android应用程序使用按钮保存和加载值(android application save and load value with button)
java
我编写了一个BMI计算器，现在我想用一个按钮保存并加载重量和高度值，有人知道怎么做吗？
package com.example.test.bmicalculator; import android.app.Activity; import android.content.Context; import android.content.SharedPreferences; import android.os.Bundle; import android.preference.PreferenceManager; import android.view.View; import android.widget.EditText; import android.widget.TextView; public class MyActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_my); } public void calculateClickHandler(View view) { // make sure we handle the click of the calculator button if (view.getId() == R.id.calculateButton) { // get the references to the widgets EditText weightText = (EditText)findViewById(R.id.weightText); EditText heightText = (EditText)findViewById(R.id.heightText); TextView resultText = (TextView)findViewById(R.id.resultLabel); // get the users values from the widget references float weight = Float.parseFloat(weightText.getText().toString()); float height = Float.parseFloat(heightText.getText().toString()); // calculate the bmi value float bmiValue = calculateBMI(weight, height); // interpret the meaning of the bmi value String bmiInterpretation = interpretBMI(bmiValue); // now set the value in the result text resultText.setText(bmiValue + "-" + bmiInterpretation); } } // the formula to calculate the BMI index // check for http://en.wikipedia.org/wiki/Body_mass_index private float calculateBMI (float weight, float height) { return (float) (weight * 4.88 / (height * height)); } // interpret what BMI means private String interpretBMI(float bmiValue) { if (bmiValue < 16) { return "Severely underweight"; } else if (bmiValue < 18.5) { return "Underweight"; } else if (bmiValue < 25) { return "Normal"; } else if (bmiValue < 30) { return "Overweight"; } else { return "Obese"; } } public void SaveClickHandler(View view) { // here I want to Save the weight and the height value } public void LoadClickHandler(View view) { // here I want to Load the weight and the height value } }I have programmed a BMI Calculator and now I want to save and load the weight and height value with a button, does anyone know how to do this?
package com.example.test.bmicalculator; import android.app.Activity; import android.content.Context; import android.content.SharedPreferences; import android.os.Bundle; import android.preference.PreferenceManager; import android.view.View; import android.widget.EditText; import android.widget.TextView; public class MyActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_my); } public void calculateClickHandler(View view) { // make sure we handle the click of the calculator button if (view.getId() == R.id.calculateButton) { // get the references to the widgets EditText weightText = (EditText)findViewById(R.id.weightText); EditText heightText = (EditText)findViewById(R.id.heightText); TextView resultText = (TextView)findViewById(R.id.resultLabel); // get the users values from the widget references float weight = Float.parseFloat(weightText.getText().toString()); float height = Float.parseFloat(heightText.getText().toString()); // calculate the bmi value float bmiValue = calculateBMI(weight, height); // interpret the meaning of the bmi value String bmiInterpretation = interpretBMI(bmiValue); // now set the value in the result text resultText.setText(bmiValue + "-" + bmiInterpretation); } } // the formula to calculate the BMI index // check for http://en.wikipedia.org/wiki/Body_mass_index private float calculateBMI (float weight, float height) { return (float) (weight * 4.88 / (height * height)); } // interpret what BMI means private String interpretBMI(float bmiValue) { if (bmiValue < 16) { return "Severely underweight"; } else if (bmiValue < 18.5) { return "Underweight"; } else if (bmiValue < 25) { return "Normal"; } else if (bmiValue < 30) { return "Overweight"; } else { return "Obese"; } } public void SaveClickHandler(View view) { // here I want to Save the weight and the height value } public void LoadClickHandler(View view) { // here I want to Load the weight and the height value } }最满意答案
您可以使用SharedPreferences以下操作：
public void SaveClickHandler(View view) { SharedPreferences prefs = getSharedPreferences(Context.MODE_PRIVATE); SharedPreferences.Editor editor = prefs.edit(); editor.putFloat("height", height); editor.putFloat("weight", weight); editor.commit(); }当你想获得这个值时，你会这样做：
public void LoadClickHandler(View view) { float height = prefs.getFloat("height", 0.0f); //Default value (0.0f) float weight= prefs.getFloat("weight", 0.0f); //Default value (0.0f) //Do more stuff }编辑
将这些height和weight作为全局变量，如下所示：
浮子高度，重量;
然后在你的onCreate()你这样做：
weight = Float.parseFloat(weightText.getText().toString()); height = Float.parseFloat(heightText.getText().toString());并在LoadClickHandler()添加此代码
public void LoadClickHandler(View view) { float heightSaved = prefs.getFloat("height", 0.0f); //Default value (0.0f) float weightSaved= prefs.getFloat("weight", 0.0f); //Default value (0.0f) //Do more stuff }改变这个：
SharedPreferences prefs = getSharedPreferences(Context.MODE_PRIVATE);对此：
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(view.getContext());最终代码
public class MyActivity extends Activity { float weight, height; SharedPreferences prefs; EditText weightText, heightText; TextView resultText; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_my); prefs = PreferenceManager.getDefaultSharedPreferences(this); // get the references to the widgets weightText = (EditText)findViewById(R.id.weightText); heightText = (EditText)findViewById(R.id.heightText); resultText = (TextView)findViewById(R.id.resultLabel); } public void calculateClickHandler(View view) { // make sure we handle the click of the calculator button if (view.getId() == R.id.calculateButton) { // get the users values from the widget references weight = Float.parseFloat(weightText.getText().toString()); height = Float.parseFloat(heightText.getText().toString()); // calculate the bmi value float bmiValue = calculateBMI(weight, height); // interpret the meaning of the bmi value String bmiInterpretation = interpretBMI(bmiValue); // now set the value in the result text resultText.setText(bmiValue + "-" + bmiInterpretation); } } // the formula to calculate the BMI index // check for http://en.wikipedia.org/wiki/Body_mass_index private float calculateBMI (float weight, float height) { return (float) (weight * 4.88 / (height * height)); } // interpret what BMI means private String interpretBMI(float bmiValue) { if (bmiValue < 16) { return "Severely underweight"; } else if (bmiValue < 18.5) { return "Underweight"; } else if (bmiValue < 25) { return "Normal"; } else if (bmiValue < 30) { return "Overweight"; } else { return "Obese"; } } public void SaveClickHandler(View view) { // here I want to Save the weight and the height value prefs = PreferenceManager.getDefaultSharedPreferences(view.getContext()); SharedPreferences.Editor editor = prefs.edit(); editor.putFloat("height", height); editor.putFloat("weight", weight); editor.apply(); } public void LoadClickHandler(View view) { // here I want to Load the weight and the height value height = prefs.getFloat("height", 0.0f); //Default value (0.0f) weight= prefs.getFloat("weight", 0.0f); //Default value (0.0f) heightText.setText(String.valueOf(height)); weightText.setText(String.valueOf(weight)); }You can do it with SharedPreferences as follows :
public void SaveClickHandler(View view) { SharedPreferences prefs = getSharedPreferences(Context.MODE_PRIVATE); SharedPreferences.Editor editor = prefs.edit(); editor.putFloat("height", height); editor.putFloat("weight", weight); editor.commit(); }And when you want to get this value you do this :
public void LoadClickHandler(View view) { float height = prefs.getFloat("height", 0.0f); //Default value (0.0f) float weight= prefs.getFloat("weight", 0.0f); //Default value (0.0f) //Do more stuff }Edit
Make those height and weight as a global variables as follows :
float height, weight;
Then in your onCreate() you do this :
weight = Float.parseFloat(weightText.getText().toString()); height = Float.parseFloat(heightText.getText().toString());And add this code in your LoadClickHandler()
public void LoadClickHandler(View view) { float heightSaved = prefs.getFloat("height", 0.0f); //Default value (0.0f) float weightSaved= prefs.getFloat("weight", 0.0f); //Default value (0.0f) //Do more stuff }Change this :
SharedPreferences prefs = getSharedPreferences(Context.MODE_PRIVATE);to this :
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(view.getContext());FINAL CODE
public class MyActivity extends Activity { float weight, height; SharedPreferences prefs; EditText weightText, heightText; TextView resultText; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_my); prefs = PreferenceManager.getDefaultSharedPreferences(this); // get the references to the widgets weightText = (EditText)findViewById(R.id.weightText); heightText = (EditText)findViewById(R.id.heightText); resultText = (TextView)findViewById(R.id.resultLabel); } public void calculateClickHandler(View view) { // make sure we handle the click of the calculator button if (view.getId() == R.id.calculateButton) { // get the users values from the widget references weight = Float.parseFloat(weightText.getText().toString()); height = Float.parseFloat(heightText.getText().toString()); // calculate the bmi value float bmiValue = calculateBMI(weight, height); // interpret the meaning of the bmi value String bmiInterpretation = interpretBMI(bmiValue); // now set the value in the result text resultText.setText(bmiValue + "-" + bmiInterpretation); } } // the formula to calculate the BMI index // check for http://en.wikipedia.org/wiki/Body_mass_index private float calculateBMI (float weight, float height) { return (float) (weight * 4.88 / (height * height)); } // interpret what BMI means private String interpretBMI(float bmiValue) { if (bmiValue < 16) { return "Severely underweight"; } else if (bmiValue < 18.5) { return "Underweight"; } else if (bmiValue < 25) { return "Normal"; } else if (bmiValue < 30) { return "Overweight"; } else { return "Obese"; } } public void SaveClickHandler(View view) { // here I want to Save the weight and the height value prefs = PreferenceManager.getDefaultSharedPreferences(view.getContext()); SharedPreferences.Editor editor = prefs.edit(); editor.putFloat("height", height); editor.putFloat("weight", weight); editor.apply(); } public void LoadClickHandler(View view) { // here I want to Load the weight and the height value height = prefs.getFloat("height", 0.0f); //Default value (0.0f) weight= prefs.getFloat("weight", 0.0f); //Default value (0.0f) heightText.setText(String.valueOf(height)); weightText.setText(String.valueOf(weight)); }更多推荐
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