https://blog.csdn.net/dianluanbi7490/article/details/102017020
三张图片叠加
package com.zmlxj.customcompass; import androidx.appcompat.app.AppCompatActivity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.Drawable; import android.graphics.drawable.LayerDrawable; import android.os.Bundle; import android.util.Log; import android.widget.ImageView; public class Main2Activity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main2); ImageView image=findViewById(R.id.iv_image); /* // 防止出现Immutable bitmap passed to Canvas constructor错误 Bitmap bitmap1 = BitmapFactory.decodeResource(getResources(), R.drawable.compass_bottom).copy(Bitmap.Config.ARGB_8888, true); Bitmap bitmap2 = ((BitmapDrawable) getResources().getDrawable( R.drawable.compass_char)).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(); // 存储新合成的图片 canvas.restore(); image.setImageBitmap(newBitmap);*/ Bitmap bitmap1 = ((BitmapDrawable) getResources().getDrawable( R.drawable.compass_bottom)).getBitmap(); Bitmap bitmap2 = ((BitmapDrawable) getResources().getDrawable( R.drawable.compass_char)).getBitmap(); Bitmap bitmap3 = ((BitmapDrawable) getResources().getDrawable( R.drawable.compass_pointer)).getBitmap(); Drawable[] array = new Drawable[3]; array[0] = new BitmapDrawable(bitmap1); array[1] = new BitmapDrawable(bitmap2); array[2] = new BitmapDrawable(bitmap3); LayerDrawable la = new LayerDrawable(array); // 其中第一个参数为层的索引号，后面的四个参数分别为left、top、right和bottom la.setLayerInset(0, 0, 0, 0, 0); la.setLayerInset(1, 20, 20, 20, 20); int[] all= getImageWidthHeight(); Log.i("获取的值",all[0]+"_"+all[1]); la.setLayerInset(2, 40, (all[1]/8), 40, 40); image.setImageDrawable(la); } public int[] getImageWidthHeight(){ BitmapFactory.Options options = new BitmapFactory.Options(); /** * 最关键在此，把options.inJustDecodeBounds = true; * 这里再decodeFile()，返回的bitmap为空，但此时调用options.outHeight时，已经包含了图片的高了 */ options.inJustDecodeBounds = true; // Bitmap bitmap = BitmapFactory.decodeFile(this.getResources()., options); // 此时返回的bitmap为null BitmapFactory.decodeResource(getResources(),R.drawable.compass_bottom,options); /** *options.outHeight为原始图片的高 */ return new int[]{options.outWidth,options.outHeight}; } }实现效果
