个人整理思路：
1.获取相册中图片，得到图片的路径
2.获取保存图片设置的边框的宽高，
与原有宽高计算出缩放比例----第一次采样只读取图片，不加载到内存
3.将图片加载到内存中-----第二次采样
4.得到bitmap，放入到指定边框
基类：
package com.example.twosampling;
import android.os.Bundle;
import android.os.PersistableBundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
//抽象的
public abstract class BaseActivity extends AppCompatActivity {
@Override
public void onCreate( @Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//设置内容视图
setContentView(getLayoutResId());
//初始化view
initView();
//初始化数据
initData();
}
//初始化内容视图
protected abstract int getLayoutResId();
//初始化视图
protected abstract void initView();
// 初始化数据
protected abstract void initData();
}
MainActivity
package com.example.twosampling;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.net.Uri;
import android.provider.MediaStore;
import android.support.annotation.Nullable;
import android.support.v4.content.CursorLoader;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
public class MainActivity extends BaseActivity {
//定义变量
private Button choose,produce;
private EditText edit_wide,edit_high;
private ImageView image;
private Uri uri;
@Override
protected int getLayoutResId() {
return R.layout.activity_main;
}
@Override //视图
protected void initView() {
//获取资源ID
choose=findViewById(R.id.choose);
produce=findViewById(R.id.produce);
edit_wide=findViewById(R.id.edit_wide);
edit_high=findViewById(R.id.edit_high);
image=findViewById(R.id.image);
}
@Override //数据加载
protected void initData() {
//选择按钮点击获取图片
choose.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//打开系统相册
Intent it=new Intent(Intent.ACTION_PICK);
//设置类型
it.setType("image/*");
//回传值
startActivityForResult(it,100);
}
});
//二次采样
produce.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//得到输入框的值
String w = edit_wide.getText().toString();
String h = edit_high.getText().toString();
//得到真实的路径
String url = getUrl(uri);
NetUtile.getInstance().getBitmap2(url, Integer.parseInt(w), Integer.parseInt(h), new NetUtile.CallBack<Bitmap>() {
@Override
public void onsuccess(Bitmap bitmap) {
image.setImageBitmap(bitmap);
}
});
}
});
}
//获取文件对应的真实路径----固定格式
private String getUrl(Uri contentUri ){
String[] pr = {MediaStore.Images.Media.DATA};
CursorLoader loader = new CursorLoader(this, contentUri, pr, null, null, null);
Cursor cursor = loader.loadInBackground();
int index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(index);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode==100&&resultCode==RESULT_OK){
uri = data.getData();//得到图片的uri------二次采样用到图片的路径
}
}
}
工具类
package com.example.twosampling;
import android.annotation.SuppressLint;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
public class NetUtile {
private static NetUtile instance;
private NetUtile(){
}
public static NetUtile getInstance(){
if (instance==null){
instance=new NetUtile();
}
return instance;
}
//图片的二次采样 //要加载的图片路径 控件中图片的宽、高
public Bitmap getBitmap(String filePath,int destWidth,int destHeight){
//第一次************
BitmapFactory.Options options = new BitmapFactory.Options();
//指定只解析bitmap的宽高信息,只读取图片，不加载到内存
options.inJustDecodeBounds=true;
BitmapFactory.decodeFile(filePath,options);
//获得原图的宽和高
int outWidth = options.outWidth;
int outHeight = options.outHeight;
//定义缩放比例---2的n次方
options.inSampleSize=Math.max(outWidth/destWidth,outHeight/destHeight);
//第二次************ 图片加载到内存
options.inJustDecodeBounds=false;
Bitmap bitmap = BitmapFactory.decodeFile(filePath, options);
return bitmap;
}
//定义接口
public interface CallBack<Bitmap>{
void onsuccess(Bitmap bitmap);
}
//子线程
@SuppressLint("StaticFieldLeak")
public void getBitmap2(String filepath, final int destwidth, final int destheight, final CallBack callBack){ //返回值Bitmap
new AsyncTask<String, Void, Bitmap>() {
@Override
protected Bitmap doInBackground(String... strings) {
Bitmap bitmap = getBitmap(strings[0], destwidth, destheight);
return bitmap;
}
@Override
protected void onPostExecute(Bitmap bitmap) {
callBack.onsuccess(bitmap);
}
}.execute(filepath);//根据图片的路径
}
}
xml布局：
<?xml version="1.0" encoding="utf-8"?><android.support.constraint.ConstraintLayout xmlns:android=“http://schemas.android.com/apk/res/android”
xmlns:app=“http://schemas.android.com/apk/res-auto”
xmlns:tools=“http://schemas.android.com/tools”
android:layout_width=“match_parent”
android:layout_height=“match_parent”
tools:context=".MainActivity">
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<TextView
android:id="@+id/wide"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="宽"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toBottomOf="@id/choose"
android:padding="40dp"
android:textSize="20dp"
/>
<EditText
android:id="@+id/edit_wide"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintTop_toBottomOf="@id/choose"
app:layout_constraintLeft_toRightOf="@id/wide"
android:padding="20dp"
/>
<TextView
android:id="@+id/high"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="高"
android:textSize="20dp"
app:layout_constraintLeft_toRightOf="@id/edit_wide"
app:layout_constraintTop_toBottomOf="@id/choose"
android:padding="40dp"
/>
<EditText
android:id="@+id/edit_high"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="20dp"
app:layout_constraintLeft_toRightOf="@id/high"
app:layout_constraintTop_toBottomOf="@id/choose"
/>
<Button
android:id="@+id/produce"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="生成"
app:layout_constraintTop_toBottomOf="@id/edit_wide"
android:layout_margin="20dp"
/>
<ImageView
android:id="@+id/image"
android:layout_width="150dp"
android:layout_height="150dp"
app:layout_constraintTop_toBottomOf="@id/produce"
android:layout_margin="40dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
/>
</android.support.constraint.ConstraintLayout>