Android:将View的内容映射成Bitmap转图片导出

前段时间在网上看到这么个例子是将view映射到一个bitmap中，稍加改进可以用于一些截图工具或者截图软件（QQ截图之类），例子写的不够完善，不过很有些学习的意义内容大致如下：

在Android中自有获取view中的cache内容，然后将内容转换成bitmap，方法名是：getDrawingCache(),返回结果为Bitmap，但是刚开始使用的时候，得到的结果都是null，所以在一个论坛里查到了正确的使用方法.代码如下：

contentLayout.setDrawingCacheEnabled(true);

contentLayout.measure(

MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),

MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));

contentLayout.layout(0, 0, contentLayout.getMeasuredWidth(),

contentLayout.getMeasuredHeight());

contentLayout.buildDrawingCache();

Bitmap bitmap= contentLayout.getDrawingCache();

在使用的时候调用

Bitmap bitmap = view.getDrawingCache();

就可以得到图片的bitmap了。

为了测试这个功能，作者使用了两种方式来创建LinerLayout中的内容，一种是在xml文件中就将view的内容添加了，只需在代码中添加对应ImageView中的图片就行了；另一种是动态添加LinerLayout中的View。

setview的代码：

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.set_view);

contentLayout = (LinearLayout) findViewById(R.id.content);

imgSource1 = (ImageView) findViewById(R.id.imgSource1);

imgSource2 = (ImageView) findViewById(R.id.imgSource2);

imgCache = (ImageView) findViewById(R.id.imgCache);

imgSource1.setImageResource(R.drawable.source1);

imgSource2.setImageResource(R.drawable.source2);

contentLayout.setDrawingCacheEnabled(true);

contentLayout.measure(

MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),

MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));

contentLayout.layout(0, 0, contentLayout.getMeasuredWidth(),

contentLayout.getMeasuredHeight());

contentLayout.buildDrawingCache();

Bitmap bitmap= contentLayout.getDrawingCache();

if(bitmap!=null){

imgCache.setImageBitmap(bitmap);

}else{

Log.i("CACHE_BITMAP", "DrawingCache=null");

}

}

第二种方法代码：

private void addRelativeLayout() {

// TODO Auto-generated method stub

RelativeLayout.LayoutParams layoutpare = new RelativeLayout.LayoutParams(

LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);

RelativeLayout relativeLayout = new RelativeLayout(this);

relativeLayout.setLayoutParams(layoutpare);

ImageView imgView1 = new ImageView(this);

ImageView imgView2 = new ImageView(this);

imgView1.setImageResource(R.drawable.source1);

imgView2.setImageResource(R.drawable.source2);

RelativeLayout.LayoutParams img1 = new RelativeLayout.LayoutParams(38,

38);

img1.addRule(RelativeLayout.ALIGN_PARENT_LEFT, RelativeLayout.TRUE);

RelativeLayout.LayoutParams img2 = new RelativeLayout.LayoutParams(38,

38);

img2.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, RelativeLayout.TRUE);

relativeLayout.addView(imgView1, img1);

relativeLayout.addView(imgView2, img2);

addViewContent.addView(relativeLayout);

}

/**

* 添加图片源

*/

private void addImgSource() {

ImageView imgView1 = new ImageView(this);

ImageView imgView2 = new ImageView(this);

imgView1.setImageResource(R.drawable.source1);

imgView2.setImageResource(R.drawable.source2);

addViewContent.addView(imgView1, new LayoutParams(

LinearLayout.LayoutParams.WRAP_CONTENT,

LinearLayout.LayoutParams.WRAP_CONTENT));

addViewContent.addView(imgView2, new LayoutParams(

LinearLayout.LayoutParams.WRAP_CONTENT,

LinearLayout.LayoutParams.WRAP_CONTENT));

}