android保存canvas 里面的图片,Android 如何将Canvas上绘制的内容保存成本地图片

效果如下图所示

保存在sd卡上的文件为

手机上显示效果为：

1》》在Manifest文件中增加相应权限

例如我的Manifest文件代码如下：

2》》详细代码如下

package com.demo.picturetest;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import android.app.Activity;

import android.graphics.Bitmap;

import android.graphics.Bitmap.Config;

import android.graphics.BitmapFactory;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.os.Bundle;

import android.os.Environment;

import android.util.Log;

import android.widget.ImageView;

public class MainActivity extends Activity {

private Bitmap mBitmap;

// 画布

private Canvas mCanvas;

// 画笔－－画图片

private Paint mPicturePaint = new Paint();

// 画笔－－写字

private Paint mTextPaint = new Paint();

// 画笔－－写运动数据

private Paint mDataPaint = new Paint();

private ImageView mImageView;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

drawBitmap();

init();

// 展示

mImageView.setImageBitmap(mBitmap);

}

private void init() {

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

}

/**

* 根据图片和文字生成图片

* */

private void drawBitmap() {

Bitmap bm_bg = BitmapFactory.decodeResource(getResources(),

R.drawable.dashboard_bg);

// 得到图片的宽、高

int width_bg = bm_bg.getWidth();

int height_bg = bm_bg.getHeight();

// 创建一个你需要尺寸的Bitmap

mBitmap = Bitmap.createBitmap(width_bg, height_bg, Config.ARGB_8888);

// 用这个Bitmap生成一个Canvas,然后canvas就会把内容绘制到上面这个bitmap中

mCanvas = new Canvas(mBitmap);

// 绘制背景图片

mCanvas.drawBitmap(bm_bg, 0.0f, 0.0f, mPicturePaint);

// 绘制图片

Bitmap bm_head = BitmapFactory.decodeResource(getResources(),

R.drawable.share_head_img);

// 得到图片的宽、高

int width_head = bm_head.getWidth();

int height_head = bm_head.getHeight();

// 绘制图片－－保证其在水平方向居中

mCanvas.drawBitmap(bm_head, (width_bg - width_head) / 2, 0.0f,

mPicturePaint);

// 绘制文字

mTextPaint.setColor(Color.WHITE);// 白色画笔

mTextPaint.setTextSize(80.0f);// 设置字体大小

// 绘制文字

mDataPaint.setColor(Color.RED);// 红色画笔

mDataPaint.setTextSize(120.0f);// 设置字体大小

String distanceTextString = "运动距离：";

String distanceDataString = String.valueOf(888);

String distanceScalString = "米";

float distanceTextString_width = mTextPaint.measureText(

distanceTextString, 0, distanceTextString.length());

float distanceDataString_width = mDataPaint.measureText(

distanceDataString, 0, distanceDataString.length());

float distanceScalString_width = mTextPaint.measureText(

distanceScalString, 0, distanceScalString.length());

float x = (width_bg - distanceTextString_width

- distanceDataString_width - distanceScalString_width) / 2;

mCanvas.drawText(distanceTextString, x, height_head, mTextPaint);// 绘制文字

mCanvas.drawText(distanceDataString, x + distanceTextString_width,

height_head, mDataPaint);// 绘制文字

mCanvas.drawText(distanceScalString, x + distanceTextString_width

+ distanceDataString_width, height_head, mTextPaint);// 绘制文字

// 保存绘图为本地图片

mCanvas.save(Canvas.ALL_SAVE_FLAG);

mCanvas.restore();

File file = new File(Environment.getExternalStorageDirectory()

.getPath() + "/share_pic.png");// 保存到sdcard根目录下，文件名为share_pic.png

Log.i("CXC", Environment.getExternalStorageDirectory().getPath());

FileOutputStream fos = null;

try {

fos = new FileOutputStream(file);

mBitmap.compress(Bitmap.CompressFormat.PNG, 50, fos);

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

try {

fos.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}