Question

我试图在项目的这一部分中传递变量“stockSymbol”...

ticker.setText("Stock Ticker is: " + stockSymbol);

与我项目的这一部分相同......

final String yqlURL = yahooURLFirst + stockSymbol + yahooURLSecond;

这是完整的代码......

String stockSymbol = "";

...

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_stock_info);

    stock = (EditText) findViewById(R.id.stock);
    ticker = (TextView) findViewById(R.id.ticker);
    btnquote = (Button) findViewById(R.id.btnquote);
    btnquote.setOnClickListener(new OnClickListener() {

        public void onClick(View v) {
            // get the name from edittext and storing into string variable
            String stockSymbol = stock.getText().toString();

           // binding name to the textview
           ticker.setText("Stock Ticker is: " + stockSymbol);
       }
    });

    // Initialize TextViews
    companyNameTextView = (TextView) findViewById(R.id.companyNameTextView);
    yearLowTextView = (TextView) findViewById(R.id.yearLowTextView);
    yearHighTextView = (TextView) findViewById(R.id.yearHighTextView);
    daysLowTextView = (TextView) findViewById(R.id.daysLowTextView);
    daysHighTextView = (TextView) findViewById(R.id.daysHighTextView);
    lastTradePriceOnlyTextView = (TextView) findViewById(R.id.lastTradePriceOnlyTextView);
    changeTextView = (TextView) findViewById(R.id.changeTextView);
    daysRangeTextView = (TextView) findViewById(R.id.daysRangeTextView);

    // Sends a message to the LogCat
    Log.d(TAG, "Before URL Creation " + stockSymbol);

    // Create the YQL query
    final String yqlURL = yahooURLFirst + stockSymbol + yahooURLSecond;

Answer 1

在onClick方法中，您将stockSymbol声明为局部变量。不要这样做，而是使用父类中定义的stockSymbol。

Answer 2

这是一个常见的范围问题。您在StockSymbol方法中声明了一个新的onClick字符串。要解决此问题，只需更改行

即可

String stockSymbol = stock.getText().toString();

到

stockSymbol = stock.getText().toString();

Answer 3

或者如果你想开心（？）解决方案。将变量设置为视图的标记值。

  public void onClick(View v) {
            // get the name from edittext and storing into string variable
            String stockSymbol = stock.getText().toString();

           // binding name to the textview
           ticker.setText("Stock Ticker is: " + stockSymbol);
           ticker.setTag(stockSymbol);
       }

分配值。

final String yqlURL = ticker.getTag();

Answer 4

似乎还没有从我的textview传递变量。这是一个更完整的代码版本，其中从OnClick侦听器中删除了String。爱德华 - 我试图实施你的“有趣”解决方法，但无济于事。

String stockSymbol = "D";

// Used to make the URL to call for XML data
String yahooURLFirst = "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.quote%20where%20symbol%20in%20(%22";
String yahooURLSecond = "%22)&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys";

EditText stock;
Button btnquote;
TextView ticker;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_stock_info);

    stock = (EditText) findViewById(R.id.stock);
    ticker = (TextView) findViewById(R.id.ticker);
    btnquote = (Button) findViewById(R.id.btnquote);
    btnquote.setOnClickListener(new OnClickListener() {

        public void onClick(View v) {
            // get the name from edittext and storing into string variable
            stockSymbol = stock.getText().toString();
            // binding name to the textview
            ticker.setText(stockSymbol);
        }
    });       

    // Initialize TextViews
    companyNameTextView = (TextView) findViewById(R.id.companyNameTextView);
    yearLowTextView = (TextView) findViewById(R.id.yearLowTextView);
    yearHighTextView = (TextView) findViewById(R.id.yearHighTextView);
    daysLowTextView = (TextView) findViewById(R.id.daysLowTextView);
    daysHighTextView = (TextView) findViewById(R.id.daysHighTextView);
    lastTradePriceOnlyTextView = (TextView) findViewById(R.id.lastTradePriceOnlyTextView);
    changeTextView = (TextView) findViewById(R.id.changeTextView);
    daysRangeTextView = (TextView) findViewById(R.id.daysRangeTextView);

    // Sends a message to the LogCat
    Log.d(TAG, "Before URL Creation " + stockSymbol);


    // Create the YQL query
    final String yqlURL = yahooURLFirst + stockSymbol + yahooURLSecond;

传递变量以通过Android项目使用

4 个答案: