Android实战简易教程-第二十八枪（Uri转String型实例）

接上一篇文章。我们能够轻易的获取所选图片的uri，那么我们考虑怎样将获取的uri转换成String型的地址呢？

接下来我们通过实例来研究。布局文件和上篇（二十七枪）一致，我们就不再列出，直接看MainActivity.java:

package com.example.userphoto;

import java.io.File;

import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
import cn.bmob.v3.Bmob;
import cn.bmob.v3.datatype.BmobFile;
import cn.bmob.v3.listener.UploadFileListener;

public class MainActivity extends Activity implements OnClickListener {
	private static final int IMAGE_REQUEST_CODE = 0;
	private static final int CAMERA_REQUEST_CODE = 1;
	private static final int RESIZE_REQUEST_CODE = 2;

	private static final String IMAGE_FILE_NAME = "header.jpg";

	private ImageView mImageHeader;

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

		Bmob.initialize(this, "8f3ffb2658d8a3366a70a0b0ca0b71b2");//初始化Bmob
		setupViews();
	}

	private void setupViews() {
		mImageHeader = (ImageView) findViewById(R.id.image_header);
		final Button selectBtn1 = (Button) findViewById(R.id.btn_selectimage);
		final Button selectBtn2 = (Button) findViewById(R.id.btn_takephoto);
		selectBtn1.setOnClickListener(this);
		selectBtn2.setOnClickListener(this);
	}

	@Override
	public void onClick(View v) {
		switch (v.getId()) {
		case R.id.btn_selectimage:
			Intent galleryIntent = new Intent(Intent.ACTION_GET_CONTENT);
			galleryIntent.addCategory(Intent.CATEGORY_OPENABLE);
			galleryIntent.setType("image/*");//图片
			startActivityForResult(galleryIntent, IMAGE_REQUEST_CODE);
			break;
		case R.id.btn_takephoto:
			if (isSdcardExisting()) {
				Intent cameraIntent = new Intent(
						"android.media.action.IMAGE_CAPTURE");//拍照
				cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, getImageUri());
				cameraIntent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 0);
				startActivityForResult(cameraIntent, CAMERA_REQUEST_CODE);
			} else {
				Toast.makeText(v.getContext(), "请插入sd卡", Toast.LENGTH_LONG)
						.show();
			}
			break;
		}
	}

	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		if (resultCode != RESULT_OK) {
			return;
		} else {
			switch (requestCode) {
			case IMAGE_REQUEST_CODE:
				Uri originalUri=data.getData();//获取图片uri
				resizeImage(originalUri);
				//以下方法将获取的uri转为String类型哦！
				String []imgs={MediaStore.Images.Media.DATA};//将图片URI转换成存储路径
				Cursor cursor=this.managedQuery(originalUri, imgs, null, null, null);
				int index=cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
				cursor.moveToFirst();
				String img_url=cursor.getString(index);
				showToast(img_url);
				break;
			case CAMERA_REQUEST_CODE:
				if (isSdcardExisting()) {
					resizeImage(getImageUri());

					/*// 上传图片
					String imgpath = getImageUri();
					final BmobFile icon = new BmobFile(new File(imgpath));
					icon.upload(this, new UploadFileListener() {

						@Override
						public void onSuccess() {
							// TODO Auto-generated method stub
							Person person = new Person();
							person.setIcon(icon);
							person.save(MainActivity.this);
							showToast("图片上传成功");
						}

						@Override
						public void onProgress(Integer arg0) {
							// TODO Auto-generated method stub

						}

						@Override
						public void onFailure(int arg0, String arg1) {
							// TODO Auto-generated method stub
							showToast("图片上传失败："+arg1);
						}
					});*/
				} else {
					Toast.makeText(MainActivity.this, "未找到存储卡，无法存储照片！

",
							Toast.LENGTH_LONG).show();
				}
				break;

			case RESIZE_REQUEST_CODE:
				if (data != null) {
					showResizeImage(data);
				}
				break;
			}
		}

		super.onActivityResult(requestCode, resultCode, data);
	}
	private void showToast(String msg){
		Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
	}

	private boolean isSdcardExisting() {//推断SD卡是否存在
		final String state = Environment.getExternalStorageState();
		if (state.equals(Environment.MEDIA_MOUNTED)) {
			return true;
		} else {
			return false;
		}
	}

	public void resizeImage(Uri uri) {//重塑图片大小
		Intent intent = new Intent("com.android.camera.action.CROP");
		intent.setDataAndType(uri, "image/*");
		intent.putExtra("crop", "true");//能够裁剪
		intent.putExtra("aspectX", 1);
		intent.putExtra("aspectY", 1);
		intent.putExtra("outputX", 150);
		intent.putExtra("outputY", 150);
		intent.putExtra("return-data", true);
		startActivityForResult(intent, RESIZE_REQUEST_CODE);
	}

	private void showResizeImage(Intent data) {//显示图片
		Bundle extras = data.getExtras();
		if (extras != null) {
			Bitmap photo = extras.getParcelable("data");
			Drawable drawable = new BitmapDrawable(photo);
			mImageHeader.setImageDrawable(drawable);
		}
	}

	private Uri getImageUri() {//获取路径
		return Uri.fromFile(new File(Environment.getExternalStorageDirectory(),
				IMAGE_FILE_NAME));
	}
}

将方法单列出来即：

                                Uri originalUri=data.getData();//获取图片uri
				resizeImage(originalUri);
				//以下方法将获取的uri转为String类型哦！
				String []imgs={MediaStore.Images.Media.DATA};//将图片URI转换成存储路径
				Cursor cursor=this.managedQuery(originalUri, imgs, null, null, null);
				int index=cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
				cursor.moveToFirst();
				String img_url=cursor.getString(index);
				showToast(img_url);

执行实例会出现例如以下错误：

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不懂英文的也大概能看懂，提示权限不足，我们加入例如以下权限：

执行实例，顺利通过：

Toast中显示出了图片的路径，话说获取这路径有什么用？请看下篇文章（二十九枪）。

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