Scott Main | 70645e3 | 2011-12-13 16:06:16 -0800 | [diff] [blame] | 1 | page.title=Sending Content to Other Apps |
| 2 | parent.title=Sharing Content |
| 3 | parent.link=index.html |
| 4 | |
| 5 | trainingnavtop=true |
| 6 | next.title=Receiving Content from Other Apps |
| 7 | next.link=receive.html |
| 8 | |
| 9 | @jd:body |
| 10 | |
| 11 | <div id="tb-wrapper"> |
| 12 | <div id="tb"> |
| 13 | |
| 14 | <!-- table of contents --> |
| 15 | <h2>This lesson teaches you to</h2> |
| 16 | <ol> |
| 17 | <li><a href="#send-text-content">Send Text Content</a></li> |
| 18 | <li><a href="#send-binary-content">Send Binary Content</a></li> |
| 19 | <li><a href="#send-multiple-content">Send Multiple Pieces of Content</a></li> |
| 20 | </ol> |
| 21 | |
| 22 | <!-- other docs (NOT javadocs) --> |
| 23 | <h2>You should also read</h2> |
| 24 | <ul> |
| 25 | <li><a href="{@docRoot}guide/topics/intents/intents-filters.html">Intents and |
| 26 | Intent Filters</a></li> |
| 27 | </ul> |
| 28 | |
| 29 | </div> |
| 30 | </div> |
| 31 | |
| 32 | <p>When you construct an intent, you must specify the action you want the intent to "trigger." |
| 33 | Android defines several actions, including {@link android.content.Intent#ACTION_SEND} which, as |
| 34 | you can probably guess, indicates that the intent is sending data from one activity to another, |
| 35 | even across process boundaries. To send data to another activity, all you need to do is speicify |
| 36 | the data and its type, the system will identify compatible receiving activities and display them |
| 37 | to the user (if there are multiple options) or immediately start the activity (if there is only |
| 38 | one option). Similarly, you can advertise the data types that your activities support receiving |
| 39 | from other applications by specifying them in your manifest.</p> |
| 40 | |
| 41 | <p>Sending and receiving data between applications with intents is most commonly used for social |
| 42 | sharing of content. Intents allow users to share information quickly and easily, using their |
Adam Koch | 909fe93 | 2011-12-15 15:54:52 -0500 | [diff] [blame] | 43 | favorite applications.</p> |
Scott Main | 70645e3 | 2011-12-13 16:06:16 -0800 | [diff] [blame] | 44 | |
| 45 | <p><strong>Note:</strong> The best way to add a share action item to an |
| 46 | {@link android.app.ActionBar} is to use {@link android.widget.ShareActionProvider}, which became |
| 47 | available in API level 14. {@link android.widget.ShareActionProvider} is discussed in the lesson |
| 48 | about <a href="shareaction.html">Adding an Easy Share Action</a>.</p> |
| 49 | |
| 50 | |
| 51 | <h2 id="send-text-content">Send Text Content</h2> |
| 52 | |
| 53 | <div class="figure" style="width:220px"> |
| 54 | <img src="{@docRoot}images/training/sharing/share-text-screenshot.png" alt="" id="figure1" /> |
| 55 | <p class="img-caption"> |
| 56 | <strong>Figure 1.</strong> Screenshot of {@link android.content.Intent#ACTION_SEND} intent chooser |
| 57 | on a handset. |
| 58 | </p> |
| 59 | </div> |
| 60 | |
| 61 | <p>The most straightforward and common use of the {@link android.content.Intent#ACTION_SEND} |
| 62 | action is sending text content from one activity to another. For example, the built-in Browser |
| 63 | app can share the URL of the currently-displayed page as text with any application. This is useful |
| 64 | for sharing an article or website with friends via email or social networking. Here is the code to |
| 65 | implement this type of sharing:</p> |
| 66 | |
| 67 | <pre> |
| 68 | Intent sendIntent = new Intent(); |
| 69 | sendIntent.setAction(Intent.ACTION_SEND); |
| 70 | sendIntent.putExtra(Intent.EXTRA_TEXT, "This is my text to send."); |
| 71 | sendIntent.setType("text/plain"); |
| 72 | startActivity(sendIntent); |
| 73 | </pre> |
| 74 | |
| 75 | <p>If there's an installed application with a filter that matches |
| 76 | {@link android.content.Intent#ACTION_SEND} and MIME type text/plain, the Android system will run |
| 77 | it; if more than one application matches, the system displays a disambiguation dialog (a "chooser") |
| 78 | that allows the user to choose an app. If you call |
| 79 | {@link android.content.Intent#createChooser(android.content.Intent, CharSequence) |
| 80 | Intent.createChooser()} |
| 81 | for the intent, Android will <strong>always</strong> display the chooser. This has some |
| 82 | advantages:</p> |
| 83 | |
| 84 | <ul> |
| 85 | <li>Even if the user has previously selected a default action for this intent, the chooser will |
| 86 | still be displayed.</li> |
| 87 | <li>If no applications match, Android displays a system message.</li> |
| 88 | <li>You can specify a title for the chooser dialog.</li> |
| 89 | </ul> |
| 90 | |
| 91 | <p>Here's the updated code:</p> |
| 92 | |
| 93 | <pre> |
| 94 | Intent sendIntent = new Intent(); |
| 95 | sendIntent.setAction(Intent.ACTION_SEND); |
| 96 | sendIntent.putExtra(Intent.EXTRA_TEXT, "This is my text to send."); |
| 97 | sendIntent.setType("text/plain"); |
| 98 | startActivity(<strong>Intent.createChooser(sendIntent, getResources().getText(R.string.send_to)</strong>); |
| 99 | </pre> |
| 100 | |
| 101 | <p>The resulting dialog is shown in figure 1.</p> |
| 102 | |
| 103 | <p>Optionally, you can set some standard extras for the intent: |
| 104 | {@link android.content.Intent#EXTRA_EMAIL}, {@link android.content.Intent#EXTRA_CC}, |
| 105 | {@link android.content.Intent#EXTRA_BCC}, {@link android.content.Intent#EXTRA_SUBJECT}. However, |
| 106 | if the receiving application is not designed to use them, nothing will happen. You can use |
| 107 | custom extras as well, but there's no effect unless the receiving application understands them. |
| 108 | Typically, you'd use custom extras defined by the receiving application itself.</p> |
| 109 | |
| 110 | <p class="note"><strong>Note:</strong> Some e-mail applications, such as Gmail, expect a |
| 111 | {@link java.lang.String String[]} for extras like {@link android.content.Intent#EXTRA_EMAIL} and |
| 112 | {@link android.content.Intent#EXTRA_CC}, use |
| 113 | {@link android.content.Intent#putExtra(String,String[]) putExtra(String, String[])} to add these |
| 114 | to your intent.</p> |
| 115 | |
| 116 | |
| 117 | <h2 id="send-binary-content">Send Binary Content</h2> |
| 118 | |
| 119 | <p>Binary data is shared using the {@link android.content.Intent#ACTION_SEND} action combined with |
| 120 | setting the appropriate MIME type and placing the URI to the data in an extra named {@link |
| 121 | android.content.Intent#EXTRA_STREAM}. This is commonly used to share an image but can be used to |
| 122 | share any type of binary content:</p> |
| 123 | |
| 124 | <pre> |
| 125 | Intent shareIntent = new Intent(); |
| 126 | shareIntent.setAction(Intent.ACTION_SEND); |
| 127 | shareIntent.putExtra(Intent.EXTRA_STREAM, uriToImage); |
| 128 | shareIntent.setType("image/jpeg"); |
| 129 | startActivity(Intent.createChooser(shareIntent, getResources().getText(R.string.send_to))); |
| 130 | </pre> |
| 131 | |
| 132 | <p>Note the following:</p> |
| 133 | <ul> |
| 134 | <li>You can use a MIME type of {@code "*/*"}, but this will only match activities that are able to |
| 135 | handle generic data streams.</li> |
| 136 | <li>The receiving application needs permission to access the data the {@link android.net.Uri} |
| 137 | points to. There are a number of ways to handle this: |
| 138 | <ul> |
| 139 | <li>Write the data to a file on external/shared storage (such as the SD card), which all apps |
| 140 | can read. Use {@link android.net.Uri#fromFile(java.io.File) Uri.fromFile()} to create the |
| 141 | {@link android.net.Uri} that can be passed to the share intent. However, keep in mind that not |
| 142 | all applications process a {@code file://} style {@link android.net.Uri}.</li> |
| 143 | <li>Write the data to a file in your own application directory using {@link |
| 144 | android.content.Context#openFileOutput(java.lang.String, int) openFileOutput()} with mode {@link |
| 145 | android.content.Context#MODE_WORLD_READABLE} after which {@link |
| 146 | android.content.Context#getFileStreamPath(java.lang.String) getFileStreamPath()} can be used to |
| 147 | return a {@link java.io.File}. As with the previous option, {@link |
| 148 | android.net.Uri#fromFile(java.io.File) Uri.fromFile()} will create a {@code file://} style {@link |
| 149 | android.net.Uri} for your share intent.</li> |
| 150 | <li>Media files like images, videos and audio can be scanned and added to the system {@link |
| 151 | android.provider.MediaStore} using {@link |
| 152 | android.media.MediaScannerConnection#scanFile(android.content.Context, java.lang.String[], |
| 153 | java.lang.String[], android.media.MediaScannerConnection.OnScanCompletedListener) scanFile()}. The |
| 154 | {@link |
| 155 | android.media.MediaScannerConnection.OnScanCompletedListener#onScanCompleted(java.lang.String, |
| 156 | android.net.Uri) onScanCompleted()} callback returns a {@code content://} style {@link |
| 157 | android.net.Uri} suitable for including in your share intent.</li> |
| 158 | <li>Images can be inserted into the system {@link android.provider.MediaStore} using {@link |
| 159 | android.provider.MediaStore.Images.Media#insertImage(android.content.ContentResolver, |
| 160 | android.graphics.Bitmap, java.lang.String, java.lang.String) insertImage()} which will return a |
| 161 | {@code content://} style {@link android.net.Uri} suitable for including in a share intent.</li> |
| 162 | <li>Store the data in your own {@link android.content.ContentProvider}, make sure that other |
| 163 | apps have the correct permission to access your provider (or use <a |
| 164 | href="{@docRoot}guide/topics/security/security.html#uri">per-URI permissions</a>).</li> |
| 165 | </ul> |
| 166 | </li> |
| 167 | </ul> |
| 168 | |
| 169 | |
| 170 | <h2 id="send-multiple-content">Send Multiple Pieces of Content</h2> |
| 171 | |
| 172 | <p>To share multiple pieces of content, use the {@link android.content.Intent#ACTION_SEND_MULTIPLE} |
| 173 | action together with a list of URIs pointing to the content. The MIME type varies according to the |
| 174 | mix of content you're sharing. For example, if you share 3 JPEG images, the type is still {@code |
| 175 | "image/jpeg"}. For a mixture of image types, it should be {@code "image/*"} to match an activity |
| 176 | that handles any type of image. You should only use {@code "*/*"} if you're sharing out a wide |
| 177 | variety of types. As previously stated, it's up to the receiving application to parse and process |
| 178 | your data. Here's an example:</p> |
| 179 | |
| 180 | <pre> |
| 181 | ArrayList<Uri> imageUris = new ArrayList<Uri>(); |
| 182 | imageUris.add(imageUri1); // Add your image URIs here |
| 183 | imageUris.add(imageUri2); |
| 184 | |
| 185 | Intent shareIntent = new Intent(); |
| 186 | shareIntent.setAction(Intent.ACTION_SEND_MULTIPLE); |
| 187 | shareIntent.putParcelableArrayListExtra(Intent.EXTRA_STREAM, imageUris); |
| 188 | shareIntent.setType("image/*"); |
| 189 | startActivity(Intent.createChooser(shareIntent, "Share images to..")); |
| 190 | </pre> |
| 191 | |
| 192 | <p>As before, make sure the provided {@link android.net.Uri URIs} point to data that a receiving |
| 193 | application can access.</p> |
| 194 | |