Android屏幕截图，view转bitmap

开发中经常会用到屏幕的截图，其实我们常用的一种方法是将view转换成bitmap，这样可以截取你想要的那一部分的图片了，实现代码如下：

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;
    }
}

可以直接使用