android 圖片疊加效果——兩種方法的簡介與內容，帶解決Immutable bitmap passed to Canvas constructor錯誤

時間 2019-11-18

標籤 android 圖片疊加效果兩種方法簡介內容解決 immutable bitmap passed canvas constructor 錯誤欄目 Android 简体版

原文原文鏈接

第一種是經過canvas畫出來的效果:java

[java] view plain copy print ?

public void first(View v) {



        // 防止出現Immutable bitmap passed to Canvas constructor錯誤

        Bitmap bitmap1 = BitmapFactory.decodeResource(getResources(),

                R.drawable.apple).copy(Bitmap.Config.ARGB_8888, true);

        Bitmap bitmap2 = ((BitmapDrawable) getResources().getDrawable(

                R.drawable.go)).getBitmap();



        Bitmap newBitmap = null;



        newBitmap = Bitmap.createBitmap(bitmap1);

        Canvas canvas = new Canvas(newBitmap);

        Paint paint = new Paint();



        int w = bitmap1.getWidth();

        int h = bitmap1.getHeight();



        int w_2 = bitmap2.getWidth();

        int h_2 = bitmap2.getHeight();



        paint.setColor(Color.GRAY);

        paint.setAlpha(125);

        canvas.drawRect(0, 0, bitmap1.getWidth(), bitmap1.getHeight(), paint);



        paint = new Paint();

        canvas.drawBitmap(bitmap2, Math.abs(w - w_2) / 2,

                Math.abs(h - h_2) / 2, paint);

        canvas.save(Canvas.ALL_SAVE_FLAG);

        // 存儲新合成的圖片

        canvas.restore();



        image.setImageBitmap(newBitmap);

    }
public void first(View v) {

        // 防止出現Immutable bitmap passed to Canvas constructor錯誤
        Bitmap bitmap1 = BitmapFactory.decodeResource(getResources(),
                R.drawable.apple).copy(Bitmap.Config.ARGB_8888, true);
        Bitmap bitmap2 = ((BitmapDrawable) getResources().getDrawable(
                R.drawable.go)).getBitmap();

        Bitmap newBitmap = null;

        newBitmap = Bitmap.createBitmap(bitmap1);
        Canvas canvas = new Canvas(newBitmap);
        Paint paint = new Paint();

        int w = bitmap1.getWidth();
        int h = bitmap1.getHeight();

        int w_2 = bitmap2.getWidth();
        int h_2 = bitmap2.getHeight();

        paint.setColor(Color.GRAY);
        paint.setAlpha(125);
        canvas.drawRect(0, 0, bitmap1.getWidth(), bitmap1.getHeight(), paint);

        paint = new Paint();
        canvas.drawBitmap(bitmap2, Math.abs(w - w_2) / 2,
                Math.abs(h - h_2) / 2, paint);
        canvas.save(Canvas.ALL_SAVE_FLAG);
        // 存儲新合成的圖片
        canvas.restore();

        image.setImageBitmap(newBitmap);
    }

Canvas canvas = new Canvas(newBitmap); 當以newBitmap建立Canvas時，因此操做都已經在該圖上實現了。android

該例子能夠想作是播放器開始播放的效果，計算好中間位置，先覆蓋一層透明灰色的正方形，而後在中間畫上本身播放的按鈕。canvas

第二種是使用系統的LayerDrawable類，該類主要用來控制多個圖片的結合：數組

[java] view plain copy print ?

public void second(View v) {
Bitmap bitmap1 = ((BitmapDrawable) getResources().getDrawable(
R.drawable.apple)).getBitmap();
Bitmap bitmap2 = ((BitmapDrawable) getResources().getDrawable(
R.drawable.go)).getBitmap();
Drawable[] array = new Drawable[2];
array[0] = new BitmapDrawable(bitmap1);
array[1] = new BitmapDrawable(bitmap2);
LayerDrawable la = new LayerDrawable(array);
// 其中第一個參數爲層的索引號，後面的四個參數分別爲left、top、right和bottom
la.setLayerInset(0, 0, 0, 0, 0);
la.setLayerInset(1, 20, 20, 20, 20);
image.setImageDrawable(la);
}

public void second(View v) {

        Bitmap bitmap1 = ((BitmapDrawable) getResources().getDrawable(
                R.drawable.apple)).getBitmap();
        Bitmap bitmap2 = ((BitmapDrawable) getResources().getDrawable(
                R.drawable.go)).getBitmap();

        Drawable[] array = new Drawable[2];
        array[0] = new BitmapDrawable(bitmap1);
        array[1] = new BitmapDrawable(bitmap2);
        LayerDrawable la = new LayerDrawable(array);
        // 其中第一個參數爲層的索引號，後面的四個參數分別爲left、top、right和bottom
        la.setLayerInset(0, 0, 0, 0, 0);
        la.setLayerInset(1, 20, 20, 20, 20);
        image.setImageDrawable(la);
    }

關聯數組array，控制每一層的位置app

裝載自：http://blog.csdn.net/gh102/article/details/6719624spa

注意：上面防止出現Immutable bitmap passed to Canvas constructor錯誤.net

緣由是若是不用copy的方法，直接引用會對資源文件進行修改，而android是不容許在代碼裏修改res文件裏的圖片rest