Android View转换成图片保存

package zhangphil.viewtoimage;

import java.io.File;
import java.io.FileOutputStream;

import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;

/**
 * 把Android的一个View转换成图片保存
 * 
 * */

public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		final TextView tv = (TextView) findViewById(R.id.textView);
		tv.setBackgroundColor(Color.GREEN);
		// tv.setDrawingCacheEnabled(true);

		final Runnable runnable = new Runnable() {
			@Override
			public void run() {
				viewSaveToImage(tv);
			}
		};

		Button button = (Button) findViewById(R.id.button);
		button.setOnClickListener(new View.OnClickListener() {

			@Override
			public void onClick(View v) {
				new Handler().post(runnable);
			}
		});

	}

	public void viewSaveToImage(View view) {
		view.setDrawingCacheEnabled(true);
		view.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);
		view.setDrawingCacheBackgroundColor(Color.WHITE);

		// 把一个View转换成图片
		Bitmap cachebmp = loadBitmapFromView(view);

		// 添加水印
		Bitmap bitmap = Bitmap.createBitmap(createWatermarkBitmap(cachebmp,
				"@ Zhang Phil"));

		FileOutputStream fos;
		try {
			// 判断手机设备是否有SD卡
			boolean isHasSDCard = Environment.getExternalStorageState().equals(
					android.os.Environment.MEDIA_MOUNTED);
			if (isHasSDCard) {
				// SD卡根目录
				File sdRoot = Environment.getExternalStorageDirectory();
				File file = new File(sdRoot, "test.PNG");
				fos = new FileOutputStream(file);
			} else
				throw new Exception("创建文件失败!");

			bitmap.compress(Bitmap.CompressFormat.PNG, 90, fos);

			fos.flush();
			fos.close();

		} catch (Exception e) {
			e.printStackTrace();
		}

		view.destroyDrawingCache();
	}

	private Bitmap loadBitmapFromView(View v) {
		int w = v.getWidth();
		int h = v.getHeight();

		Bitmap bmp = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
		Canvas c = new Canvas(bmp);

		c.drawColor(Color.WHITE);
		/** 如果不设置canvas画布为白色，则生成透明 */

		v.layout(0, 0, w, h);
		v.draw(c);

		return bmp;
	}

	// 为图片target添加水印
	private Bitmap createWatermarkBitmap(Bitmap target, String str) {
		int w = target.getWidth();
		int h = target.getHeight();

		Bitmap bmp = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
		Canvas canvas = new Canvas(bmp);

		Paint p = new Paint();

		// 水印的颜色
		p.setColor(Color.RED);

		// 水印的字体大小
		p.setTextSize(16);

		p.setAntiAlias(true);// 去锯齿

		canvas.drawBitmap(target, 0, 0, p);

		// 在中间位置开始添加水印
		canvas.drawText(str, w / 2, h / 2, p);

		canvas.save(Canvas.ALL_SAVE_FLAG);
		canvas.restore();

		return bmp;
	}
}