[移动开发]Android之 view提升： 九 使用Intent将图片分享到微信朋友圈

Android之 view提升： 九 使用Intent将图片分享到微信朋友圈

1. 知识点

1. 将图片压缩为JPG格式
2. 保存到存储卡上
3. 以流的形式传递图像资源

2. 代码

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

public class MainActivity extends AppCompatActivity {


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

        findViewById(R.id.btn1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.abc_2);
                String filePrefix = null;
                try {
                    filePrefix = saveImageToGallery(MainActivity.this, bitmap);
                } catch (IOException e) {
                    e.printStackTrace();
                }

                Intent myIntent = new Intent();
                ComponentName componentName = new ComponentName("com.tencent.mm",
                        "com.tencent.mm.ui.tools.ShareToTimeLineUI");
                myIntent.setComponent(componentName);
                myIntent.setAction(Intent.ACTION_SEND);
                myIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                myIntent.setType("image/jpg");
                Uri myUri = Uri.parse(filePrefix);
                myIntent.putExtra(Intent.EXTRA_STREAM, myUri);
                startActivity(myIntent);
            }
        });
    }

    private String saveImageToGallery(Context context, Bitmap bitmap) throws IOException {
        File mFile = new File(getCacheDir(), "luoGallery");
        if(!mFile.exists()) mFile.mkdir();
        String mFileName = System.currentTimeMillis() + ".jpg";
        String myNameTemp;
        File mNewFile = new File(mFile, mFileName);
        mNewFile.createNewFile();
        //图片压缩
        FileOutputStream outputStream = new FileOutputStream(mNewFile);
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);
        outputStream.flush();
        outputStream.close();
        //把图片放到系统图库中
        myNameTemp = MediaStore.Images.Media.insertImage(context.getContentResolver(),
                mNewFile.getAbsolutePath(), mFileName, null);
        //通知图库更新
        context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE,
                Uri.parse(getCacheDir().toString()+"/luoGallery")));
        return myNameTemp;
    }


}