
/*int[] colors = new int[]{Color.RED , Color.GREEN , Color.BLUE};
Shader shader2 = new SweepGradient(160 , 160 , colors , null); //渲染中心x,y坐标，渲染颜色数组，相对位置的颜色数组可为null
myView.paint.setShader(shader2);
myView.invalidate();*/
//*****************************************************
int[] colors = new int[]{Color.RED , Color.GREEN , Color.BLUE};
Shader shader3 = new RadialGradient(100 , 100 , 80 , colors , null , Shader.TileMode.REPEAT);
myView.paint.setShader(shader3);
myView.invalidate();
}
@Override
public void onClick(View v) {
}
}
6.加上填充效果ComposeShader
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
MyView myView;
private Matrix matrix = new Matrix();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myView = (MyView) findViewById(R.id.myviw);;
WindowManager windowManager = getWindowManager();
Display display = windowManager.getDefaultDisplay();
DisplayMetrics metrics = new DisplayMetrics();
display.getMetrics(metrics);
float screenwidth = metrics.widthPixels;
float screenhight = metrics.heightPixels;
Bitmap bm = BitmapFactory.decodeResource(getResources() , R.drawable.ly);
int width = bm.getWidth();
int height = bm.getHeight();
float scale = screenwidth/2/width; //显示图片的缩放比例
float scale2 = screenhight/2/height;
matrix.setScale(scale , scale2); //将显示的图片缩放到屏幕大小
Bitmap bj = Bitmap.createBitmap(bm , 0 ,0 , width , height , matrix , true);
Shader shader0 = new BitmapShader(bj , Shader.TileMode.REPEAT , Shader.TileMode.MIRROR);
/*myView.paint.setShader(shader0); //将填充效果传入
myView.invalidate(); //重新绘制*/
int[] colors = new int[]{Color.RED , Color.GREEN , Color.BLUE};
Shader shader1 = new LinearGradient(0 , 0 , 50 , 50 , colors , null , Shader.TileMode.REPEAT);//
/*myView.paint.setShader(shader1); //将填充效果传入
myView.invalidate(); //重新绘制*/
//int[] colors = new int[]{Color.RED , Color.GREEN , Color.BLUE};
Shader shader2 = new SweepGradient(160 , 160 , colors , null); //渲染中心x,y坐标，渲染颜色数组，相对位置的颜色数组可为null
/*myView.paint.setShader(shader2);
myView.invalidate();*/
//int[] colors = new int[]{Color.RED , Color.GREEN , Color.BLUE};
Shader shader3 = new RadialGradient(100 , 100 , 80 , colors , null , Shader.TileMode.REPEAT);
/*myView.paint.setShader(shader3);
myView.invalidate();*/
//组合效果
Shader shader4 = new ComposeShader(shader0 , shader3 , PorterDuff.Mode.DARKEN);
myView.paint.setShader(shader4); //组合效果填充
myView.invalidate();
}
@Override
public void onClick(View v) {
}
}
简单介绍到此为止
至于
PorterDuff.Mode.DARKEN
可以到该网址查看 https://www.jianshu.com/p/d11892bbe055