Android學習筆記進階16之BitmapShader

<1>簡介

具體的看一下博文：Android學習筆記進階15之Shader渲染

 

public   BitmapShader(Bitmap bitmap,Shader.TileMode tileX,Shader.TileMode tileY)

調用這個方法來產生一個畫有一個位圖的渲染器（Shader）。

bitmap   在渲染器內使用的位圖

tileX      The tiling mode for x to draw the bitmap in.   在位圖上X方向花磚模式

tileY     The tiling mode for y to draw the bitmap in.    在位圖上Y方向花磚模式

 

TileMode：（一共有三種）

CLAMP  ：如果渲染器超出原始邊界范圍，會復制范圍內邊緣染色。

REPEAT ：橫向和縱向的重復渲染器圖片，平鋪。

MIRROR ：橫向和縱向的重復渲染器圖片，這個和REPEAT 重復方式不一樣，他是以鏡像方式平鋪。

還是不太明白？那看一下效果圖吧！

                                       REPEAT                                                                                                                       MIRROR

<2>具體實現

 

package xiaosi.BitmapShader; import android.app.Activity; import android.os.Bundle; public class BitmapShaderActivity extends Activity { /** Called when the activity is first created. */ private BitmapShaders bitmapShaders = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); bitmapShaders = new BitmapShaders(this); setContentView(bitmapShaders); } }

 

BitmapShaders.java

package xiaosi.BitmapShader; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapShader; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Shader; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.ShapeDrawable; import android.graphics.drawable.shapes.OvalShape; import android.view.View; public class BitmapShaders extends View { private BitmapShader bitmapShader = null; private Bitmap bitmap = null; private Paint paint = null; private ShapeDrawable shapeDrawable = null; private int BitmapWidth = 0; private int BitmapHeight = 0; public BitmapShaders(Context context) { super(context); //得到圖像 bitmap = ((BitmapDrawable) getResources().getDrawable(R.drawable.h)).getBitmap(); BitmapWidth = bitmap.getWidth(); BitmapHeight = bitmap.getHeight(); //構造渲染器BitmapShader bitmapShader = new BitmapShader(bitmap,Shader.TileMode.MIRROR,Shader.TileMode.REPEAT); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); //將圖片裁剪為橢圓形 //構建ShapeDrawable對象並定義形狀為橢圓 shapeDrawable = new ShapeDrawable(new OvalShape()); //得到畫筆並設置渲染器 shapeDrawable.getPaint().setShader(bitmapShader); //設置顯示區域 shapeDrawable.setBounds(20, 20,BitmapWidth-60,BitmapHeight-60); //繪制shapeDrawable shapeDrawable.draw(canvas); } }