二维码

首先导入依赖架包libzxing

package com.example.erweima;

import android.content.Intent;
import android.graphics.Bitmap;
import android.support.v4.os.EnvironmentCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;

import com.xys.libzxing.zxing.activity.CaptureActivity;
import com.xys.libzxing.zxing.encoding.EncodingUtils;

public class MainActivity extends AppCompatActivity {

    private TextView tv;
    private Intent intent;
    private EditText et;
    private ImageView im;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //找到控件
        tv = findViewById(R.id.tv);
        et = findViewById(R.id.et);
        im = findViewById(R.id.im);
        //创建意图
        intent = new Intent(MainActivity.this, CaptureActivity.class);

    }
    //点击事件
    public void buu(View view){
        //跳转
        startActivity(intent);
    }
    //点击事件
    public void bu(View view){
        //获取TextView的值
        String str = et.getText().toString();
        //把值生成一个图片二维码
        Bitmap qrCode = EncodingUtils.createQRCode(str, 100, 100, null);
        //把生成的图片二维码赋值到ImageView上
        im.setImageBitmap(qrCode);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode==RESULT_OK){
            Bundle extras = data.getExtras();
            String result = extras.getString("result");
            tv.setText(result);
        }
    }
}