自由手記

為了實現在TextView中顯示圖片，有時對圖片的寬度與高度有限制的话，可以對圖片進行放大與缩小操作！

main.xml
   <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
<TextView android:text="TextView01" android:id="@+id/TextView01" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
<TextView android:text="TextView02" android:id="@+id/TextView02" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
</LinearLayout>

GridView.java
   
package a.gridview;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.widget.TextView;

public class GridView extends Activity {
        
        private TextView text;
        private TextView text1;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        text = (TextView) findViewById(R.id.TextView01);
        Drawable draw = this.getResources().getDrawable(R.drawable.srvmng);   
        text.setCompoundDrawablesWithIntrinsicBounds(null, draw, null,null);
        text.setText("應用");
        
        text1 = (TextView) findViewById(R.id.TextView02);
        Drawable draw1 = this.getResources().getDrawable(R.drawable.srvmng);  
        int w = draw1.getIntrinsicWidth();
        int h = draw1.getIntrinsicHeight();
        Rect rect = draw1.getBounds();
        text1.setCompoundDrawablesWithIntrinsicBounds(null, zoomDrawable(draw1,32,32), null,null);
        text1.setText("設定");
    }
    
    static Drawable zoomDrawable(Drawable drawable, int w, int h)
    {
              int width = drawable.getIntrinsicWidth();
              int height= drawable.getIntrinsicHeight();
              Bitmap oldbmp = drawableToBitmap(drawable); // drawable轉換成bitmap
              Matrix matrix = new Matrix();   // 建立操作圖片用的Matrix對象
              float scaleWidth = ((float)w / width);   // 計算缩放比例
              float scaleHeight = ((float)h / height);
              matrix.postScale(scaleWidth, scaleHeight);         // 設定缩放比例
              Bitmap newbmp = Bitmap.createBitmap(oldbmp, 0, 0, width, height, matrix, true);       // 建立新的bitmap，其内容是對原bitmap的缩放后的圖
              return new BitmapDrawable(newbmp);       // 把bitmap轉換成drawable並返回
    }

    static Bitmap drawableToBitmap(Drawable drawable) // drawable 轉換成bitmap
    {
              int width = drawable.getIntrinsicWidth();   // 取drawable的長寬
              int height = drawable.getIntrinsicHeight();
              Bitmap.Config config = drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888:Bitmap.Config.RGB_565;         // 取drawable的颜色格式
              Bitmap bitmap = Bitmap.createBitmap(width, height, config);     // 建立对应bitmap
              Canvas canvas = new Canvas(bitmap);         // 建立對應bitmap的畫布
              drawable.setBounds(0, 0, width, height);
              drawable.draw(canvas);      // 把drawable内容畫到畫布中
              return bitmap;
    }

}