畫布上的可繪製圖像

Question

如何在畫布上獲取圖像以便在該圖像上繪製？

Answer 1

試試這個

Bitmap mBitmap = Bitmap.createScaledBitmap(Bitmap src, int dstWidth, int dstHeight, boolean filter); 

protected void onDraw(Canvas canvas) { 
      canvas.drawColor(0xFFAAAAAA); 
      canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint); 

     } 

Answer 2

您需要加載圖像作爲位圖：

Resources res = getResources(); 
Bitmap bitmap = BitmapFactory.decodeResource(res, R.drawable.your_image); 

然後使位圖可變的，並創建了它在畫布：

Canvas canvas = new Canvas(bitmap.copy(Bitmap.Config.ARGB_8888, true)); 

然後你可以在畫布上畫畫。

Answer 3

package com.android.jigsawtest; 

import android.content.Context; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.view.SurfaceHolder; 
import android.view.SurfaceView; 

public class SurafaceClass extends SurfaceView implements 
     SurfaceHolder.Callback { 
    Bitmap mBitmap; 
Paint paint =new Paint(); 
    public SurafaceClass(Context context) { 
     super(context); 
     mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.icon); 
     // TODO Auto-generated constructor stub 
    } 

    @Override 
    public void surfaceChanged(SurfaceHolder holder, int format, int width, 
      int height) { 
     // TODO Auto-generated method stub 

    } 

    @Override 
    public void surfaceCreated(SurfaceHolder holder) { 
     // TODO Auto-generated method stub 

    } 

    @Override 
    public void surfaceDestroyed(SurfaceHolder holder) { 
     // TODO Auto-generated method stub 

    } 

    @Override 
    protected void onDraw(Canvas canvas) { 
     canvas.drawColor(Color.BLACK); 
     canvas.drawBitmap(mBitmap, 0, 0, paint); 

    } 

} 

Answer 4

我不知道，你必須將圖像作爲位圖加載爲你的代碼（http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.1_r2/android/widget/ProgressBar.java#ProgressBar.onDraw%28android.graphics.Canvas%29） 使用Drawable.draw(Canvas c)。

Answer 5

的好方法繪製在畫布上繪製對象不是自己的解碼，但它留給系統可以這樣做：

Drawable d = getResources().getDrawable(R.drawable.foobar); 
d.setBounds(left, top, right, bottom); 
d.draw(canvas); 

這將有各類可繪製的，不僅是位圖工作。而且這也意味着如果只改變大小，您可以再次使用相同的drawable。

Answer 6

也可以使用這種方式。將你的大drawble適合改變你的畫布：

Resources res = getResources(); 
Bitmap bitmap = BitmapFactory.decodeResource(res, yourDrawable); 
yourCanvas.drawBitmap(bitmap, 0, 0, yourPaint); 

Answer 7

Drawable d = ContextCompat.getDrawable(context, R.drawable.***) 
d.setBounds(left, top, right, bottom); 
d.draw(canvas);