Android 取得手機內的圖片, Intent, Intent.ACTION_GET_CONTENT, Uri, Log, ContentResolver, Bitmap, startActivityForResult

getpicture.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="取得圖片"
        android:id="@+id/myButton" />

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/myImage" />
</LinearLayout>

GetPictureDemo.java

package com.example.administrator.test;

import android.app.Activity;
import android.content.ContentResolver;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

import java.io.FileNotFoundException;

/**
 * Created by Administrator on 2014/10/10.
 */
public class GetPictureDemo extends Activity {
    private Button mButton;
    private ImageView mImageView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.getpicture);

        mButton = (Button) findViewById(R.id.myButton);
        mImageView = (ImageView) findViewById(R.id.myImage);

        mButton.setOnClickListener(new Button.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent();
                intent.setType("image/*");      //開啟Pictures畫面Type設定為image
                intent.setAction(Intent.ACTION_GET_CONTENT);    //使用Intent.ACTION_GET_CONTENT
                startActivityForResult(intent, 1);      //取得相片後, 返回
            }
        });
    }

    /* 取得相片後返回的監聽 */
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        /* 當使用者按下確定後 */
        if (resultCode == RESULT_OK) {
            Uri uri = data.getData();                       //取得圖檔的路徑
            Log.e("uri", uri.toString());                   //寫log
            ContentResolver cr = this.getContentResolver(); //抽象資料的接口

            try {
                /* 由抽象資料接口轉換圖檔路徑為Bitmap */
                Bitmap bitmap = BitmapFactory.decodeStream(cr.openInputStream(uri));

                mImageView.setImageBitmap(bitmap);

            } catch (FileNotFoundException e) {
                Log.e("Exception", e.getMessage(), e);
            }
        }

        super.onActivityResult(requestCode, resultCode, data);
    }
}

note.text

 呼叫android取得手機內圖片很簡單，只要用Intent.ACTION_GET_CONTENT

重點在於取得圖檔後面的處理，因為取得只是取出該圖檔的存放路徑，所以必須經由

抽象接口ContentResolver再把該圖檔轉換為Bitmap，轉換為Bitmap主要是用來餵給imageView


下面是幾種常用可以設定imageView內圖片的型式
          imageView.setImageBitmap(bitmap) //bitmap圖檔型式
	  imageView.setImageDrawable(drawable) //drawable圖檔型式
	  imageView.setImageResource(resId) //存在應用程式中res/drawable內的圖片
	  imageView.setImageURI(uri)//網路圖片路徑